Molecules

26 pages, 6377 KiB

Open AccessReview

Targeting Epigenetic Changes Mediated by Members of the SMYD Family of Lysine Methyltransferases

by Alyssa Padilla, John F. Manganaro, Lydia Huesgen, Deborah A. Roess, Mark A. Brown and Debbie C. Crans

Molecules 2023, 28(4), 2000; https://doi.org/10.3390/molecules28042000 - 20 Feb 2023

Cited by 7 | Viewed by 4589

Abstract

A comprehensive understanding of the mechanisms involved in epigenetic changes in gene expression is essential to the clinical management of diseases linked to the SMYD family of lysine methyltransferases. The five known SMYD enzymes catalyze the transfer of donor methyl groups from S-adenosylmethionine [...] Read more.

A comprehensive understanding of the mechanisms involved in epigenetic changes in gene expression is essential to the clinical management of diseases linked to the SMYD family of lysine methyltransferases. The five known SMYD enzymes catalyze the transfer of donor methyl groups from S-adenosylmethionine (SAM) to specific lysines on histones and non-histone substrates. SMYDs family members have distinct tissue distributions and tissue-specific functions, including regulation of development, cell differentiation, and embryogenesis. Diseases associated with SMYDs include the repressed transcription of SMYD1 genes needed for the formation of ion channels in the heart leading to heart failure, SMYD2 overexpression in esophageal squamous cell carcinoma (ESCC) or p53-related cancers, and poor prognosis associated with SMYD3 overexpression in more than 14 types of cancer including breast cancer, colon cancer, prostate cancer, lung cancer, and pancreatic cancer. Given the importance of epigenetics in various pathologies, the development of epigenetic inhibitors has attracted considerable attention from the pharmaceutical industry. The pharmacologic development of the inhibitors involves the identification of molecules regulating both functional SMYD SET (Suppressor of variegation, Enhancer of Zeste, Trithorax) and MYND (Myeloid-Nervy-DEAF1) domains, a process facilitated by available X-ray structures for SMYD1, SMYD2, and SMYD3. Important leads for potential pharmaceutical agents have been reported for SMYD2 and SMYD3 enzymes, and six epigenetic inhibitors have been developed for drugs used to treat myelodysplastic syndrome (Vidaza, Dacogen), cutaneous T-cell lymphoma (Zoinza, Isrodax), and peripheral T-cell lymphoma (Beleodag, Epidaza). The recently demonstrated reversal of SMYD histone methylation suggests that reversing the epigenetic effects of SMYDs in cancerous tissues may be a desirable target for pharmacological development. Full article

(This article belongs to the Special Issue Exploring Bioactive Organic Compounds for Drug Discovery)

► Show Figures

Figure 1

15 pages, 5016 KiB

Open AccessArticle

Femtosecond Time-Resolved Observation of Relaxation and Wave Packet Dynamics of the S1 State in Electronically Excited o-Fluoroaniline

by Bumaliya Abulimiti, Huan An, Zhenfei Gu, Xulan Deng, Bing Zhang, Mei Xiang and Jie Wei

Molecules 2023, 28(4), 1999; https://doi.org/10.3390/molecules28041999 - 20 Feb 2023

Cited by 1 | Viewed by 2125

Abstract

Quantum beat frequency is the basis for understanding interference effects and vibrational wave packet dynamics and has important applications. Using femtosecond time-resolved mass spectrometry and femtosecond time-resolved photoelectron image combined with theoretical calculations, we study the electronic excited-state relaxation of o-fluoraniline molecule [...] Read more.

Quantum beat frequency is the basis for understanding interference effects and vibrational wave packet dynamics and has important applications. Using femtosecond time-resolved mass spectrometry and femtosecond time-resolved photoelectron image combined with theoretical calculations, we study the electronic excited-state relaxation of o-fluoraniline molecule and the time-dependent evolution of vibrational wave packets between different eigenstates. After the molecule absorbs a photon of 288.3 nm and is excited to the S₁ state, intramolecular vibrational redistribution first occurs on the time scale τ₁ = 349 fs, and then the transition to the triplet state occurs through the intersystem crossing on the time scale τ₂ = 583 ps, and finally, the triplet state occurs decays slowly through the time scale τ₃ = 2074 ps. We find the intramolecular vibrational redistribution is caused by the 0⁰, 10b¹ and 16a¹ vibrational modes of the S_l state origin. That is, the 288.3 nm femtosecond laser excites the molecule to the S₁ state, and the continuous flow of the vibrational wave packet prepares a coherent superposition state of three vibrational modes. Through extracting the oscillation of different peak intensities in the photoelectron spectrum, we observe reversible changes caused by mutual interference of the S₁ 0⁰, S₁ 10b¹ and S₁ 16a¹ states when the wave packets flow. When the pump pulse is 280 nm, the beat frequency disappears completely. This is explained in terms of increases in the vibrational field density and characteristic period of oscillation, and statistical averaging makes the quantum effect smooth and indistinguishable. In addition, the Rydberg component of the S₁ state is more clearly resolved by combining experiment and theory. Full article

(This article belongs to the Special Issue Recent Advancements in Density Functional Theory (DFT) and beyond for Computational Chemistry)

► Show Figures

Figure 1

35 pages, 6797 KiB

Open AccessReview

Synthesis and Application Dichalcogenides as Radical Reagents with Photochemical Technology

by Cairong Wang, Yan Zhang, Kai Sun, Tingting Yu, Fei Liu and Xin Wang

Molecules 2023, 28(4), 1998; https://doi.org/10.3390/molecules28041998 - 20 Feb 2023

Cited by 6 | Viewed by 3278

Abstract

Dichalcogenides (disulfides and diselenides), as reactants for organic transformations, are important and widely used because of their potential to react with nucleophiles, electrophilic reagents, and radical precursors. In recent years, in combination with photochemical technology, the application of dichalcogenides as stable radical reagents [...] Read more.

Dichalcogenides (disulfides and diselenides), as reactants for organic transformations, are important and widely used because of their potential to react with nucleophiles, electrophilic reagents, and radical precursors. In recent years, in combination with photochemical technology, the application of dichalcogenides as stable radical reagents has opened up a new route to the synthesis of various sulfur- and selenium-containing compounds. In this paper, synthetic strategies for disulfides and diselenides and their applications with photochemical technology are reviewed: (i) Cyclization of dichalcogenides with alkenes and alkynes; (ii) direct selenylation/sulfuration of C−H/C−C/C−N bonds; (iii) visible-light-enabled seleno- and sulfur-bifunctionalization of alkenes/alkynes; and (iv) Direct construction of the C(sp)–S bond. In addition, the scopes, limitations, and mechanisms of some reactions are also described. Full article

(This article belongs to the Special Issue Synthesis and Modification of Nitrogen Heterocyclic Compounds)

► Show Figures

Figure 1

26 pages, 5685 KiB

Open AccessArticle

Synthesis of New Amino-Functionalized Porphyrins:Preliminary Study of Their Organophotocatalytic Activity

by Pol Torres, Marian Guillén, Marc Escribà, Joaquim Crusats and Albert Moyano

Molecules 2023, 28(4), 1997; https://doi.org/10.3390/molecules28041997 - 20 Feb 2023

Cited by 5 | Viewed by 4166

Abstract

The design, synthesis, and initial study of amino-functionalized porphyrins as a new class of bifunctional catalysts for asymmetric organophotocatalysis is described. Two new types of amine–porphyrin hybrids derived from 5,10,15,20-tetraphenylporphyrin (TPPH₂), in which a cyclic secondary amine moiety is covalently linked [...] Read more.

The design, synthesis, and initial study of amino-functionalized porphyrins as a new class of bifunctional catalysts for asymmetric organophotocatalysis is described. Two new types of amine–porphyrin hybrids derived from 5,10,15,20-tetraphenylporphyrin (TPPH₂), in which a cyclic secondary amine moiety is covalently linked either to a β-pyrrolic position (Type A) or to the p-position of one of the meso phenyl groups (Type B), were prepared by condensation, reductive amination, or amidation reactions from the suitable porphyrins (either formyl or methanamine derivatives) with readily available chiral amines. A preliminary study of the possible use of Type A amine–porphyrin hybrids as asymmetric, bifunctional organophotocatalysts was performed using the chiral, imidazolidinone-catalyzed Diels–Alder cycloaddition between cyclopentadiene 28 and trans-cinnamaldehyde 29 as a benchmark reaction. The yield and the stereochemical outcome of this process, obtained under purely organocatalytic conditions, under dual organophocatalysis, and under bifunctional organophotocatalysis, were compared. Full article

(This article belongs to the Special Issue Porphyrin-Based Compounds: Synthesis and Application)

► Show Figures

Figure 1

21 pages, 2820 KiB

Open AccessArticle

From Aquaculture to Aquaculture: Production of the Fish Feed Additive Astaxanthin by Corynebacterium glutamicum Using Aquaculture Sidestream

by Ina Schmitt, Florian Meyer, Irene Krahn, Nadja A. Henke, Petra Peters-Wendisch and Volker F. Wendisch

Molecules 2023, 28(4), 1996; https://doi.org/10.3390/molecules28041996 - 20 Feb 2023

Cited by 9 | Viewed by 3519

Abstract

Circular economy holds great potential to minimize the use of finite resources, and reduce waste formation by the creation of closed-loop systems. This also pertains to the utilization of sidestreams in large-scale biotechnological processes. A flexible feedstock concept has been established for the [...] Read more.

Circular economy holds great potential to minimize the use of finite resources, and reduce waste formation by the creation of closed-loop systems. This also pertains to the utilization of sidestreams in large-scale biotechnological processes. A flexible feedstock concept has been established for the industrially relevant Corynebacterium glutamicum, which naturally synthesizes the yellow C50 carotenoid decaprenoxanthin. In this study, we aimed to use a preprocessed aquaculture sidestream for production of carotenoids, including the fish feed ingredient astaxanthin by C. glutamicum. The addition of a preprocessed aquaculture sidestream to the culture medium did not inhibit growth, obviated the need for addition of several components of the mineral salt’s medium, and notably enhanced production of astaxanthin by an engineered C. glutamicum producer strain. Improved astaxanthin production was scaled to 2 L bioreactor fermentations. This strategy to improve astaxanthin production was shown to be transferable to production of several native and non-native carotenoids. Thus, this study provides a proof-of-principle for improving carotenoid production by C. glutamicum upon supplementation of a preprocessed aquaculture sidestream. Moreover, in the case of astaxanthin production it may be a potential component of a circular economy in aquaculture. Full article

(This article belongs to the Section Green Chemistry)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
Carotenoid Biosynthesis in C. glutamicum. Gene names are given next to the reactions catalyzed by their gene products. Heterologous genes are depicted with a grey box. GAP: Glyceraldehyde 3-phosphate; IPP: isopenthenyl pyrophosphate; DMAPP: dimethylallyl diphosphate; BABR: bisanhydrobacterioruberin; C.p.450: 2,2′-bis-(4-hydroxy-3-methybut-2enyl)-β,β-carotene; dxs: 1-deoxy-D-xylulose 5-phosphate synthase; idsA: geranylgeranyl pyrophosphate synthase; crtE: geranylgeranyl pyrophosphate synthase; crtB: phytoene synthase, crtI: phytoene desaturase; crtEb: lycopene elongase; crtYe/f: ϵ-cyclase; crtYg/h Ml: C50 carotenoid γ-cyclase from Micrococcus leuteus; lbtBCDs: subunit of C50 carotenoid β-cyclase (B) and lycopene elongase (C) from Dietzia sp. CQ4; lbtABDs: C50 carotenoid β-cyclase from Dietzia sp. CQ4; crtYPa: lycopene cyclase from Pantoea ananatis; crtWFp: β-carotene ketolase from Fulvimarina pelagi; crtZFp: β-carotene hydroxylase from Fulvimarina pelagi. Full article ">Figure 2
Nutrient composition of the aquaculture sidestream. Macro- and Micro-nutrients detected in an analysis of the untreated aquaculture sidestream performed by Eurofins Agraranalytik Deutschland GmbH. Nutrients below the detection limit are not represented. Full article ">Figure 3
Growth of C. glutamicum WT in AQ containing media. ∆OD600 nm, µmax, and decaprenoxanthin production after 48 h of C. glutamicum WT grown in a Biolector® flowerplate microcultivation system. The maximal OD600 nm difference from the initial OD600 nm during 48 h of cultivation is given as ∆OD600 nm. Values and error bars represent means and standard deviations of triplicate cultivations. Statistical significance in comparison to the cultivation in CGXII medium was assessed for ∆OD600 nm (marked in green) and decaprenoxanthin production (marked in black) in Student’s t-test (*** p < 0.0001, ** p < 0.001, * p < 0.05). (A) Growth on CGXII, CGXII with addition of 20% (v/v) AQ and CGXII with 20% (v/v) AQ replacing media components of the CGXII composition. (B) Growth on CGXII without carbon source, 5 to 40% (v/v) AQ were supplemented as replacement. (C) Growth on AQ as the sole medium component, with adjustment to pH 7 and the addition of MOPS buffer, glucose, (NH4)2SO4, and/or urea and phosphorous source (P). The last column represents the AQ based medium CGAQ. Full article ">Figure 4
Carotenoid production of C. glutamicum strains in AQ supplemented media. Carotenoid production of C. glutamicum MB001∆crtR (decaprenoxanthin), LYC6 (lycopene), CP1 (C.p.450), BABR1 (bisanhydrobacterioruberin), SAX1 (sarcinaxanthin), BETA4 (β-carotene), ZEA5 (zeaxanthin), CAN5 (canthaxanthin), ASTA* (astaxanthin) grown on CGXII, CGXII supplemented with 20% (v/v) AQ, or the AQ derived medium CGAQ for 48 h. Values and error bars represent means and standard deviations of triplicate cultivations. Statistical significance in comparison to the cultivation of each strain in CGXII medium was assessed in Student´s t-test (*** p < 0.0001, ** p < 0.001, * p < 0.05). Full article ">Figure 5
Batch-Fermentations. Progression of astaxanthin content (red squares), OD600 nm (green dots), agitator speed (grey line), and relative dissolved oxygen concentration (rDOS) (blue line) over time during 2 L batch fermentations with C. glutamicum ASTA* grown in CGXII medium (A) and CGXII medium supplemented with 20% (v/v) AQ (B). Full article ">

17 pages, 4273 KiB

Open AccessArticle

OAT3 Participates in Drug–Drug Interaction between Bentysrepinine and Entecavir through Interactions with M8—A Metabolite of Bentysrepinine—In Rats and Humans In Vitro

by Aijie Zhang, Fanlong Yang, Yang Yuan, Cai Li, Xiaokui Huo, Jing Liu, Shenzhi Zhou, Wei Li, Na Zhang, Jianfeng Liu, Shiqi Dong, Huirong Fan, Ying Peng and Jiang Zheng

Molecules 2023, 28(4), 1995; https://doi.org/10.3390/molecules28041995 - 20 Feb 2023

Cited by 4 | Viewed by 2045

Abstract

Bentysrepinine (Y101) is a novel phenylalanine dipeptide for the treatment of hepatitis B virus. Renal excretion played an important role in the elimination of Y101 and its metabolites, M8 and M9, in healthy Chinese subjects, although the molecular mechanisms of renal excretion and [...] Read more.

Bentysrepinine (Y101) is a novel phenylalanine dipeptide for the treatment of hepatitis B virus. Renal excretion played an important role in the elimination of Y101 and its metabolites, M8 and M9, in healthy Chinese subjects, although the molecular mechanisms of renal excretion and potential drug–drug interactions (DDIs) remain unclear. The present study aimed to determine the organic anion transporters (OATs) involved in the renal disposition of Y101 and to predict the potential DDI between Y101 and entecavir, the first-line agent against HBV and a substrate of OAT1/3. Pharmacokinetic studies and uptake assays using rat kidney slices, as well as hOAT1/3-HEK293 cells, were performed to evaluate potential DDI. The co-administration of probenecid (an inhibitor of OATs) significantly increased the plasma concentrations and area under the plasma concentration–time curves of M8 and M9 but not Y101, while reduced renal clearance and the cumulative urinary excretion of M8 were observed in rats. The time course of Y101 and M8 uptake via rat kidney slices was temperature-dependent. Moreover, the uptake of M8 was inhibited significantly by probenecid and benzylpenicillin, but not by p-aminohippurate or tetraethyl ammonium. M8 was found to be a substrate of hOAT3, but Y101 is not a substrate of either hOAT1 or hOAT3. Additionally, the entecavir inhibited the uptake of M8 in the hOAT3-transfected cells and rat kidney slices in vitro. Interestingly, no significant changes were observed in the pharmacokinetic parameters of Y101, M8 or entecavir, regardless of intravenous or oral co-administration of Y101 and entecavir in rats. In conclusion, M8 is a substrate of OAT3 in rats and humans. Furthermore, M8 also mediates the DDI between Y101 and entecavir in vitro, mediated by OAT3. We speculate that it would be safe to use Y101 with entecavir in clinical practice. Our results provide useful information with which to predict the DDIs between Y101 and other drugs that act as substrates of OAT3. Full article

(This article belongs to the Special Issue New Advances in Drug Metabolism and Pharmacokinetics)

► Show Figures

Figure 1

12 pages, 1892 KiB

Open AccessCommunication

Low-Coordinate Mixed Ligand NacNac Complexes of Rare Earth Metals

by Svetlana V. Klementyeva, Taisiya S. Sukhikh, Pavel A. Abramov and Andrey I. Poddel’sky

Molecules 2023, 28(4), 1994; https://doi.org/10.3390/molecules28041994 - 20 Feb 2023

Cited by 3 | Viewed by 2611

Abstract

We report the synthesis and characterization of two types of new mixed-ligand rare earth complexes: tetracoordinate (NacNac^Mes)Ln(BIAN^dipp) (Ln = Dy (1), Er (2) and Y (3)) and pentacoordinate (NacNac^Mes)Ln(AP^dipp)(THF) [...] Read more.

We report the synthesis and characterization of two types of new mixed-ligand rare earth complexes: tetracoordinate (NacNac^Mes)Ln(BIAN^dipp) (Ln = Dy (1), Er (2) and Y (3)) and pentacoordinate (NacNac^Mes)Ln(AP^dipp)(THF) (Ln = Dy (4), Er (5) and Y (6)). The first three compounds were prepared by the reaction of [(BIAN^Dipp)LnI] with potassium β-diketiminate. The salt metathesis of β-diketiminato-supported rare earth dichlorides (NacNac^Mes)LnCl₂(THF)₂ with sodium o-amidophenolate results in compounds 4–6. The crystal structures of complexes 1–6 were determined by single-crystal analysis. The combination of bulky monoanionic N-mesityl-substituted β-diketiminates with sterically hindered redox-active ligands led to the very low coordination numbers of rare earths and strong distortion of the chelate ligands. Full article

(This article belongs to the Special Issue Molecules in 2023)

► Show Figures

Figure 1

17 pages, 4520 KiB

Open AccessArticle

Flow-Based Fmoc-SPPS Preparation and SAR Study of Cathelicidin-PY Reveals Selective Antimicrobial Activity

by Shama Dissanayake, Junming He, Sung H. Yang, Margaret A. Brimble, Paul W. R. Harris and Alan J. Cameron

Molecules 2023, 28(4), 1993; https://doi.org/10.3390/molecules28041993 - 20 Feb 2023

Cited by 6 | Viewed by 3158

Abstract

Antimicrobial peptides (AMPs) hold promise as novel therapeutics in the fight against multi-drug-resistant pathogens. Cathelicidin-PY (NH₂-RKCNFLCKLKEKLRTVITSHIDKVLRPQG-COOH) is a 29-residue disulfide-cyclised antimicrobial peptide secreted as an innate host defence mechanism by the frog Paa yunnanensis (PY) and reported to possess broad-spectrum antibacterial [...] Read more.

Antimicrobial peptides (AMPs) hold promise as novel therapeutics in the fight against multi-drug-resistant pathogens. Cathelicidin-PY (NH₂-RKCNFLCKLKEKLRTVITSHIDKVLRPQG-COOH) is a 29-residue disulfide-cyclised antimicrobial peptide secreted as an innate host defence mechanism by the frog Paa yunnanensis (PY) and reported to possess broad-spectrum antibacterial and antifungal properties, exhibiting low cytotoxic and low hemolytic activity. Herein, we detail the total synthesis of cathelicidin-PY using an entirely on-resin synthesis, including assembly of the linear sequence by rapid flow Fmoc-SPPS and iodine-mediated disulfide bridge formation. By optimising a synthetic strategy to prepare cathelicidin-PY, this strategy was subsequently adapted to prepare a bicyclic head-to-tail cyclised derivative of cathelicidin-PY. The structure-activity relationship (SAR) of cathelicidin-PY with respect to the N-terminally positioned disulfide was further probed by preparing an alanine-substituted linear analogue and a series of lactam-bridged peptidomimetics implementing side chain to side chain cyclisation. The analogues were investigated for antimicrobial activity, secondary structure by circular dichroism (CD), and stability in human serum. Surprisingly, the disulfide bridge emerged as non-essential to antimicrobial activity and secondary structure but was amenable to synthetic modification. Furthermore, the synthetic AMP and multiple analogues demonstrated selective activity towards Gram-negative pathogen E. coli in physiologically relevant concentrations of divalent cations. Full article

(This article belongs to the Special Issue Advances in Research of Short Peptides II)

► Show Figures

Graphical abstract

18 pages, 4616 KiB

Open AccessArticle

Impact of Sample Preparation Methods on Single-Cell X-ray Microscopy and Light Elemental Analysis Evaluated by Combined Low Energy X-ray Fluorescence, STXM and AFM

by Lucia Merolle, Lorella Pascolo, Luisa Zupin, Pietro Parisse, Valentina Bonanni, Gianluca Gariani, Sasa Kenig, Diana E. Bedolla, Sergio Crovella, Giuseppe Ricci, Stefano Iotti, Emil Malucelli, George Kourousias and Alessandra Gianoncelli

Molecules 2023, 28(4), 1992; https://doi.org/10.3390/molecules28041992 - 20 Feb 2023

Cited by 5 | Viewed by 2534

Abstract

Background: Although X-ray fluorescence microscopy is becoming a widely used technique for single-cell analysis, sample preparation for this microscopy remains one of the main challenges in obtaining optimal conditions for the measurements in the X-ray regime. The information available to researchers on sample [...] Read more.

Background: Although X-ray fluorescence microscopy is becoming a widely used technique for single-cell analysis, sample preparation for this microscopy remains one of the main challenges in obtaining optimal conditions for the measurements in the X-ray regime. The information available to researchers on sample treatment is inadequate and unclear, sometimes leading to wasted time and jeopardizing the experiment’s success. Many cell fixation methods have been described, but none of them have been systematically tested and declared the most suitable for synchrotron X-ray microscopy. Methods: The HEC-1-A endometrial cells, human spermatozoa, and human embryonic kidney (HEK-293) cells were fixed with organic solvents and cross-linking methods: 70% ethanol, 3.7%, and 2% paraformaldehyde; in addition, HEK-293 cells were subjected to methanol/ C₃H₆O treatment and cryofixation. Fixation methods were compared by coupling low-energy X-ray fluorescence with scanning transmission X-ray microscopy and atomic force microscopy. Results: Organic solvents lead to greater dehydration of cells, which has the most significant effect on the distribution and depletion of diffusion elements. Paraformaldehyde provides robust and reproducible data. Finally, the cryofixed cells provide the best morphology and element content results. Conclusion: Although cryofixation seems to be the most appropriate method as it allows for keeping cells closer to physiological conditions, it has some technical limitations. Paraformaldehyde, when used at the average concentration of 3.7%, is also an excellent alternative for X-ray microscopy. Full article

(This article belongs to the Special Issue Recent Advances and Future Trends in Sample Preparation II)

► Show Figures

Figure 1

Figure 1
Experimental plan of the experiment indicating the fixation protocols used for each type of sample. Paraformaldehyde (PFA); Ethanol (EtOH); Methanol (MeOH); Acetone (C3H6O). Full article ">Figure 2
STXM and XRF analysis of the HEC-1-A cell line. Absorption (Abs) and differential phase contrast (PhC) images, alongside with O, Na, Mg, and Scattering maps of HEC-1A endometrial cells fixed with three different methods: (a) EtOH 70% (mapped area 60 × 52 µm2), (b) PFA 2% (mapped area 68 × 68 µm2), and (c) PFA 3.7% (mapped area 52 × 52 µm2). Scale bars are 10 µm. (d) Normalised average XRF counts of O, Na, and Mg in HEC-1-A adenocarcinoma endometrial cells fixed with EtOH 70%, PFA 2%, and 3.7% evaluated on at least 6 cells/fixation method. (e) Min-to-max box plot comparing oxygen MFC as obtained by descriptive statistical analysis used to determine the coefficient of variation. A two-way ANOVA with multiple comparisons test was performed to test the statistical difference among the fixation methods. *** p < 0.001. The STXM images (Abs and PhC) and XRF images were acquired at 1500 eV excitation energy with a step size of 200 nm and 800 nm, respectively, and an acquisition time of 10 ms/pixel and 6 s/pixel, respectively. Full article ">Figure 3
AFM images with corresponding surface profiles of the HEC-1A endometrial cells. The first column shows the same cells depicted in <a href="#molecules-28-01992-f002" class="html-fig">Figure 2</a>, fixed with different methods: (a) EtOH, (b) PFA 2%, and (c) PFA 3.7%. The other pictures of panels a-c show additional cells prepared with the same three fixation methods. (d) Min-to-max box plot of HEC-1-A cell volume (µm3). Full article ">Figure 4
STXM and XRF analysis of human spermatozoa. Absorption (Abs) and phase contrast (PhC) images, together with O, Na and Mg maps of spermatozoa fixed with different methods: (a) EtOH 70% (mapped area 30 × 75 µm2), (b) PFA 2% (mapped area 70 × 70 µm2), and (c) PFA 3.7% (mapped area 70 × 70 µm2). Scale bars are 10 µm. (d) Normalised average XRF counts of O, Na, and Mg in spermatozoa fixed with EtOH 70%, PFA 2%, and 3.7% evaluated on at least 6–10 cells/patient/fixation method. (e) Min-to-max box plot comparing oxygen MFC as obtained by descriptive statistical analysis used to determine the coefficient of variation. A two-way ANOVA with multiple comparisons test was performed to test the statistical difference among the fixation methods. ** p < 0.005. The STXM images (Abs and PhC) and XRF images were acquired at 1500 eV excitation energy with a step size of 400 nm and 1 μm, respectively, and an acquisition time of 5 ms/pixel and 10 s/pixel, respectively. Full article ">Figure 5
AFM images of human spermatozoa fixed with different methods: (a) EtOH, (b) PFA 2%, and (c) PFA 3.7%. Scale bar is 10 µm. (d) Spermatozoa cell volume data expressed as a min-to-max box plot. A one-way ANOVA with multiple comparisons test was performed to test the statistical difference among the mean volumes obtained after fixations. ** p < 0.005 * p < 0.05. Full article ">Figure 6
STXM and XRF analysis of HEK-293 cells. Absorption (Abs) and phase contrast (PhC) images, together with O, Na, Mg, and Scattering maps of HEK-293 cells fixed with different methods: (a) EtOH 70% (mapped area 45 × 45 µm2), (b) PFA 2% (mapped area 34 × 34 µm2), (c) PFA 3.7% (mapped area 25 × 30 µm2), (d) 1:1 MeOH/C3H6O (mapped area 40 × 40 µm2), and (e) cryofixed (mapped area 50 × 50 µm2). Scale bars are 10 µm. (f) Normalised average X-ray fluorescence counts of O, Na, and Mg in HEK-293. A two-way ANOVA with multiple comparisons test was performed on at least on 4 cells/fixation method to test the statistical difference among the fixation methods. * p < 0.05, **** p < 0.0005. (g) Min-to-max box plot comparing oxygen MFC as obtained by descriptive statistical analysis used to determine the coefficient of variation. The STXM images (Abs and PhC) and XRF images were acquired at 1500 eV excitation energy with a step size of 500 nm and an acquisition time of 33 ms/pixel and 6 s/pixel, respectively. Full article ">Figure 7
AFM images with corresponding surface profiles collected on a selection of HEK-293 cells fixed with the different methods: (a) EtOH 70%, (b) PFA 2%, (c) PFA 3.7%, (d) 1:1 MeOH/C3H6O, and (e) cryofixed. Scale bar is 5 µm. Cell volume calculated from the AFM images collected on a selection of HEK-293 cells fixed with ethanol and PFA 3.7% and compared with the rest of the applied fixation methods (f). The second column shows the same cells depicted in <a href="#molecules-28-01992-f006" class="html-fig">Figure 6</a> (where a, b and e are rotated of 90 degrees left, 90 degrees right and 180 degrees respectively compared to <a href="#molecules-28-01992-f006" class="html-fig">Figure 6</a>), while the other columns depict additional cells prepared with the same five fixation methods. * p < 0.05, ** p < 0.005, *** p < 0.001, **** p < 0.0005. Full article ">

19 pages, 5104 KiB

Open AccessReview

Recent Progress in Vacuum Engineering of Ionic Liquids

by Yuji Matsumoto

Molecules 2023, 28(4), 1991; https://doi.org/10.3390/molecules28041991 - 20 Feb 2023

Cited by 1 | Viewed by 2391

Abstract

Since the discovery of ionic liquids (ILs) as a new class of liquid that can survive in a vacuum at room temperature, they have been aimed at being characterized with vacuum analysis techniques and used in vacuum processes for the last two decades. [...] Read more.

Since the discovery of ionic liquids (ILs) as a new class of liquid that can survive in a vacuum at room temperature, they have been aimed at being characterized with vacuum analysis techniques and used in vacuum processes for the last two decades. In this review, our state-of-the-art of the vacuum engineering of ILs will be introduced. Beginning with nanoscale vacuum deposition of IL films and their thickness-dependent ionic conductivity, there are presented some new applications of the ellipsometry to in situ monitoring of the thickness of IL films and their glass transitions, and of the surface thermal fluctuation spectroscopy to investigation of the rheological properties of IL films. Furthermore, IL-VLS (vapor-liquid-solid) growth, a vacuum deposition via IL, has been found successful, enhancing the crystallinity of vacuum-deposited crystals and films, and sometimes controlling their surface morphology and polymorphs. Among recent applications of ILs are the use of metal ions-containing IL and thin film nano IL gel. The former is proposed as a low temperature evaporation source of metals, such as Ta, in vacuum deposition, while the latter is demonstrated to work as a gate electrolyte in an electric double layer organic transistor. Full article

(This article belongs to the Special Issue Properties and Applications of Ionic Liquids-Based Advanced Materials)

► Show Figures

Figure 1

19 pages, 700 KiB

Open AccessReview

Renoprotective Effects of Tanshinone IIA: A Literature Review

by Zhengtao Chen, Haoyue Feng, Chuan Peng, Zehua Zhang, Qianghua Yuan, Hong Gao, Shiyun Tang and Chunguang Xie

Molecules 2023, 28(4), 1990; https://doi.org/10.3390/molecules28041990 - 20 Feb 2023

Cited by 15 | Viewed by 3784

Abstract

The kidney is an important organ in the human body, with functions such as urine production, the excretion of metabolic waste, the regulation of water, electrolyte and acid–base balance and endocrine release. The morbidity and mortality of kidney diseases are increasing year by [...] Read more.

The kidney is an important organ in the human body, with functions such as urine production, the excretion of metabolic waste, the regulation of water, electrolyte and acid–base balance and endocrine release. The morbidity and mortality of kidney diseases are increasing year by year worldwide, and they have become a serious public health problem. In recent years, natural products derived from fungi, plants and animals have become an important alternative source of treatment for kidney diseases because of their multiple pathways, multiple targets, safety, low toxicity and few side effects. Tanshinone IIA (Tan IIA) is a lipid-soluble diterpene quinone isolated from the Chinese herb Salvia miltiorrhiza, considered as a common drug for the treatment of cardiovascular diseases. As researchers around the world continue to explore its unknown biological activities, it has also been found to have a wide range of biological effects, such as anti-cancer, anti-oxidative stress, anti-inflammatory, anti-fibrotic, and hepatoprotective effects, among others. In recent years, many studies have elaborated on its renoprotective effects in various renal diseases, including diabetic nephropathy (DN), renal fibrosis (RF), uric acid nephropathy (UAN), renal cell carcinoma (RCC) and drug-induced kidney injury caused by cisplatin, vancomycin and acetaminophen (APAP). These effects imply that Tan IIA may be a promising drug to use against renal diseases. This article provides a comprehensive review of the pharmacological mechanisms of Tan IIA in the treatment of various renal diseases, and it provides some references for further research and clinical application of Tan IIA in renal diseases. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Figure 1

16 pages, 15552 KiB

Open AccessArticle

Chemical Profiling, Bioactive Properties, and Anticancer and Antimicrobial Potential of Juglans regia L. Leaves

by Natalia Żurek, Karolina Pycia, Agata Pawłowska, Leszek Potocki and Ireneusz Tomasz Kapusta

Molecules 2023, 28(4), 1989; https://doi.org/10.3390/molecules28041989 - 20 Feb 2023

Cited by 15 | Viewed by 2934

Abstract

The aim of this study was to assess the biological potential of the polyphenolic fraction isolated from J. regia leaves, collected in the Subcarpathian region (Poland). The phenolic profile was determined using the UPLC-PDA-MS/MS method. Biological activity was determined by evaluating the antioxidant, [...] Read more.

The aim of this study was to assess the biological potential of the polyphenolic fraction isolated from J. regia leaves, collected in the Subcarpathian region (Poland). The phenolic profile was determined using the UPLC-PDA-MS/MS method. Biological activity was determined by evaluating the antioxidant, anticancer, antibacterial, and antifungal effects. Prior to this study, the purified polyphenolic fraction was not been tested in this regard. A total of 40 phenolic compounds (104.28 mg/g dw) were identified, with quercetin 3-O-glucoside and quercetin pentosides dominating. The preparation was characterized by a high ability to chelate iron ions and capture O₂^•− and OH^• radicals (reaching IC₅₀ values of 388.61, 67.78 and 193.29 µg/mL, respectively). As for the anticancer activity, among the six tested cell lines, the preparation reduced the viability of the DLD-1, Caco-2, and MCF-7 lines the most, while in the antibacterial activity, among the seven tested strains, the highest susceptibility has been demonstrated against K. pneumoniae, S. pyogenes, and S. aureus. Depending on the needs, such a preparation can be widely used in the design of functional food and/or the cosmetics industry. Full article

(This article belongs to the Special Issue Natural Substances and Their Derivatives: In Search of New Structures, Activities and Applications)

► Show Figures

Figure 1

Figure 1
Effect of preparation of J. regia leaves on the cell viability of CCD 841 CoN, DLD-1, Caco-2, MCF-7, U87MG, U251MG, and SK-Mel-29. The cells were treated extracts in five concentrations (10–750 µg/mL) for 24, 48 and 72 h. The number of viable control (non-treated) cells at each time point served as 100%. Graphs represent mean values ± SD. Asterisks indicate a statistically significant differences (* p < 0.05, ** p < 0.01, *** p < 0.001) among samples according to Student’s t-test. Full article ">Figure 2
(A) Water and ethanolic J. regia extracts-mediated changes on microbial growth: G (−) Escherichia coli PCM2209, Klebsiella pneumoniae DSM 30104, Pseudomonas aeruginosa DSM 19880; G (+) Staphylococcus aureus DSM 104437, Streptococcus pyogenes PCM 2318, and Enterococcus faecalis; Candida albicans ATCC14053. The tested microorganisms were treated with J. regia leaves extracts at 10 mg/mL, 1 mg/mL, 0.1 mg/mL surface spotted onto the indicator lawn—NA agar (bacteria) and YPD agar (Candida) media. Representative micrographs of bacterial and yeast culture dishes; (B) diameter of growth inhibition (halo) of bacteria induced by walnut extracts; (a) 10 mg/mL water extract; (b) 10 mg/mL alcoholic extract; (c) 1 mg/mL alcoholic extract. The values are expressed as means ± SD. Letters indicate a statistically significant differences (capital letter < 0.01, small letter < 0.001) among samples according to ANOVA and HSD Tukey’s. Full article ">

17 pages, 4211 KiB

Open AccessArticle

Manipulation in Culture Conditions of Nanofrustulum shiloi for Enhanced Fucoxanthin Production and Isolation by Preparative Chromatography

by Ayşegül Erdoğan, Ayça Büşra Karataş, Dilan Demir, Zeliha Demirel, Merve Aktürk, Öykü Çopur and Meltem Conk-Dalay

Molecules 2023, 28(4), 1988; https://doi.org/10.3390/molecules28041988 - 20 Feb 2023

Cited by 5 | Viewed by 2502

Abstract

Microalgae produce a variety of high-value chemicals including carotenoids. Fucoxanthin is also a carotenoid that has many physiological functions and biological properties. For this reason, the cost-effective production of fucoxanthin at an industrial scale has gained significant attention. In the proposed study, fucoxanthin [...] Read more.

Microalgae produce a variety of high-value chemicals including carotenoids. Fucoxanthin is also a carotenoid that has many physiological functions and biological properties. For this reason, the cost-effective production of fucoxanthin at an industrial scale has gained significant attention. In the proposed study, fucoxanthin production was aimed to be increased by altering the culture conditions of N. shiloi. The effect of light intensity aeration rate, different nitrogen sources, and oxidative stress on the biomass and fucoxanthin productivity have been discussed. Based on these results, the fucoxanthin increased to 97.45 ± 2.64 mg/g by adjusting the light intensity to 50 µmol/m²s, and aeration rate at 5 L/min using oxidative stress through the addition of 0.1 mM H₂O₂ and 0.1 mM NaOCl to the culture medium. Fucoxanthin was then purified with preparative HPLC using C₃₀ carotenoid column (10 mm × 250 mm, 5 μm). After the purification procedure, Liquid chromatography tandem mass spectrometry (LC–MS/MS) and UV-vis spectroscopy were employed for the confirmation of fucoxanthin. This study presented a protocol for obtaining and purifying considerable amounts of biomass and fucoxanthin from diatom by manipulating culture conditions. With the developed methodology, N. shiloi could be evaluated as a promising source of fucoxanthin at the industrial scale for food, feed, cosmetic, and pharmaceutical industries. Full article

(This article belongs to the Section Analytical Chemistry)

► Show Figures

Figure 1

16 pages, 2477 KiB

Open AccessArticle

Design, Synthesis, and Pharmacology of New Triazole-Containing Quinolinones as CNS Active Agents

by Wennan Zhao, Mingxia Song, Yi Hua, Yangnv Zhu, Wenli Liu, Qishan Xia, Xianqing Deng and Yushan Huang

Molecules 2023, 28(4), 1987; https://doi.org/10.3390/molecules28041987 - 20 Feb 2023

Cited by 1 | Viewed by 2227

Abstract

Epilepsy and major depressive disorder are the two of the most common central nervous system (CNS) diseases. Clinicians and patients call for new antidepressants, antiseizure medicines, and in particular drugs for depression and epilepsy comorbidities. In this work, a dozen new triazole-quinolinones were [...] Read more.

Epilepsy and major depressive disorder are the two of the most common central nervous system (CNS) diseases. Clinicians and patients call for new antidepressants, antiseizure medicines, and in particular drugs for depression and epilepsy comorbidities. In this work, a dozen new triazole-quinolinones were designed, synthesized, and investigated as CNS active agents. All compounds reduced the immobility time significantly during the forced swim test (FST) in mice at the dosage of 50 mg/kg. Compounds 3f–3j gave superior performance over fluoxetine in the FST with more reductions of the immobility time. Compound 3g also reduced immobility time significantly in a tail suspension test (TST) at the dosage of 50 mg/kg, though its anti-immobility activity was inferior to that of fluoxetine. An open field test was carried out and it eliminated the false-positive possibility of 3g in the FST and TST, which complementarily supported the antidepressant activity of 3g. We also found that almost all compounds except 3k exhibited antiseizure activity in the maximal electroshock seizure (MES) model at 100 or 300 mg/kg. Compounds 3c, 3f, and 3g displayed the ED₅₀ of 63.4, 78.9, and 84.9 mg/kg, and TD₅₀ of 264.1, 253.5, and 439.9 mg/kg, respectively. ELISA assays proved that the mechanism for the antiseizure and antidepressant activities of compound 3g was via affecting the concentration of GABA in mice brain. The molecular docking study showed a good interaction between 3g and the amino acid residue of the GABA_A receptor. Excellent drug-like properties and pharmacokinetic properties of compound 3a–l were also predicted by Discovery Studio. These findings provided a new skeleton to develop agents for the treatment of epilepsy and depression comorbidities. Full article

(This article belongs to the Special Issue Design, Synthesis, and Evaluations of Antidepressant/Anticonvulsant/Anti-Alzheimer Agents)

► Show Figures

Figure 1

28 pages, 4608 KiB

Open AccessArticle

Surface Properties of Graffiti Coatings on Sensitive Surfaces Concerning Their Removal with Formulations Based on the Amino-Acid-Type Surfactants

by Marcin Bartman, Sebastian Balicki, Lucyna Hołysz and Kazimiera A. Wilk

Molecules 2023, 28(4), 1986; https://doi.org/10.3390/molecules28041986 - 20 Feb 2023

Cited by 3 | Viewed by 2413

Abstract

Water-in-oil (w/o) nanoemulsions stabilized with amino acid surfactants (AAS) are one example of nanotechnology detergents of the “brush on, wipe off”-type for removing graffiti coatings from different sensitive surfaces. The high-pressure homogenization (HPH) process was used to obtain the nanostructured fluids (NSFs), including [...] Read more.

Water-in-oil (w/o) nanoemulsions stabilized with amino acid surfactants (AAS) are one example of nanotechnology detergents of the “brush on, wipe off”-type for removing graffiti coatings from different sensitive surfaces. The high-pressure homogenization (HPH) process was used to obtain the nanostructured fluids (NSFs), including the non-toxic and eco-friendly components such as AAS, esterified vegetable oils, and ethyl lactate. The most effective NSF detergent was determined by response surface methodology (RSM) optimization. Afterwards, several surface properties, i.e., topography, wettability, surface free energy, and the work of water adhesion to surfaces before and after their coverage with the black graffiti paint, as well as after the removal of the paint layers by the eco-remover, were determined. It was found that the removal of graffiti with the use of the NSF detergent is more dependent on the energetic properties and microporous structure of the paint coatings than on the properties of the substrates on which the layers were deposited. The use of NSFs and knowledge of the surface properties could enable the development of versatile detergents that would remove unwanted contamination from various surfaces easily and in a controlled way. Full article

(This article belongs to the Special Issue Surfactants and Interfaces)

► Show Figures

Figure 1

17 pages, 21551 KiB

Open AccessArticle

Elucidating Flavonoid and Antioxidant Activity in Edible and Medicinal Herbs Woodwardia japonica (L.f.) Sm. Based on HPLC-ESI-TOF-MS and Artificial Neural Network Model: Response to Climatic Factors

by Xin Wang, Jianguo Cao, Lin Tian, Baodong Liu, Yawen Fan and Quanxi Wang

Molecules 2023, 28(4), 1985; https://doi.org/10.3390/molecules28041985 - 20 Feb 2023

Viewed by 2025

Abstract

Woodwardia japonica is a kind of great potential edible and medicinal fern. In a previous study, it was found that flavonoid and antioxidant activity of W. japonica from different sites were different. However, the cause of the differences has still been unclear, which [...] Read more.

Woodwardia japonica is a kind of great potential edible and medicinal fern. In a previous study, it was found that flavonoid and antioxidant activity of W. japonica from different sites were different. However, the cause of the differences has still been unclear, which has restricted the utilization of W. japonica. In this paper, flavonoid and antioxidant activity of W. japonica from nine different regions were determined with the method of a colorimetric assay with UV-VIS spectrophotometry and HPLC-ESI-TOF-MS, and the effects of climate factors on flavonoids and antioxidant activities were evaluated by mathematical modeling and statistical methods. The results showed: (1) total flavonoid content (TFC) of W. japonica from Wuyi Mountain (Jiangxi) was the highest, which might be related to the low temperature; (2) the differences of antioxidant activities of W. japonica might be related to precipitation; (3) five flavonols, two flavones and one isoflavone were tentatively identified in W. japonica; (4) flavonol and isoflavone might be affected by sunshine duration, and flavones were probably related to temperature. In conclusion, the effects of climate factors on flavonoids and antioxidants are significant, which would provide an important basis for further exploring the mechanism of climate affecting secondary metabolites. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

15 pages, 2079 KiB

Open AccessArticle

Integrating Siderophore Substructures in Thiol-Based Metallo-β-Lactamase Inhibitors

by Marco J. Rotter, Sabrina Zentgraf, Lilia Weizel, Denia Frank, Luisa D. Burgers, Steffen Brunst, Robert Fürst, Anna Proschak, Thomas A. Wichelhaus and Ewgenij Proschak

Molecules 2023, 28(4), 1984; https://doi.org/10.3390/molecules28041984 - 20 Feb 2023

Cited by 3 | Viewed by 2567

Abstract

Metallo beta lactamases (MBLs) are among the most problematic resistance mechanisms of multidrug-resistant Gram-negative pathogens due to their broad substrate spectrum and lack of approved inhibitors. In this study, we propose the integration of catechol substructures into the design of thiol-based MBL inhibitors, [...] Read more.

Metallo beta lactamases (MBLs) are among the most problematic resistance mechanisms of multidrug-resistant Gram-negative pathogens due to their broad substrate spectrum and lack of approved inhibitors. In this study, we propose the integration of catechol substructures into the design of thiol-based MBL inhibitors, aiming at mimicking bacterial siderophores for the active uptake by the iron acquisition system of bacteria. We synthesised two catechol-containing MBL inhibitors, as well as their dimethoxy counterparts, and tested them for in vitro inhibitory activity against NDM-1, VIM-1, and IMP-7. We demonstrated that the most potent catechol-containing MBL inhibitor is able to bind Fe³⁺ ions. Finally, we could show that this compound restores the antibiotic activity of imipenem in NDM-1-expressing K. pneumoniae, while leaving HUVEC cells completely unaffected. Thus, siderophore-containing MBL inhibitors might be a valuable strategy to overcome bacterial MBL-mediated resistance to beta lactam antibiotics. Full article

(This article belongs to the Collection Antibiotics & Superbugs: New Strategies to Combat Antimicrobial Resistance)

► Show Figures

Figure 1

Figure 1
Upper line: most advanced MBL inhibitors. Middle line: approved thiol-containing drugs shown to inhibit MBLs. Bottom line: Approved sideromycin cifederocol. Full article ">Figure 2
Design strategy of siderophore-containing MBL inhibitors. (A). X-ray structure of NDM-1 in complex with compound 1 (PDB code 6LJ0). Yellow and blue arrows indicate the positions which are sterically and chemically accessible for introduction of larger moieties. (B). Yellow and blue arrows indicate chemically tractable positions to introduce catechol moieties in compound 1, which results in the design of compounds 2 and 3. Full article ">Figure 3
Evaluation of compounds 2, 3, 12, and 18 in cytotoxicity assays. * Staurosporine (Stsp) was used as cytotoxic control. Full article ">Figure 4
Binding of compound 3 to Fe3+. (A). ITC measurement of the binding event. FeCl3 solution was titrated to the solution of compound 3. (B). Model fit of the 3:Fe3+ binding. (C). Model structure of two molecules of 3 (orange and purple sticks) binding to Fe3+ ion (cyan sphere). Full article ">Figure 5
Proposed binding mode of compound 3 to NDM-1. Starting from the X-ray structure of compound 1 in complex with NDM-1 (PDB code 6LJ0), the catechol moiety was introduced manually and the complex was subsequently energy minimised. Full article ">Scheme 1
(a) Meldrum´s acid, AcOH, i-PrOH/EtOAc, 75 °C, 3 h; (b) NaBH4, AcOH, DCM, 0 °C–r.t., 2.25 h; (c) Eschenmoser´s salt, MeOH, 70 °C, 18 h; (d) NaOH, 100 °C, 1 h, µw; (e) 1. SOCl2, DCM/DMF, 50 °C, 3 h, 2. t-Butyl-(2R)-2-piperidinecarboxylate 19, DIPEA, DCE/DMF, 90 °C, 1 h, µw; (f) Thioacetic acid, rt, 66 h; (g) TFA, DCM, 50 °C, o.n.; (h) NH3 (25%), H2O, 0 °C–rt, 2.5 h; and (i) BBr3, DCM, −78 °C–r.t., o.n. Full article ">Scheme 2
(a) 1. SOCl2, 90 °C, 2 h, 2. (R)-1-Boc-piperazine-2-carboxylic acid, DCM/pyridine/DMF, r.t., 20 h; (b) Benzyl bromide, KHCO3, 65 °C, 18 h; (c) HCl, DCM, r.t., o.n.; (d) 1. D-(-)-3-Acetylthio-2-methylpropionic acid, SOCl2, DCM/DMF, 0 °C–rt, o.n., 2. DIPEA, DCM, r.t., 18.5 h; (e) LiOH, H2O/THF, r.t., 4 h; and (f) BBr3, DCM, −78 °C–r.t., o.n. Full article ">

23 pages, 3305 KiB

Open AccessArticle

Multicomponent Domino Cyclization of Ethyl Trifluoropyruvate with Methyl Ketones and Amino Alcohols as A New Way to γ-Lactam Annulated Oxazacycles

by Marina V. Goryaeva, Olesya A. Fefelova, Yanina V. Burgart, Marina A. Ezhikova, Mikhail I. Kodess, Pavel A. Slepukhin, Vasily S. Gaviko and Victor I. Saloutin

Molecules 2023, 28(4), 1983; https://doi.org/10.3390/molecules28041983 - 20 Feb 2023

Cited by 1 | Viewed by 1804

Abstract

A new route to bicyclic γ-lactams was found, which was proposed as a three-component cyclization of ethyl trifluoropyruvate with methyl ketones and 1,2-, 1,3-amino alcohols. As a result, a series of trifluoromethyl-substituted tetrahydropyrrolo [2,1-b]oxazol-5-ones and tetrahydropyrrolo[2,1-b][1,3]oxazine-6-ones was synthesized, in [...] Read more.

A new route to bicyclic γ-lactams was found, which was proposed as a three-component cyclization of ethyl trifluoropyruvate with methyl ketones and 1,2-, 1,3-amino alcohols. As a result, a series of trifluoromethyl-substituted tetrahydropyrrolo [2,1-b]oxazol-5-ones and tetrahydropyrrolo[2,1-b][1,3]oxazine-6-ones was synthesized, in which the substituent at the nodal carbon atom was varied. The introduction of a twofold excess of ethyl trifluoropyruvate in reactions with amino alcohols and acetone made it possible to obtain the same bicycles, but functionalized with a hydroxyester fragment, which are formed due to four-component interactions of the reagents. Transformations with 2-butanone and aminoethanol lead predominantly to similar bicycles, while an analogous reaction with aminopropanol gives N-hydroxypropyl-2,3-dihydropyrrol-5-one. Almost all bicycles are formed as two diastereomers, the structure of which was determined using ¹H, ¹⁹F, ¹³C NMR spectroscopy, including two-dimensional experiments and XRD analysis. A domino mechanism for the formation of tetrahydropyrrolo[2,1-b]oxazacycles was proposed, which was confirmed by their stepwise synthesis through the preliminary preparation of the aldol and bis-aldol from ethyl trifluoropyruvate and methyl ketones. Full article

(This article belongs to the Special Issue Recent Developments in the Synthesis and Functionalization of Nitrogen Heterocycles)

► Show Figures

Graphical abstract

19 pages, 919 KiB

Open AccessReview

Research and Therapeutic Approaches in Stem Cell Genome Editing by CRISPR Toolkit

by Behrouz Mollashahi, Hamid Latifi-Navid, Iman Owliaee, Sara Shamdani, Georges Uzan, Saleh Jamehdor and Sina Naserian

Molecules 2023, 28(4), 1982; https://doi.org/10.3390/molecules28041982 - 20 Feb 2023

Cited by 7 | Viewed by 4753

Abstract

The most widely used genome editing toolkit is CRISPR (clustered regularly interspaced short palindromic repeats). It provides the possibility of replacing and modifying DNA and RNA nucleotides. Furthermore, with advancements in biological technology, inhibition and activation of the transcription of specific gene(s) has [...] Read more.

The most widely used genome editing toolkit is CRISPR (clustered regularly interspaced short palindromic repeats). It provides the possibility of replacing and modifying DNA and RNA nucleotides. Furthermore, with advancements in biological technology, inhibition and activation of the transcription of specific gene(s) has become possible. Bioinformatics tools that target the evolution of CRISPR-associated protein 9 (Cas9) turn this protein into a vehicle that is specific for a DNA or RNA region with single guide RNA (sgRNA). This toolkit could be used by researchers to investigate the function of stem cell gene(s). Here, in this review article, we cover recent developments and applications of this technique in stem cells for research and clinical purposes and discuss different CRISPR/Cas technologies for knock-out, knock-in, activation, or inhibition of gene expression. Additionally, a comparison of several deliveries and off-target detecting strategies is discussed. Full article

(This article belongs to the Section Molecular Structure)

► Show Figures

Figure 1

Figure 1
The zygote cell and its initial divisions (embryonic cells), which are considered totipotent stem cells, have the capacity to give rise to fully developed living organisms (body and placenta). Pluripotent stem cells, which can generate all cells that make up a live organism’s body following totipotent stem cells, are the next stage (mesoderm, endoderm, and ectoderm). Organoids are the new era for disease modeling, homeostasis, and development studies. Organoids derived from mesoderm, endoderm, and ectoderm are considered a new field of interest in biomedical research. Full article ">Figure 2
CRISPR toolkit. (A). CRISPR technology was originally used to create double-strand breaks in eukaryotic DNA (with a bacterial origin (Streptococcus pyogenes)). 1. In bacteria, crRNA and tracrRNA guide Cas9 to target the intended region. These RNAs are artificially synthetized as a unique sgRNA to be more applicable in other creatures (yellow) 2. crRNA and tracrRNA are widely used in multiple experimental systems (e.g., mouse embryo microinjections, RNP electroporation into mammalian cell lines, etc.) [<a href="#B91-molecules-28-01982" class="html-bibr">91</a>,<a href="#B92-molecules-28-01982" class="html-bibr">92</a>] 3. Twenty nucleotides complementary to the target site are used to identify the target area (these nucleotides are designed in a targeted manner). 4. Before these 20 nucleotides, there are three PAM nucleotides (5′-NGG-3′ in Streptococcus pyogenes Cas9 system) which are necessary for CRISPR/Cas9 function. (B). 1. In order to modify the bases in a targeted way, the Cas9 protein was altered to cut only one strand of DNA by changing one amino acid in Cas9 protein (nickase Cas9 [nCas9]). 2. Additionally, they coupled the different base editor domains to the Cas9 protein. (C). 1. Prime editing, the subsequent iteration of this technique, cuts a DNA strand by creating a cut at the intended location. 2 and 3. The sgRNA is made in such a way that its 3′-end complements the two sides of cut site, and its 5′-end can recognize the target site. 4. The reverse transcriptase enzyme turns 3′ sgRNA into cDNA using this 3′ end as a primer. 5. In the cut region, bases are designed for knock-in to produce highly accurate results. Full article ">

30 pages, 4579 KiB

Open AccessReview

Quinones as Promising Compounds against Respiratory Viruses: A Review

by Ivan Chan-Zapata, Rocío Borges-Argáez and Guadalupe Ayora-Talavera

Molecules 2023, 28(4), 1981; https://doi.org/10.3390/molecules28041981 - 20 Feb 2023

Cited by 8 | Viewed by 3820

Abstract

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for [...] Read more.

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for the treatment of influenza, but they cause side effects and lead to resistant viral strains. Likewise, aerosolized ribavirin is the only drug approved for the therapy of infections by the respiratory syncytial virus, but it possesses various limitations. On the other hand, no specific drugs are licensed to treat other viral respiratory diseases. In this sense, natural products and their derivatives have appeared as promising alternatives in searching for new compounds with antiviral activity. Besides their chemical properties, quinones have demonstrated interesting biological activities, including activity against respiratory viruses. This review summarizes the activity against respiratory viruses and their molecular targets by the different types of quinones (both natural and synthetic). Thus, the present work offers a general overview of the importance of quinones as an option for the future pharmacological treatment of viral respiratory infections, subject to additional studies that support their effectiveness and safety. Full article

(This article belongs to the Collection Featured Reviews in Natural Products Chemistry)

► Show Figures

Graphical abstract

20 pages, 4130 KiB

Open AccessReview

Advances on Hormones in Cosmetics: Illegal Addition Status, Sample Preparation, and Detection Technology

by Mengyue Li, Li Wang, Min Wang, Hua Zhao and Fengnian Zhao

Molecules 2023, 28(4), 1980; https://doi.org/10.3390/molecules28041980 - 20 Feb 2023

Cited by 5 | Viewed by 3173

Abstract

Owing to the rapid development of the cosmetic industry, cosmetic safety has become the focus of consumers’ attention. However, in order to achieve the desired effects in the short term, the illegal addition of hormones in cosmetics has emerged frequently, which could induce [...] Read more.

Owing to the rapid development of the cosmetic industry, cosmetic safety has become the focus of consumers’ attention. However, in order to achieve the desired effects in the short term, the illegal addition of hormones in cosmetics has emerged frequently, which could induce skin problems and even skin cancer after long-term use. Therefore, it is of great significance to master the illegal addition in cosmetics and effectively detect the hormones that may exist in cosmetics. In this review, we analyze the illegally added hormone types, detection values, and cosmetic types, as well as discuss the hormone risks in cosmetics for human beings, according to the data in unqualified cosmetics in China from 2017 to 2022. Results showed that although the frequency of adding hormones in cosmetics has declined, hormones are still the main prohibited substances in illegal cosmetics, especially facial masks. Because of the complex composition and the low concentration of hormones in cosmetics, it is necessary to combine efficient sample preparation technology with instrumental analysis. In order to give the readers a comprehensive overview of hormone analytical technologies in cosmetics, we summarize the advanced sample preparation techniques and commonly used detection techniques of hormones in cosmetics in the last decade (2012–2022). We found that ultrasound-assisted extraction, solid phase extraction, and microextraction coupled with chromatographic analysis are still the most widely used analytical technologies for hormones in cosmetics. Through the investigation of market status, the summary of sample pretreatment and detection technologies, as well as the discussion of their development trends in the future, our purpose is to provide a reference for the supervision of illegal hormone residues in cosmetics. Full article

(This article belongs to the Special Issue Development of Sample Preparation and Analytical Methods)

► Show Figures

Figure 1

Figure 1
Sample preparation and detection techniques for hormones in cosmetics are included in this review. Full article ">Figure 2
(a) The unqualified cosmetic batches containing hormones and (b) their detection values in China in recent six years (2017–2022). (c). Hormone types, frequency, and (d) cosmetic types in the above unqualified cosmetic batches. Full article ">Figure 3
(a) Scheme of sorption-based extraction technique for SPE. Reprinted with permission from Ref. [<a href="#B15-molecules-28-01980" class="html-bibr">15</a>] Copyright 2017 Journal of Separation Science. (b) Synthesis of plate@MWCNTs@MIPs and their application for SPE. Reprinted with permission from Ref. [<a href="#B52-molecules-28-01980" class="html-bibr">52</a>] Copyright 2018 Journal of Colloid and Interface Science. (c) Synthesis of magnetic MIPs and their application for MSPE. Reprinted with permission from Ref. [<a href="#B59-molecules-28-01980" class="html-bibr">59</a>] Copyright 2018 Journal of Separation Science. Full article ">Figure 4
(a) Scheme of the MIL as an extraction solvent for DLLME. Reprinted with permission from Ref. [<a href="#B66-molecules-28-01980" class="html-bibr">66</a>] Copyright 2020 Talanta. (b) Scheme for the synthesis of ACB[6]@poly(BMA-EDMA) monolith for PMME. Reprinted with permission from Ref. [<a href="#B68-molecules-28-01980" class="html-bibr">68</a>] Copyright 2015 New Journal of Chemistry. (c) Scheme of the preparation of porous monolithic polymer extraction bars and the procedure of µ-SPE. Reprinted with permission from Ref. [<a href="#B69-molecules-28-01980" class="html-bibr">69</a>] Copyright 2020 Journal of Separation Science. Full article ">Figure 5
(a) Scheme of the conventional immunoassay format approaches and the LFIA principle for on-site applications. Reprinted with permission from Ref. [<a href="#B25-molecules-28-01980" class="html-bibr">25</a>] Copyright 2021 Processes. (b) The application of a LFIA assay to rapidly test for dexamethasone in commercial facial masks. Reprinted with permission from Ref. [<a href="#B85-molecules-28-01980" class="html-bibr">85</a>] Copyright 2019 Analytical and Bioanalytical Chemistry. (c) The UCNPs-LFIA for triamcinolone acetonide detection. Reprinted with permission from Ref. [<a href="#B87-molecules-28-01980" class="html-bibr">87</a>] Copyright 2019 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. Full article ">

15 pages, 2690 KiB

Open AccessArticle

⁶⁸Ga-Labeled [Thz¹⁴]Bombesin(7–14) Analogs: Promising GRPR-Targeting Agonist PET Tracers with Low Pancreas Uptake

by Lei Wang, Ivica Jerolim Bratanovic, Zhengxing Zhang, Hsiou-Ting Kuo, Helen Merkens, Jutta Zeisler, Chengcheng Zhang, Ruiyan Tan, François Bénard and Kuo-Shyan Lin

Molecules 2023, 28(4), 1977; https://doi.org/10.3390/molecules28041977 - 20 Feb 2023

Cited by 5 | Viewed by 2364

Abstract

With overexpression in various cancers, the gastrin-releasing peptide receptor (GRPR) is a promising target for cancer imaging and therapy. However, the high pancreas uptake of reported GRPR-targeting radioligands limits their clinical application. Our goal was to develop ⁶⁸Ga-labeled agonist tracers for detecting [...] Read more.

With overexpression in various cancers, the gastrin-releasing peptide receptor (GRPR) is a promising target for cancer imaging and therapy. However, the high pancreas uptake of reported GRPR-targeting radioligands limits their clinical application. Our goal was to develop ⁶⁸Ga-labeled agonist tracers for detecting GRPR-expressing tumors with positron emission tomography (PET), and compare them with the clinically validated agonist PET tracer, [⁶⁸Ga]Ga-AMBA. Ga-TacBOMB2, TacBOMB3, and TacBOMB4, derived from [Thz¹⁴]Bombesin(7–14), were confirmed to be GRPR agonists by a calcium mobilization study, and their binding affinities (K_i(GRPR)) were determined to be 7.62 ± 0.19, 6.02 ± 0.59, and 590 ± 36.5 nM, respectively, via in vitro competition binding assays. [⁶⁸Ga]Ga-TacBOMB2, [⁶⁸Ga]Ga-TacBOMB3, and [⁶⁸Ga]Ga-AMBA clearly visualized PC-3 tumor xenografts in a PET imaging study. [⁶⁸Ga]Ga-TacBOMB2 showed comparable tumor uptake but superior tumor-to-background contrast ratios when compared to [⁶⁸Ga]Ga-AMBA. Moreover, [⁶⁸Ga]Ga-TacBOMB2 and [⁶⁸Ga]Ga-TacBOMB3 showed a much lower rate of uptake in the pancreas (1.30 ± 0.14 and 2.41 ± 0.72%ID/g, respectively) than [⁶⁸Ga]Ga-AMBA (62.4 ± 4.26%ID/g). In conclusion, replacing Met¹⁴ in the GRPR-targeting sequence with Thz¹⁴ retains high GRPR-binding affinity and agonist properties. With good tumor uptake and tumor-to-background uptake ratios, [⁶⁸Ga]Ga-TacBOMB2 is promising for detecting GRPR-expressing tumors. The much lower pancreas uptake of [⁶⁸Ga]Ga-TacBOMB2 and [⁶⁸Ga]Ga-TacBOMB3 suggests that [Thz¹⁴]Bombesin(7–14) is a promising targeting vector for the design of GRPR-targeting radiopharmaceuticals, especially for radioligand therapy application. Full article

(This article belongs to the Special Issue Design, Synthesis and Evaluation of Theranostic Radiopharmaceuticals)

► Show Figures

Figure 1

Figure 1
Chemical structures of (A) TacsBOMB2, TacsBOMB3, and TacsBOMB4; (B) TacsBOMB5; (C) TacBOMB2, TacBOMB3, and TacBOMB4; and (D) AMBA. The reduced peptide bond (inside the dashed brown circle) for the compounds in (A) is replaced with an amide bond (inside the dashed brown circle) for the compounds in (C). Full article ">Figure 2
Intracellular calcium efflux in PC-3 cells induced by various tested ligands. Error bars indicate standard deviation. Full article ">Figure 3
Displacement curves of [125I-Tyr4]Bombesin by Ga-TacBOMB2, Ga-TacBOMB3, Ga-TacBOMB4, and Ga-AMBA generated using GRPR-expressing PC-3 cells. Error bars indicate standard deviation. Full article ">Figure 4
Representative PET images of [68Ga]Ga-TacBOMB2, [68Ga]Ga-TacBOMB3, and [68Ga]Ga-AMBA acquired at 1 h post-injection in mice bearing PC-3 tumor xenografts. t: tumor; k: kidney; p/i: pancreas/intestines; bl: urinary bladder. Full article ">Figure 5
Uptake of [68Ga]Ga-TacBOMB2, [68Ga]Ga-TacBOMB3, and [68Ga]Ga-AMBA in PC-3 tumor xenografts and major organs/tissues of mice at 1 h post-injection. Error bars indicate standard deviation (n = 4). Full article ">Figure 6
Comparison of tumor-to-organ contrast ratios of [68Ga]Ga-TacBOMB2 and [68Ga]Ga-AMBA obtained from PC-3 tumor-bearing mice at 1 h post-injection. Error bars indicate standard deviation (n = 4). * p < 0.05; ** p < 0.01. Full article ">Figure 7
Comparison of [68Ga]Ga-TacBOMB2 with/without co-injection of [D-Phe6,Leu-NHEt13,des-Met14]Bombesin(6–14) on the uptake in PC-3 tumor xenografts and major organs/tissues in mice at 1 h post-injection. Error bars indicate standard deviation (n = 4). * p < 0.05; ** p < 0.01. Full article ">

12 pages, 5717 KiB

Open AccessArticle

Lactose and Galactose Promote the Crystallization of Human Galectin-10

by Yu-Fan Fu, Si-Cong Jiang, Zhong-Wei Zhang, Xin-Yue Yang, Zi-Lin Li, Jing Hu and Shu Yuan

Molecules 2023, 28(4), 1979; https://doi.org/10.3390/molecules28041979 - 19 Feb 2023

Cited by 2 | Viewed by 2680

Abstract

Galectin-10 (Gal-10) forms Charcot–Leyden crystals (CLCs), which play a key role in the symptoms of asthma and allergies and some other diseases. Gal-10 has a carbohydrate-binding site; however, neither the Gal-10 dimer nor the CLCs can bind sugars. To investigate the monomer–dimer equilibrium [...] Read more.

Galectin-10 (Gal-10) forms Charcot–Leyden crystals (CLCs), which play a key role in the symptoms of asthma and allergies and some other diseases. Gal-10 has a carbohydrate-binding site; however, neither the Gal-10 dimer nor the CLCs can bind sugars. To investigate the monomer–dimer equilibrium of Gal-10, high-performance size-exclusion chromatography (SEC) was employed to separate serial dilutions of Gal-10 with and without carbohydrates. We found that both the dimerization and crystallization of Gal-10 were promoted by lactose/galactose binding. A peak position shift for the monomer was observed after treatment with either lactose or galactose, implying that the polarity of the monomer was reduced by lactose/galactose binding. Further experiments indicated that alkaline conditions of pH 8.8 mimicked the lactose/galactose-binding environment, and the time interval between monomers and dimers in the chromatogram decreased from 0.8 min to 0.4 min. Subsequently, the electrostatic potential of the Gal-10 monomers was computed. After lactose/galactose binding, the top side of the monomer shifted from negatively charged to electrically neutral, allowing it to interact with the carbohydrate-binding site of the opposing subunit during dimerization. Since lactose/galactose promotes the crystallization of Gal-10, our findings implied that dairy-free diets (free of lactose/galactose) might be beneficial to patients with CLC-related diseases. Full article

(This article belongs to the Special Issue Recent Opinion on Protein-Carbohydrate Interactions)

► Show Figures

Figure 1

Figure 1
Concentration-dependent and time-dependent dimer formation of Gal-10 and the effects of carbohydrate binding. (A–C) Concentration-dependent dimerization of Gal-10. The protein was diluted to 100 μM, 10 μM, and 1 μM and incubated for 2 h. (D) Time-dependent dimer formation of Gal-10. The protein was diluted to 10 μM and incubated for 0 h, 2 h, 12 h, and 24 h. (E) Effects of sugars on Gal-10 monomer–dimer equilibrium. Gal-10 was diluted to 10 μM and incubated with 1 mM lactose, galactose, sucrose, or glucose for 2 h. The samples were analyzed by SEC HPLC using PBS–azide buffer (pH 7.4). Full article ">Figure 2
Effect of pH on Gal-10 monomer–dimer equilibrium. The protein was diluted to 10 μM in PBS–azide buffer at pH 8.8 (A), 7.4 (B), and 6.0 (C) with or without 1 mM lactose and incubated for 24 h. The samples were analyzed by SEC HPLC using PBS–azide buffer at pH 8.8 (A), 7.4 (B), and 6.0 (C). Quantitative data of Gal-10 monomers and dimers are shown on the left side of each panel. Bars represent the standard deviations of three independent replicates. Full article ">Figure 3
Effects of sugars on Gal-10 crystallization. Gal-10 was diluted to 10 μM in PBS–azide buffer with 0.01% Coomassie brilliant blue R-250 and incubated with or without 1 mM lactose, galactose, sucrose, or glucose for 24 h. The crystals were observed under a light microscope. Bar = 50 μM. Full article ">Figure 4
Effects of pH on Gal-10 crystallization. Gal-10 was diluted to 10 µM in PBS–azide buffer at pH 8.8, 7.4, and 6.0, with 0.01% Coomassie brilliant blue R-250 and incubated with or without 1 mM lactose for 24 h. The crystals were observed under a light microscope. Bar = 50 μM. Full article ">Figure 5
Shift in electrostatic potential may affect Gal-10 dimerization and crystallization. Given that Trp72, His53, and Asn65 bind with lactose (marked with green), the molecular surface and the electrostatic potential were re-computed by replacing Trp72, His53, and Asn65 with Ala to simulate the conditions of carbohydrate binding. Glu33 (marked with pale lavender) from one Gal-10 monomer subunit interacted with the carbohydrate-binding site of the opposing subunit when dimerizing. Then, lactose was expelled from the Gal-10 monomer after dimerization. The red-to-blue color gradient on the molecular surface indicates the electrostatic potential (red: −1.8; blue: 1.8). Full article ">

13 pages, 5549 KiB

Open AccessArticle

Reversible Luminescent Switching Induced by Heat/Water Treatment in a Zero-Dimensional Hybrid Antimony(Ⅲ) Chloride

by Ying-Chen Peng, Hao-Wei Lin, Sheng-Hua Zhou, Jian-Ce Jin, Ting-Hui Zhuang, Abdusalam Ablez, Ze-Ping Wang, Ke-Zhao Du and Xiao-Ying Huang

Molecules 2023, 28(4), 1978; https://doi.org/10.3390/molecules28041978 - 19 Feb 2023

Cited by 10 | Viewed by 2768

Abstract

Recently zero-dimensional (0-D) inorganic–organic metal halides (IOMHs) have become a promising class of optoelectronic materials. Herein, we report a new photoluminescent (PL) 0-D antimony(III)-based IOMH single crystal, namely [H₂BPZ][SbCl₅]·H₂O (BPZ = benzylpiperazine). Photophysical characterizations indicate that [H [...] Read more.

Recently zero-dimensional (0-D) inorganic–organic metal halides (IOMHs) have become a promising class of optoelectronic materials. Herein, we report a new photoluminescent (PL) 0-D antimony(III)-based IOMH single crystal, namely [H₂BPZ][SbCl₅]·H₂O (BPZ = benzylpiperazine). Photophysical characterizations indicate that [H₂BPZ][SbCl₅]·H₂O exhibits singlet/triplet dual-band emission. Density functional theory (DFT) calculations suggest that [H₂BPZ][SbCl₅]·H₂O has the large energy difference between singlet and triplet states, which might induce the dual emission in this compound. Temperature-dependent PL spectra analyses suggest the soft lattice and strong electron–phonon coupling in this compound. Thermogravimetric analysis shows that the water molecules in the lattice of the title crystal could be removed by thermal treatment, giving rise to a dehydrated phase of [H₂BPZ][SbCl₅]. Interestingly, such structural transformation is accompanied by a reversible PL emission transition between red light (630 nm, dehydrated phase) and yellow light (595 nm, water-containing phase). When being exposed to an environment with 77% relative humidity, the emission color of the dehydrated phase was able to change from red to yellow within 20 s, and the red emission could be restored after reheating. The red to yellow emission switching could be achieved in acetone with water concentration as low as 0.2 vol%. The reversible PL transition phenomenon makes [H₂BPZ][SbCl₅]·H₂O a potential material for luminescent water-sensing. Full article

(This article belongs to the Special Issue Design and Preparation of Organic Fluorescent Materials for Detection and Bio-Imaging)

► Show Figures

Figure 1

17 pages, 3426 KiB

Open AccessArticle

Influence of Mutations of Conserved Arginines on Neuropeptide Binding in the DPP III Active Site

by Antonija Tomić, Zrinka Karačić and Sanja Tomić

Molecules 2023, 28(4), 1976; https://doi.org/10.3390/molecules28041976 - 19 Feb 2023

Cited by 1 | Viewed by 1960

Abstract

Dipeptidyl peptidase III (DPP III), a zinc exopeptidase, is involved in the final steps of intercellular protein degradation and has a marked affinity for opioid peptides such as enkephalins and endomorphins. Recently, we characterized a number of neuropeptides as potential substrates and inhibitors [...] Read more.

Dipeptidyl peptidase III (DPP III), a zinc exopeptidase, is involved in the final steps of intercellular protein degradation and has a marked affinity for opioid peptides such as enkephalins and endomorphins. Recently, we characterized a number of neuropeptides as potential substrates and inhibitors of human DPP III and provided an explanation for their differential behavior. These studies prompted us to investigate the influence of the conserved R399 and R669 on neuropeptides binding to DPP III. Measuring kinetic parameters in inhibitory assays, we found that mutation of R669 to Ala or Met significantly reduced the inhibitory properties of the slow substrates tynorphin and valorphin, whereas the effects on binding of the good substrates Arg₂-2NA and Leu-enkephalin were small. Molecular dynamics simulations of wild-type (WT) and mutant DPP III complexes with Leu-enkephalin, tynorphin, valorphin, and Arg₂-2NA in conjunction with calculations of binding free energies revealed that the lower inhibitory potency of slow substrates in the R669A mutant can be explained by the lower binding affinity of tynorphin and the higher propensity of valorphin to hydrolyze in the mutant than in WT. The R399A mutation was shown to affect the binding and/or hydrolysis of both good and slow substrates, with the effects on Leu-enkephalin being the most pronounced. Full article

(This article belongs to the Special Issue Dipeptidyl Peptidase III: Physiological Role, Monitoring and Inhibition)

► Show Figures

Figure 1

15 pages, 1598 KiB

Open AccessArticle

Variation of Aroma Components of Pasteurized Yogurt with Different Process Combination before and after Aging by DHS/GC-O-MS

by Mu Zhao, Hongliang Li, Dongjie Zhang, Jie Li, Rong Wen, Hairan Ma, Tingting Zou, Yaqiong Hou and Huanlu Song

Molecules 2023, 28(4), 1975; https://doi.org/10.3390/molecules28041975 - 19 Feb 2023

Cited by 7 | Viewed by 2844

Abstract

Pasteurized yogurt is a healthy yogurt that can be stored in ambient temperature conditions. Dynamic headspace sampling (DHS) combined with gas chromatography-olfactory mass spectrometry (GC-O-MS), sensory evaluation, electronic nose (E-nose), and partial least squares discriminant analysis (PLS-DA) were used to analyze the flavor [...] Read more.

Pasteurized yogurt is a healthy yogurt that can be stored in ambient temperature conditions. Dynamic headspace sampling (DHS) combined with gas chromatography-olfactory mass spectrometry (GC-O-MS), sensory evaluation, electronic nose (E-nose), and partial least squares discriminant analysis (PLS-DA) were used to analyze the flavor changes of pasteurized yogurt with different process combinations before and after aging. The results of odor profiles showed that the sensory descriptors of fermented, sweet, and sour were greatly affected by different process combinations. The results of odor-active compounds and relative odor activity value (r-OAV) showed that the combination of the production process affected the overall odor profile of pasteurized yogurt, which was consistent with the sensory evaluation results. A total of 15 odor-active compounds of 38 volatile compounds were detected in pasteurized yogurt samples. r-OAV results revealed that hexanal, (E)-2-octenal, 2-heptanone, and butanoic acid may be important odor-active compounds responsible for off-odor in aged, pasteurized yogurt samples. PLS-DA and variable importance of projection (VIP) results showed that butanoic acid, hexanal, acetoin, decanoic acid, 1-pentanol, 1-nonanal, and hexanoic acid were differential compounds that distinguish pasteurized yogurt before and after aging. Full article

(This article belongs to the Special Issue Recent Advances of Spectrometric and Spectroscopic Techniques in Food Quality and Safety)

► Show Figures

Graphical abstract

13 pages, 3314 KiB

Open AccessArticle

Cinnamomum japonicum Siebold Branch Extracts Attenuate NO and ROS Production via the Inhibition of p38 and JNK Phosphorylation

by Jae Min Kim, Moon-Hee Choi and Ji Hye Yang

Molecules 2023, 28(4), 1974; https://doi.org/10.3390/molecules28041974 - 19 Feb 2023

Cited by 1 | Viewed by 1914

Abstract

Cinnamomum japonicum (CJ) is widely distributed in Asian countries like Korea, China, and Japan. Modern pharmacological studies have demonstrated that it exhibits various biological activities, including antioxidant and anti-inflammatory effects. However, most studies have confirmed the efficacy of its water extract but not [...] Read more.

Cinnamomum japonicum (CJ) is widely distributed in Asian countries like Korea, China, and Japan. Modern pharmacological studies have demonstrated that it exhibits various biological activities, including antioxidant and anti-inflammatory effects. However, most studies have confirmed the efficacy of its water extract but not that of its other extracts. Therefore, in this study, Cinnamomum japonicum Siebold branches (CJB: 70% EtOH extract) were separated using hexane, chloroform, ethyl acetate (CJB3), butanol, and water. Then, their antioxidative activities and phenolic contents were measured. Results revealed that the antioxidant activities and phenolic contents of CJB3 were higher than those of the other extracts. Further, the inhibitory and anti-inflammatory effect of CJB3 on lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) production and LPS-activated macrophages, respectively, was determined. CJB3 suppressed oxidative stress in LPS-activated cells and dose-dependently decreased LPS-stimulated ROS production. CJB3 reduced oxidative stress and reversed the glutathione decrease in LPS-activated RAW264.7 cells. The inhibitory and reducing effect of CJB3 on LPS-induced nitric oxide (NO) production and inducible NO synthase protein and messenger RNA levels, respectively, was investigated. CJB3 inhibited LPS-induced cytokine production and p38 and c-Jun N-terminal kinase (JNK) phosphorylation but not extracellular signal-regulated kinase phosphorylation. Overall, the study results suggest that CJB3 may exert its anti-inflammatory effects via the suppression of p38, JNK, and c-Jun activation. Full article

(This article belongs to the Special Issue New Approaches in the Extraction of Biomolecules from Plants–Molecular and Application Basics)

► Show Figures

Figure 1

Figure 1
Isolation and fractionation diagram of Cinnamomum japonicum Sieb. Branch. Full article ">Figure 2
Antioxidant effect of Cinnamomum japonicum Sieb. Branch. Antioxidant activity results: 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS). Full article ">Figure 3
HPLC profile of the CJB3 and standard mixtures using diode array detection at 280 nm. (A) Standards and (B) CJB3; the numbers indicate the following: (1) Epigallocatechin gallate (2) Epicatechin (3) p-Coumaric acid (4) Coumarin (5) Cinnamylacetate (6) Cinnamylalcohol (7) Trans-Cinnamic acid (8) Cinnamylaldehyde (9) Eugenol (10) Quercetin. Full article ">Figure 4
The inhibitory effect of CJB3 on LPS-induced oxidative stress in RAW264.7 cells. (A) The cytotoxicity of CJB3 in Raw 264.7 cells: cells were treated with CJB3 (10–100 μg/mL) for 24 h, and cytotoxicity was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. The effect of CJB3 on lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) production: cells were treated with CJB3 (30 or 100 μg/mL) for 1 h and incubated with LPS for 3 h. (B) Cells were stained with 10 μM 2′-7′-dichlorofluorescin diacetate (DCFH-DA) for 30 min at 37 °C. Intracellular fluorescence intensities were measured using a fluorescence microplate reader. (C) The glutathione (GSH) concentrations were measured in the cell lysates treated with LPS and/or 10–30 μg/mL CJB3 for 12 h. Data are expressed as the mean ± standard error of the mean (SE) of three replicates; ** p < 0.01, * p < 0.05, significant vs. vehicle-treated control; ## p < 0.01, # p < 0.05, significant vs. LPS alone. Full article ">Figure 5
CJB3-mediated inhibition of LPS-induced NO production and iNOS expression. (A) Nitric oxide (NO) production: cells were treated with CJB3 (10–100 μg/mL) and/or LPS for 15 h, and NO production was measured using a Griess reagent. (B) CJB3-mediated inhibition of inducible NO synthase (iNOS) expression in LPS-activated RAW264.7 cells: cells were pretreated with varying concentrations of CJB3 (10–100 μg/mL) for 1 h and incubated with LPS (100 ng/mL) for 12 h. iNOS protein levels in the cell lysates were measured using western blot. (C) The iNOS transcripts were analyzed using RT-PCR assays: cells were pretreated with 30–100 μg/mL CJB3 for 1 h and incubated with 100 ng/mL LPS for 6 h. Data are expressed as the mean ± SE of three replicates; ** p < 0.01., significant vs. vehicle-treated control; ## p < 0.01, significant vs. LPS alone. Full article ">Figure 6
CJB3-mediated inhibition of LPS-induced proinflammatory cytokine expression. (A,B) Measurement of the inhibitory effect of CJB3 on proinflammatory cytokine expression: cells were treated with 30 or 100 μg/mL CJB3 for 1 h and incubated with LPS for 6 h. (A) Tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) transcripts were monitored using RT-PCR assays. (B) Enzyme-linked immunosorbent assay (ELISA): TNF-α and IL-6 release into the culture supernatant was determined using ELISA. Data are expressed as the mean ± SE of three replicates; ** p < 0.01, significant vs. vehicle-treated control; ## p < 0.01, significant vs. LPS alone. Full article ">Figure 7
CJB3-induced specific inhibition of c-Jun, p38 and JNK phosphorylation in LPS-activated RAW264.7 cells. (A) Immunoblotting for total IκBα: cells were pretreated with CJB3 for 1 h before LPS stimulation for 15 min. Total IκBα in the cell lysate was immunoblotted. (B) The expression level of p65 protein in cells with nuclear fraction. Using Lamin as control for nuclear fraction. RAW264.7 cells were pretreated CJB3 for 1 h and then incubated with LPS for 3 h. (C) Immunoblotting for c-Jun and c-Fos phosphorylation: cells were pretreated with CJB3 for 1 h before LPS stimulation for 2 h, and cell lysates were immunoblotted to examine c-Jun and c-Fos phosphorylation. (D) Effect of CJB3 on LPS-induced phosphorylations of MAPKs: cells were treated with CJB3 for 1 h before LPS stimulation for 30 min. Data are expressed as the mean ± SE of three replicates; ** p < 0.01, significant vs. vehicle-treated control; # p < 0.05, ## p < 0.01, significant vs. LPS alone. Full article ">

35 pages, 5802 KiB

Open AccessReview

The Impact of Fluorination on the Design of Histone Deacetylase Inhibitors

by Duong Tien Anh, Nguyen Hai Nam, Brigitte Kircher and Daniel Baecker

Molecules 2023, 28(4), 1973; https://doi.org/10.3390/molecules28041973 - 19 Feb 2023

Cited by 6 | Viewed by 3530

Abstract

In recent years, histone deacetylases (HDACs) have emerged as promising targets in the treatment of cancer. The approach is to inhibit HDACs with drugs known as HDAC inhibitors (HDACis). Such HDACis are broadly classified according to their chemical structure, e.g., hydroxamic acids, benzamides, [...] Read more.

In recent years, histone deacetylases (HDACs) have emerged as promising targets in the treatment of cancer. The approach is to inhibit HDACs with drugs known as HDAC inhibitors (HDACis). Such HDACis are broadly classified according to their chemical structure, e.g., hydroxamic acids, benzamides, thiols, short-chain fatty acids, and cyclic peptides. Fluorination plays an important role in the medicinal–chemical design of new active representatives. As a result of the introduction of fluorine into the chemical structure, parameters such as potency or selectivity towards isoforms of HDACs can be increased. However, the impact of fluorination cannot always be clearly deduced. Nevertheless, a change in lipophilicity and, hence, solubility, as well as permeability, can influence the potency. The selectivity towards certain HDACs isoforms can be explained by special interactions of fluorinated compounds with the structure of the slightly different enzymes. Another aspect is that for a more detailed investigation of newly synthesized fluorine-containing active compounds, fluorination is often used for the purpose of labeling. Aside from the isotope ¹⁹F, which can be detected by nuclear magnetic resonance spectroscopy, the positron emission tomography of ¹⁸F plays a major role. However, to our best knowledge, a survey of the general effects of fluorination on HDACis development is lacking in the literature to date. Therefore, the aim of this review is to highlight the introduction of fluorine in the course of chemical synthesis and the impact on biological activity, using selected examples of recently developed fluorinated HDACis. Full article

(This article belongs to the Special Issue Bioorganic Chemistry: Current and Future Perspectives)

► Show Figures

Graphical abstract

10 pages, 1830 KiB

Open AccessArticle

Anti-Cancer Effects of Queen Bee Acid (10-Hydroxy-2-Decenoic Acid) and Its Cellular Mechanisms against Human Hepatoma Cells

by Zafer Saad Al Shehri, Abdullah D. Alanazi and Sultan F. Alnomasy

Molecules 2023, 28(4), 1972; https://doi.org/10.3390/molecules28041972 - 19 Feb 2023

Cited by 7 | Viewed by 3675

Abstract

Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer that occurs in hepatocytes. Although many chemical drugs, e.g., cisplatin, methotrexate, taxis, and doxorubicin are used to treat HCC, there have been numerous reports related to the side effects of these [...] Read more.

Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer that occurs in hepatocytes. Although many chemical drugs, e.g., cisplatin, methotrexate, taxis, and doxorubicin are used to treat HCC, there have been numerous reports related to the side effects of these drugs (e.g., emerging drug resistance, bone marrow failure, and gastrointestinal disorders). These issues led scientists to search for the novel anti-cancer drugs, mainly in natural products with greater efficiency and less toxicity. The current survey was intended to assess the anti-cancer effects of queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) and its cellular mechanisms against the human hepatoma cell line HepG2. Materials and Methods: The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to evaluate the effect of 10-HDA on the viability of HepG2 cells. The initial and late apoptosis in the HepG2 cells treated with 10-HDA were assessed by the Annexin-V (AV) assay. The level of the gene and protein expression of some apoptosis genes (e.g., caspase-3, Bcl-2-associated X protein (BAX), and B-cell lymphoma protein 2 (Bcl-2)), Poly (ADP-ribose) polymerases (PARP), and miRNA-34a (miR-34a), were measured by real-time PCR and Western blot. Results: The obtained findings revealed that HepG2 cell viability was markedly reduced (p < 0.01) following exposure to 10-HDA in a dose-dependent matter. The calculated half maximal cytotoxic concentration (CC50) value of 10-HDA was 59.6 µg/mL for HepG2 cells, while this value for normal THLE-3 cells was 106.4 µg/mL. We found that 10-HDA markedly elevated (p < 0.01) the percentage of necrotic and apoptotic cells from 0.94 to 9.7 and 27.6%, respectively. The real-time PCR results showed that the expression levels of the caspase-3, Bax, and miR-34a genes were significantly (p < 0.001) elevated. Contrary to these results, a significant (p < 0.01) reduction in the expression level of the Bcl2 gene was observed. The levels of protein expression of Caspase-3, PARP, and Bax were markedly elevated following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50. The level of protein expression of Bcl-2 was markedly reduced following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50 (p < 0.01). Conclusion: The current results confirmed the potent in vitro cytotoxic effects of 10-HDA on HepG2 cells with no significant cytotoxic effects on normal cells. Although its mechanisms of action have not been fully studied, the induction of apoptosis via different pathways was determined as one of the principle mechanisms of action of 10-HDA against HepG2 cells. Nevertheless, additional surveys must be performed to clearly understand the mechanisms of action and safety of this fatty acid. Full article

(This article belongs to the Special Issue Recent Advances in Anticancer Drugs III)

► Show Figures

Figure 1

Figure 1
Viability of HepG2 and THLE-3 cells exposed to different concentrations of queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) or 1 μM doxorubicin (DOX) for two days. * p < 0.05, ** p < 0.001 compared with the control; + p < 0.001 compared with DOX. The findings revealed that HepG2 cell viability was markedly reduced (p < 0.01) following exposure to 10-HDA in a dose-dependent manner. Full article ">Figure 2
Morphological changes in the structure of HepG2 cells treated with queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) at ½ the half maximal cytotoxic concentration (CC50) concentration for two days (A) and HepG2 cells that were not treated with 10-HDA (B). After exposure of HepG2 cells to 10-HDA (½ CC50 for two days), the cells showed smaller sizes and round shapes with marked cytoplasmic shrinkage (black arrows), while HepG2 cells with no treatment displayed a spindle shape with the same size. Full article ">Figure 3
The rate of apoptosis and necrotic cells following treatment with the queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) at ½ the half maximal cytotoxic concentration (CC50) and CC50. Data shown as mean ± SD (n = 3). * p < 0.001. We found that 10-HDA markedly elevated (p < 0.01) the number of necrotic and apoptotic cells. Meanwhile, exposure to 10-HDA at CC50 markedly elevated (p < 0.001) the number of necrotic and apoptotic cells. Full article ">Figure 4
The levels of gene expression of some apoptosis genes (Caspase-3, Bax, and Bcl-2) and the miR-34a gene in HepG2 cells after exposure to queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) at ¼ the half maximal cytotoxic concentration (CC50), ½ CC50, and CC50. Data shown as mean ± SD (n = 3). * p < 0.001. Real-time PCR results showed that the expression levels of the caspase-3 and Bax genes were significantly upregulated following exposure to 10-HDA. Contrary to these results, the exposure of HepG2 cells to 10-HDA caused a significant (p < 0.01) reduction in the expression levels of the Bcl2 and miR-34a genes. Full article ">Figure 5
Western blot (A) and relative protein expression levels (B) of some apoptosis genes (Caspase-3, Bcl-2-associated X protein (BAX), and B-cell lymphoma protein 2 (Bcl-2)) and poly [ADP-ribose] polymerase (PARP) in HepG2 cells after exposure to queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) at ¼ the half maximal cytotoxic concentration (CC50), ½ CC50, and CC50. Data shown as mean ± SD (n = 3). * p < 0.001. Based on the results of the Western blot assay, the levels of protein expression of Caspase-3, PARP, and Bax was markedly elevated following exposure of HepG2 cells to 10-HDA. In contrast to these results, the level of protein expression of Bcl-2 was markedly reduced following exposure of HepG2 cells to 10-HDA. Full article ">

16 pages, 2949 KiB

Open AccessArticle

A Natural Glucan from Black Bean Inhibits Cancer Cell Proliferation via PI3K-Akt and MAPK Pathway

by Peng Li, Yihua Hu, Lingmin Zhan, Jiaqi He, Jingwu Lu, Chunyan Gao, Weijun Du, Aiqin Yue, Jinzhong Zhao and Wuxia Zhang

Molecules 2023, 28(4), 1971; https://doi.org/10.3390/molecules28041971 - 19 Feb 2023

Cited by 3 | Viewed by 2132

Abstract

A natural α-1,6-glucan named BBWPW was identified from black beans. Cell viability assay showed that BBWPW inhibited the proliferation of different cancer cells, especially HeLa cells. Flow cytometry analysis indicated that BBWPW suppressed the HeLa cell cycle in the G2/M phase. Consistently, RT-PCR [...] Read more.

A natural α-1,6-glucan named BBWPW was identified from black beans. Cell viability assay showed that BBWPW inhibited the proliferation of different cancer cells, especially HeLa cells. Flow cytometry analysis indicated that BBWPW suppressed the HeLa cell cycle in the G2/M phase. Consistently, RT-PCR experiments displayed that BBWPW significantly impacts the expression of four marker genes related to the G2/M phase, including p21, CDK1, Cyclin B1, and Survivin. To explore the molecular mechanism of BBWPW to induce cell cycle arrest, a transcriptome-based target inference approach was utilized to predict the potential upstream pathways of BBWPW and it was found that the PI3K-Akt and MAPK signal pathways had the potential to mediate the effects of BBWPW on the cell cycle. Further experimental tests confirmed that BBWPW increased the expression of BAD and AKT and decreased the expression of mTOR and MKK3. These results suggested that BBWPW could regulate the PI3K-Akt and MAPK pathways to induce cell cycle arrest and ultimately inhibit the proliferation of HeLa cells, providing the potential of the black bean glucan to be a natural anticancer drug. Full article

(This article belongs to the Special Issue Natural Substances and Their Derivatives: In Search of New Structures, Activities and Applications)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
Determination of monosaccharide standards (A) and BBWPW (B). Full article ">Figure 2
NMR spectra of BBWPW. (A) 1H NMR, (B) 13C HMR, (C) DEPT 135, (D) 1H-1H COSY, (E) HSQC NMR, (F) HMBC and (G) NOESY spectra of BBWPW. Full article ">Figure 3
Effects of BBWPW on different cancer cells. BGC-823, HeLa, NCI-H460 and MCF-7 cancer cells were treated with different concentrations of BBWPW for 24 h, determined inhibition rate by MTT method (A) and observed the effect of BBWPW on HeLa cell morphology (B). n = 6. Full article ">Figure 4
Cell cycle arrest of HeLa cells induced by BBWPW was detected. After being treated with PBS (A) or 400 μg/mL BBWPW (B) for 24 h, the cell-cycle phase of HeLa cells was examined by flow cytometry with PI staining. (C) The cell cycle arrest rate in different phases. n = 3, (**) represent p < 0.01 compared with the PBS group. Full article ">Figure 5
The effects of BBWPW on mRNA expression of cell cycle-related genes in Hela cells. The mRNA expression of genes was examined after treatment of 400 µg/mL BBWPW for 6 h (A), 12 h (B) and 24 h (C). PBS as the control group. n = 3. (***) p < 0.001, (**) p < 0.01 and (*) p < 0.05 compared with the control group. Full article ">Figure 6
Analysis of RNA-seq data. (A) Hierarchical clustering of the samples by genes. In the heatmap, the 50 genes with the highest variance across samples were used. (B) Functional annotations of differential genes. Cell cycle pathways were indicated with red arrows. (C) Functional annotations of targets predicted by the transcriptome-based multi-scale network pharmacological platform. PI3k and MAPK pathways were indicated with red arrows. n = 2. Full article ">Figure 7
The mRNA expression of pathway-related genes in HeLa cells treated by BBWPW. The mRNA expression of genes was examined after treatment of 400 µg/mL BBWPW for 6 h (A), 12 h (B) and 24 h (C). PBS as the control group. n =3. (***) p < 0.001, (**) p < 0.01 and (*) p < 0.05 compared with the control group. Full article ">

Journal Menu

Journal Browser

Molecules, Volume 28, Issue 4 (February-2 2023) – 484 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI