KR102066436B1 - Method for obtaining lignin degradation product using selective methylation - Google Patents

Abstract

Provided is a method for obtaining a lignin degradation product, comprising the steps of: selectively methylating a hydroxyl group of lignin; degrading methylated lignin using lignin degrading enzyme; and obtaining a degradation product containing an aromatic compound from the degradation step, wherein the selective methylation is to selectively methylate a functional group including a phenolic hydroxyl group (phenolic-OH) in the hydroxyl groups of the lignin.

Description

Method for obtaining lignin degradation product using selective methylation

Selectively methylating the hydroxyl group of lignin, decomposing the methylated lignin with a lignin degrading enzyme, and obtaining a degradation product comprising an aromatic compound from the decomposing, wherein the selective methylation is a hydroxyl group of lignin Disclosed is a method for obtaining a lignin decomposition product, wherein the functional group including a heavy phenolic hydroxyl group (Phenolic-OH) is selectively methylated.

In nature, billions of tons of lignin are biosynthesized every year, and tens of millions of tons of lignin are generated as by-products in pulp and paper production.

Lignin, together with cellulose and hemicellulose, is the major constituent of wood organic matter, which is the largest amount of organic matter accumulated on the earth, and is an important component in the secondary cell wall of plants. There is a characteristic that increases the content. Lignin also accounts for most of the aromatic carbon in the biosphere, which acts as a glue to polysaccharide filaments and fibers in living ducted plants, thereby maintaining the firmness and strength of the tissues, and transporting the plant's water. It is an important substance in that it also provides resistance to degradation of microorganisms (Monties and Fukushima, 2001). Lignin plays an important role in plant survival, while lignin degradation is important in the carbon source cycle (Crawford, 1981). In addition, since lignin is composed of a polymer such as an aromatic compound, a large amount of aromatic compound can be obtained by decomposition with a degrading enzyme.

Decomposition products produced by lignin degradation can be used in the paper and pulp industry, such as biopulping and biobleaching, and lignocellulosic can be converted into feed, fuel and other useful compounds. It can also be used to remove contaminants in wastewater or to treat toxic compounds.

Lignin is a very complex compound consisting of at least 12 different bonds, such as carbon-carbon (CC) and ether (COC) bonds, which are not normally degraded by enzymes because they require depolymerization by extracellular oxidative mechanisms. Although difficult, some filamentous fungi, especially white fungi, have been reported to have high lignin degradability.

Known lignin degrading enzymes produced during the degradation of lignin and contaminants by white fungi are lignin peroxidase (lip), manganese peroxidase (MnP), laccase (laccase), etc. (Tuor U, Winterhalter K, Fiechter A. 1995. Enzymes of white-rot fungi involved in lignin degradation and ecological determinants for wood decay.Journal of Biotechnology 41 (1): 1-17). However, there is a difference in function depending on the secreted enzyme.

Lignin peroxidase is composed of approximately 340 amino acids, heme protein (molecular weight of about 40kDa), non-phenol residues (non-phenol residues) of the lignin molecule in the presence of hydrogen peroxide (H ₂ O ₂ ) One electron is released from) to form a cationic radical, which radically oxidizes and depolymerizes lignin through an oxidation reaction. On the other hand, manganese peroxidases and laccases only function to oxidize the phenolic portion of lignin.

Manganese peroxidase, like lignin peroxidase, is a common peroxidase that degrades lignin. It is a glycoprotein containing heme protein and a degrading enzyme having a molecular weight of about 38,000 to 62,500 Da.

They are mostly released from fungi and break down lignin in nature. However, when lignin is decomposed using the above lignin degrading enzyme, there is a disadvantage that the degraded product is repolymerized so that the degradation efficiency is very low.In a large-scale process for biofuel production, it shows low stability and low activity. The application is known to be difficult because it requires a prosthetic group. In particular, lignin peroxidase, which shows the highest activity among the three degrading enzymes, is known to require hydrogen peroxide for its degradative activity, and the heme functional group of lignin peroxidase is easily attacked by hydrogen peroxide. The low stability that was received and destroyed and quickly deactivated acted as a barrier to commercial use.

Therefore, in order to obtain an aromatic compound by degrading lignin with a lignin degrading enzyme, a method for preventing repolymerization of the aromatic compound obtained by degrading lignin and at the same time maintaining a continuous active state of the lignin degrading enzyme is necessary.

Korean Patent No. 1443489, “Method for Hydrolyzing β-O- 4 Bonds of Lignin Using Solid Base Catalyst in Near-Critical Water to Produce Aromatic Compounds” (Published: 2014.02.07) Korean Patent No. 1627538, "Lignin Decomposition Catalyst, Alcohol and Organic Acids Production Method, Lignin Decomposition Product Production Method, Aromatic Hydrocarbon Decomposition Catalyst, Hydrogen Ion Method, and Porphyrin" (Published: 2011.05. 25)

An object of the present invention includes the step of selectively methylating the hydroxyl group of the lignin, decomposing the methylated lignin using a lignin degrading enzyme, and obtaining a degradation product comprising an aromatic compound from the decomposing step, Methylation is to provide a method for obtaining a lignin decomposition product, which is to selectively methylate a functional group containing a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of the lignin.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, another task that is not mentioned will be clearly understood by those skilled in the art from the following description.

According to one embodiment of the invention, the step of selective methylation of the hydroxyl group of the lignin; Digesting the methylated lignin with lignin degrading enzyme; And obtaining a decomposition product including an aromatic compound from the decomposition step, wherein the selective methylation is to selectively methylate a functional group including a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of lignin, A method for obtaining lignin degradation product is provided.

According to one side, the lignin degrading enzyme may be lignin peroxidase (Ligninperoxidase).

According to one side, the step of methylation may be by any one of dimethylsulfate (dimethylsulfate), dimethylcarbonate (Dimethylcarbonate).

According to one side, the selective methylation, the methyl group conversion rate of aliphatic hydroxyl (aliphatic-OH) may be less than 50%.

According to one side, the selective methylation may be to inhibit the repolymerization of the degraded lignin.

According to one side, the lignin, may be derived from any one of hardwood, coniferous and herbaceous wood.

According to one side, the aromatic compound, 3,4-dimethoxy benzoic acid (3,4-dimethoxy benzoic acid), 3,4,5-trimethoxy benzoic acid (3,4,5-trimethoxy benzoic acid), 3 , 4-dimethoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate ( methyl-3,4,5-trimethoxy benzoate) may be selected from the group consisting of.

According to one side, the lignin decomposition product may be 5 to 20% by weight of the lignin.

According to another embodiment of the invention, the step of selective methylation of the hydroxyl group of the lignin; Digesting the methylated lignin with lignin degrading enzyme; And obtaining a decomposition product including an aromatic compound from the decomposing step, wherein the selective methylation is carried out by a method of selectively methylating a functional group including a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of lignin. The resulting lignin degradation product is provided.

According to one side, the lignin decomposition product is 3,4-dimethoxy benzoic acid (3,4-dimethoxy benzoic acid), 3,4,5-trimethoxy benzoic acid (3,4,5-trimethoxy benzoic acid), 3 , 4-dimethoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate ( methyl-3,4,5-trimethoxy benzoate) may be any one or more selected from the group consisting of.

By using the method of the present invention, by selectively methylating the phenyl-hydroxy group of the lignin, the phenomenon of repolymerization of the decomposed compound can be alleviated. When the selective methylated lignin is decomposed by the lignin degrading enzyme, aromatics in high yield are obtained. The compound can be obtained, which is economical and environmentally friendly.

However, the effects of the present invention are not limited to the above-described effects, it should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a graph showing the methyl group conversion rate of the hardwood (poplar) -derived lignin hydroxyl group according to.
Figure 2 shows the content of the lignin hydroxyl group derived from conifers (pine).
3 is a graph showing the methyl group conversion rate of the conifer (pine) -derived lignin hydroxyl group.
4 is a table showing the content of the lignin hydroxyl group derived from the herbaceous (reed).
5 is a graph showing the methyl group conversion rate of the herbaceous (reed) free lignin hydroxyl group.
Figure 6 shows the conversion and degradation efficiency of the lignin dimer according to one embodiment.
Figure 7 shows the conversion and degradation efficiency of the lignin dimer according to another embodiment.
8 is a graph showing experimental results of identifying lignin degradation products through high performance liquid chromatography (HPLC).
9 shows five aromatic compounds identified by high performance liquid chromatography (HPLC).
Figure 10 shows the structure of the selective methylated lignin and the structure of the lignin degradation product obtained by digesting it.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. However, various changes may be made to the embodiments so that the scope of the patent application is not limited or limited by these embodiments. It is to be understood that all changes, equivalents, and substitutes for the embodiments are included in the scope of rights.

The terminology used herein is for the purpose of description and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In addition, in the description with reference to the accompanying drawings, the same components regardless of reference numerals will be given the same reference numerals and duplicate description thereof will be omitted. In the following description of the embodiment, when it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

According to one embodiment of the invention, the step of selective methylation of the hydroxyl group of the lignin; Digesting the methylated lignin with lignin degrading enzyme; And obtaining a decomposition product including an aromatic compound from the decomposition step, wherein the selective methylation is to selectively methylate a functional group including a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of lignin, A method for obtaining lignin degradation product is provided.

According to one side, the lignin degrading enzyme may be lignin peroxidase (Ligninperoxidase).

According to one side, the step of methylation may be by any one of dimethylsulfate (dimethylsulfate), dimethylcarbonate (Dimethylcarbonate).

According to one side, the selective methylation, the methyl group conversion rate of aliphatic hydroxyl (aliphatic-OH) may be less than 50%.

According to one side, the selective methylation may be to inhibit the repolymerization of the degraded lignin.

According to one side, the lignin, may be derived from any one of hardwood, coniferous and herbaceous wood.

According to one side, the aromatic compound, 3,4-dimethoxy benzoic acid (3,4-dimethoxy benzoic acid), 3,4,5-trimethoxy benzoic acid (3,4,5-trimethoxy benzoic acid), 3 , 4-dimethoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate ( methyl-3,4,5-trimethoxy benzoate) may be selected from the group consisting of.

According to one side, the lignin decomposition product may be 5 to 20% by weight of the lignin.

According to another embodiment of the invention, the step of selective methylation of the hydroxyl group of the lignin; Digesting the methylated lignin with lignin degrading enzyme; And obtaining a decomposition product including an aromatic compound from the decomposing step, wherein the selective methylation is carried out by a method of selectively methylating a functional group including a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of lignin. The resulting lignin degradation product is provided.

According to one side, the lignin decomposition product is 3,4-dimethoxy benzoic acid (3,4-dimethoxy benzoic acid), 3,4,5-trimethoxy benzoic acid (3,4,5-trimethoxy benzoic acid), 3 , 4-dimethoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate ( methyl-3,4,5-trimethoxy benzoate) may be any one or more selected from the group consisting of.

In a method for obtaining a lignin decomposition product using the present invention, a step of selectively methylating a lignin hydroxyl group is first performed.

Lignin has a phenolic hydroxyl group (Phenolic-OH) and aliphatic hydroxyl group (aliphatic-OH), and when the lignin is decomposed, it is repolymerized by the hydroxyl group of the degradation product to inhibit the activity of the degrading enzyme. According to the examples to be described later, it was confirmed that re-polymerization between the aromatic compounds by the phenol-based hydroxyl group (Phenolic-OH) contained in the aromatic compound, which is a decomposition product produced by the decomposition enzymes, resulting in poor decomposition efficiency. On the other hand, the aliphatic hydroxyl group (aliphatic-OH) was confirmed that the degradation efficiency of the lignin rather than methylation.

 Therefore, in order to suppress the repolymerization of the lignin decomposition product aromatic compound to increase the decomposition efficiency, the phenolic hydroxyl group (Phenolic-OH) is methylated with a relatively high probability, the aliphatic hydroxyl group (aliphatic-OH) is methylated with a low probability There is a need for selective methylation of lignin, which can cause.

The methylating agent used for the methylation can be used as long as it is known, and there is no restriction | limiting in particular.

However, general materials such as methyl bromide or methyl iodide are not suitable for the application of the present invention in that they have a characteristic of non-selectively donating methyl groups.

The principle of selective methylation is that the methylation is selectively possible using a substance that is a weakly basic catalyst and at the same time serves as a donor of the methyl functional group. Therefore, it is more preferable to use a methylating agent such as dimethylsulfate or dimethylcarbonate in the selective methylation of the present invention.

In addition, the selective methylation is preferably carried out under experimental conditions to implement the effect of inhibiting the repolymerization of the degraded lignin. In addition, the phenolic hydroxyl group (Phenolic-OH) is methylated with a high probability through the selective methylation, aliphatic hydroxyl group (aliphatic-OH) is preferably to be methylated with a low probability.

According to one embodiment, the methyl group conversion rate of the phenolic hydroxyl group (Phenolic-OH) is 50% or more, the methyl group conversion rate of the aliphatic hydroxyl group (aliphatic-OH) is preferably less than 50%.

More specifically, the methyl group conversion rate of the phenolic hydroxyl group (Phenolic-OH) is preferably 60% or more, and the methyl group conversion rate of the aliphatic hydroxyl group (aliphatic-OH) is less than 50%.

More specifically, the methyl group conversion rate of the phenolic hydroxyl group (Phenolic-OH) is preferably 70% or more, and the methyl group conversion rate of the aliphatic hydroxyl group (aliphatic-OH) is less than 40%.

Most preferably, a large amount of lignin decomposition products are obtained using selective methylated lignin having a methyl group conversion of at least 80% and a methyl group conversion of aliphatic hydroxyl at less than 30% of the phenolic hydroxyl group (Phenolic-OH). can do.

The dimethylsulfate and dimethyl carbonate have relatively little ability to donate methyl groups to aliphatic hydroxyl groups and easily dissociate protons. At the same time, the phenolic hydroxyl group (Phenolic-OH) has a characteristic of donating methyl groups more quickly. Due to this property, the methylation agent such as dimethylsulfate and dimethylcarbonate enables selective methylation with a high probability of phenolic hydroxyl group (Phenolic-OH) of lignin. In this case, controlling the degree of methylation is possible by controlling the content of the methylating agent. More specific methylation control will be described later through the examples.

If methylation is selectively methylated, it is digested using lignin degrading enzymes. In this case, the lignin degrading enzyme to be used may be a lignin peroxidase (Lignin peroxidase), manganese peroxidase (Mangan peroxidase) and laccase (laccase), etc. which are commonly used, and is not particularly limited, lignin Peroxidase is preferred.

Degradation of the selective methylated lignin with lignin degrading enzyme in the above-described manner may yield lignin degrading products.

Lignin degradation products obtained by digesting selective methylated lignin of the present invention are different from degradation products using selective unmethylated lignin.

Specifically, the lignin degradation product obtained by the method of the present invention includes an aromatic compound. In addition, the lignin decomposition product may be a known compound containing an aromatic monomer such as vanillin, syringaldehyde, p-hydroxybenzaldehyde, vanyl acid, syringe acid, and the like.

More specifically, the aromatic compound is 3,4-dimethoxy benzoic acid, 3,4,5-trimethoxy benzoic acid, 3,4-dimethoxy benzoic acid, 4-dimethoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate (methyl At least one selected from the group consisting of -3,4,5-trimethoxy benzoate).

Figure 10 shows the structure of the selective methylated lignin and the structure of the lignin decomposition products obtained by decomposing the same as described above.

Referring to FIG. 10, the synthesized lignin dimers were divided into (a) of FIG. 10 using unmethylated lignin and (b) of methylated lignin, respectively, according to the presence or absence of methylation. As shown in (b), the lignin was not obtained by lignin, but the selective methylated lignin was obtained as a degradation product.

A more detailed description will be made later through the following examples.

Example 1.

The methylation reaction of hardwood (poplar) -derived lignin (dimer) using 0.5 M sodium hydroxide (NaOH) and various concentrations of dimethylsulfate was performed.

At this time, the reason for varying the concentration of dimethylsulfate (dimethylsulfate) used as a methylating agent was to control the degree of methylation of lignin. Before adding the methylating agent, the phenolic hydroxyl group (Phenolic-OH) present in the synthesized lignin dimer was quantified. Thereafter, dimethylsulfate (dimethylsulfate) was added in 1.6, 3.3, 5, and 16-fold molar equivalents of the phenol-based hydroxyl group (Phenolic-OH) to proceed with methylation. The methylation reaction was carried out at 45 ° C. for 3 hours. After the reaction was completed, the methylated mixture (compound) was extracted with ethyl acetate, and the ethyl acetate layer was evaporated by purging with nitrogen gas. Thereafter, the remaining samples were quantified by the content of hydroxyl groups and the efficiency of methylation reaction using 31P-NMR and GC / MS analysis.

As a result, as shown in FIG. 1, about 90% of the phenolic hydroxyl group (Phenolic-OH) is converted to methylation, whereas only about 40% of the aliphatic hydroxyl group (Aliphatic-OH) is converted. It was confirmed that methylation did not proceed. Similar results were obtained when the same experiment was conducted with coniferous (pine) lignin and herbaceous (reed) -derived lignin.

Figure 2 shows the results of the selective methylation of pine-derived lignin by the same method as described above. 2, the lignin type (Lignin type) on the left side of the table shows that the methylation reaction was carried out by adding multiple dimethylsulfate (dimethylsulfate) to methylated pine derived lignin (Pine MWL). As shown, it can be seen that the phenolic hydroxyl group (Phenolic-OH) is methylated with a high probability.

3 is a graph showing the methylation ratio of phenolic hydroxyl group (Phenolic-OH) and aliphatic hydroxyl group (Aliphatic-OH). As shown, as the amount of dimethylsulfate is increased, the hydroxyl group content of the phenolic hydroxyl group (Phenolic-OH) is decreasing, while the hydroxyl group content of the aliphatic hydroxyl group (aliphatic-OH) is significantly changed. There was no. Therefore, it was confirmed that selective methylation was possible by adjusting the amount of dimethylsulfate.

As a result of the methylation reaction of the lignin derived from the herbaceous (reed) in the same manner as shown above similar to the results of Figure 2 and 3 experiment. (Figures 4 and 5)

That is, using the method of the present invention, the phenolic hydroxyl group (Phenolic-OH) can be subjected to selective methylation with a relatively high probability, about 60% in the case of aliphatic hydroxyl group (aliphatic-OH), specifically It can be seen that at least 50% can remain unmethylated.

Example 2.

When phenolic hydroxyl group (Phenolic-OH) and aliphatic hydroxyl group (aliphatic-OH) are methylated, a total of 10 lignin-binding forms (beta-O-) are used to examine the effects on the lignin-degrading activity of Lignin peroxidase. 4) A dimer having a bond was synthesized. 10 dimers having different binding patterns are represented by the following Chemical Formula 1.

Ten lignin dimers synthesized in the above structure and the number of phenolic hydroxyl groups (Phenolic-OH) and aliphatic hydroxyl groups (aliphatic-OH) of each dimer are shown in Table 1 below.

Lignin
Dimer Number of Phenolic Hydroxyl (Phenolic-OH) Number of aliphatic hydroxyls (aliphatic-OH) 1a One 2 1b 0 2 1c 0 One 1d 0 One 1e 0 0 2a One 2 2b 0 2 2c 0 One 2d 0 One 2e 0 0

Example 3.

When the lignin dimer prepared in Example 2 was decomposed using lignin peroxidase, in the case of 1b, 1c, and 1d without phenolic hydroxyl group (Phenolic-OH), an aromatic compound could be obtained as a degradation product. . On the other hand, when the methylation reaction does not proceed and there exists a phenolic hydroxyl group (Phenolic-OH) as shown in 1a, it was not possible to obtain an aromatic compound as a decomposition product. However, in the case of 1e in which all aliphatic hydroxyl groups (aliphatic-OH) are methylated, although there is no phenolic hydroxyl group (Phenolic-OH), an aromatic compound that is a decomposition product could not be obtained. Experimental results show that the phenolic hydroxyl group (Phenolic-OH) inhibits the repolymerization of the degradation products and the activity of the degradation enzyme, whereas the aliphatic hydroxyl group (aliphatic-OH) recognizes the compound repolymerization of the degradation enzyme, It could be expected to play a role in inducing such repolymerized bond degradation. This trend was confirmed that the same can be applied to other types of lignin dimers can be applied to the actual decomposition of lignin. (FIGS. 6 and 7)

Example 4.

In order to obtain an aromatic monomer compound, as a result of the methylation reaction in Example 1, the obtained hardwood (poplar) -derived lignin was depolymerized with lignin degrading enzyme.

The depolymerization was carried out in BR buffer 0.1M, pH 3.0. Methylated lignin and lignin degrading enzyme were prepared at working concentrations of 0.4 mg / ml and 1 μM, respectively. The reaction was started by adding H ₂ O ₂ at a feed rate of 50 μM / 15 minutes. At the time of sampling, the reaction was stopped by adding 1 μl of 10 M NaOH to 200 μl of sampled sample reaction solution to prepare the required sample. The prepared sample was filtered through a PTFE hydrophilic 0.2 μm membrane filter to remove solids.

To confirm the depolymerization result, the filtered sample was injected and subjected to high performance liquid chromatography (HPLC).

HPLC reactions were performed by injecting the samples into a reversed phase Eclipse XDB-C18 column (4.6 × 150 mm, 5 μm, Agilent) using an Agilent 1200 HPLC system. The results were compared with standard libraries based on the ultraviolet absorption spectra of the obtained samples, and the reaction was quantified based on the linear external standard curve (R> 0.95) of each compound.

Over time, HPLC peaks corresponding to a total of five aromatic monomer compounds were observed, and the area of these peaks was observed to increase proportionally with time. (Figure 8)

To gradient the material contained in the sample, centrifuged for 15 minutes at a flow rate of 1.5 ml / min under a column temperature of 30 ° C. using 0.1% aqueous trifluoro acetic acid and methanol-acetonitrile as solvents. The compound contained was isolated.

The compound contained in the sample was identified as five aromatic monomers. The aromatic monomers were 3,4-dimethoxy benzoic acid, 3,4,5-trimethoxy benzoic acid, 3,4-dimethoxy benzaldehyde, 3,4,5-trimethoxy benzaldehyde, methyl-3,4,5-trimethoxy benzoate, respectively. . Considering the sum of these aromatic monomer compounds, it can be seen that about 10.7% of the total lignin weight was produced by decomposing the monomer aromatic compounds (FIG. 9).

In the graphs shown in FIGS. 8 and 9, met-MWL (metyl-milled wood lignin) refers to selective methylated lignin according to one embodiment of the present invention.

 Although the embodiments have been described with reference to the accompanying drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the techniques described may be performed in a different order than the described method, and / or the components described may be combined or combined in a different form than the described method, or replaced or substituted by other components or equivalents. Appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the following claims.

Claims (10)

Selectively methylating the hydroxyl group of lignin;
Degrading the methylated lignin using Ligninperoxidase; And
Obtaining a decomposition product including an aromatic compound from the decomposition step;
Including,
The selective methylation is to selectively methylate a functional group including a phenolic hydroxyl group (Phenolic-OH) in the hydroxyl group of the lignin,
The aromatic compound is 3,4-dimethoxy benzoic acid, 3,4,5-trimethoxy benzoic acid, 3,4-dimethoxy Benzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxybenzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate (methyl-3,4 , 5-trimethoxy benzoate) is selected from the group consisting of
Method for obtaining lignin degradation product using an enzyme. delete The method of claim 1,
The methylation step is dimethylsulfate (dimethylsulfate), dimethyl carbonate (Dimethylcarbonate) by any one of, lignin decomposition product obtained by using an enzyme method. The method of claim 1,
The selective methylation is a method of obtaining a lignin decomposition product using an enzyme, wherein the methyl group conversion rate of aliphatic hydroxyl group (aliphatic-OH) is less than 50%. The method of claim 1,
The selective methylation is to inhibit the repolymerization of the degraded lignin, a method for obtaining a lignin decomposition product using an enzyme. The method of claim 1,
The lignin is derived from any one of hardwoods, conifers and herbaceous wood, the method for obtaining lignin degradation products using enzymes. delete The method of claim 1,
The lignin decomposition product is 5 to 20% by weight of the lignin, a method for obtaining a lignin decomposition product using an enzyme. Lignin degradation products obtained by the method of claim 1,
The lignin decomposition products, 3,4-dimethoxy benzoic acid, 3,4,5-trimethoxy benzoic acid, 3,4-dimethic Methoxybenzaldehyde (3,4-dimethoxy benzaldehyde), 3,4,5-trimethoxy benzaldehyde (3,4,5-trimethoxy benzaldehyde), methyl-3,4,5-trimethoxybenzoate (methyl-3, 4,5-trimethoxy benzoate) lignin decomposition products comprising any one or more selected from the group consisting of. delete

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