JPH06100584A - New flavonoid glycoside - Google Patents

Abstract

PURPOSE:To obtain a new compound, capable of strongly suppressing the peroxidation of biomembrane lipids, excellent in antioxidizing activity, having ultrahigh safety and useful as an antioxidant to be added to a food, a drink and a cosmetic and further as a medicine due to its excellence in vivo antioxidizing activity. CONSTITUTION:The objective kaempferol-3-0-alpha-arabinoside-2''-gallate of the formula. Color and properties: yellow powder; molecular formula: C27H32O14, etc. This compound is obtained by extracting, e.g. a fresh leaf of a eucalyptus with a 50% aqueous acetone four times, then distilling away the acetone, subsequently separating the extract into liquid layers with ethyl acetate, adsorbing the resultant part soluble in the ethyl acetate on Amberlite XAD2(R), eluting the adsorbed substance with methanol, then separating and purifying the fraction eluted with 60% methanol according to the Sephadex(R) column chromatography, further separating and purifying the resultant substance according to high- performance liquid chromatography.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel flavonoid glycoside. INDUSTRIAL APPLICABILITY The novel flavonoid glycoside according to the present invention has an excellent antioxidant effect and is useful as a food / beverage product, a cosmetic product and a pharmaceutical product.

[0002]

BACKGROUND OF THE INVENTION Flavonoids are a group of compounds that are widely distributed in the plant kingdom and have been known for a long time. Although the functions of flavonoids in plants have not been fully elucidated, it is believed that these compounds are present in the epidermal cells of plants in relatively large amounts. It is considered to have an expression gene expression regulation, ATPase activity regulation, and an antioxidant effect by scavenging active oxygen and various radicals. Also, for animals, pharmacological actions such as recovery of capillary resistance, suppression of active oxygen formation in leukocytes, suppression of canceration, prevention of diabetic cataract and hypertension, elimination of active oxygen, suppression of lipid peroxidation reaction, etc. (Active oxygen, pages 342-347, 1989).

On the other hand, it has been conventionally known that plants such as eucalyptus have useful medicinal effects based on active oxygen scavenging action and suppression of lipid peroxidation reaction (future biological resources eucalyptus, Uchida Otsuru). Pp.146-153, 198
7).

[0004]

The present invention has been made for the purpose of newly separating a component having excellent medicinal effect from these plant-derived substances.

[0005]

The present invention has been made to achieve the above object, and the present inventors isolated and acquired flavonoid components for the purpose of searching for medicinal components of these plants. , I have been diligently researching. As a result, a novel flavonoid glycoside was discovered, its chemical structure was determined, and its antioxidant property was also confirmed, resulting in completion of the present invention.

Various glycosides in which a saccharide is bonded to a hydroxyl group of kaempferol, which is a type of flavonoid, have been reported, and kaempferol-3-arabinoside and kaempferol-3-rhamnoglucoside are known. ("Chemistry Dictionary 3" Kyoritsu Publishing (Sho 42-9-
10) p. 468). However, there is no report of a substance in which gallic acid is further bound to the bound sugar, which is the first of the present invention.

The novel flavonoid glycoside according to the present invention is
It has the physicochemical properties shown in Table 1 below.

[0008]

[Table 1]

From the above-mentioned physicochemical properties and other studies, the flavonoid glycoside according to the present invention shows that the kaempferol-3-O-α-arabinopyranoside-2 "-garrate (kaempferol 3-O) is present in the flavonoid glycoside according to the present invention. -Α-arab
inopyranoside-2 ″ -gallate)
It turned out to be Its chemical structural formula is shown in Chemical Formula 2 below.

[0010]

[Chemical 2]

The flavonoid glycoside according to the present invention is extracted from plants such as eucalyptus belonging to the genus Eucalyptus with water or an organic solvent (alcohol, ether, acetone, etc.), ethyl acetate and other organic solvents: water distribution, Separation of plant components such as various chromatography such as column chromatography,
Known methods used for extraction can be easily obtained individually or in combination. The crude extract can be further purified according to a conventional method, if necessary.

As the Eucalyptus tree, any plant belonging to the genus Eucalyptus can be used, and its site can also be leaves, stems, buds, flowers, xylem, bark, roots, etc.

The novel flavonoid glycoside ka according to the present invention
empferol 3-O-α-arabinopyr
Anoside-2 ″ -gallate has an action of suppressing the peroxidation of lipids in biological membranes, as is clear from the examples described later, and kaempferol and ga
The antioxidant activity is stronger than that of the llate, and it can be advantageously used not only in the field of in vivo antioxidant but also in the field of physiological activity related to the peroxidation reaction of biological membrane lipids.

Since the novel flavonoid glycoside represented by the chemical formula (I) according to the present invention has excellent antioxidant properties and is extremely safe, it can be used as an antioxidant in foods and drinks and cosmetics. It can also be used as various medicines by utilizing its excellent in vivo antioxidant activity.

When used as a drug, the compound according to the present invention is used as an active ingredient in the form of a solid, a semisolid or a liquid, to which a commonly used inorganic or organic carrier is added.
In addition to orally administered drugs, it is formulated into parenteral drugs such as external preparations.

Preparations for oral administration include tablets, pills, granules, soft and hard capsules, powders, fine granules, powders,
Examples thereof include emulsions, suspensions, syrups, pellets and elixirs. Formulations for parenteral administration include
Injection, drip, infusion, ointment, lotion, tonic,
Sprays, suspensions, oils, emulsions, suppositories and the like can be mentioned.
To formulate the active ingredient of the present invention, a conventional method may be followed, including a surfactant, an excipient, a coloring agent, a flavoring agent, a preservative,
Stabilizers, buffers, suspensions, isotonic agents and other commonly used auxiliaries are used as appropriate.

Taking Eucalyptus trees as an example, examples relating to the production of the compound according to the present invention and examples for measuring the peroxidation-inhibiting action of biological membrane lipids will be given below.

[0018]

Example 1 Production of Compound of the Present Invention 4 kg of fresh leaves of eucalyptus (1.8 kg as dry leaves) are extracted 4 times with 10 liters of 50% aqueous acetone, and the acetone is distilled off. After distilling off, use 3 ml of 500 ml of ethyl acetate.
The solution is separated 6 times, and the ethyl acetate-soluble portion is collected. This was packed in Amberlite XAD2 and eluted with methanol to obtain 60%
A methanol elution fraction is obtained. This is Sephadex LH
After separation and purification by -20 column chromatography and further separation and purification by high performance liquid chromatography, kaempferol 3-O-α-arazenopyranoside-2 ″ was obtained.
-Yield of 11 mg of gallate yellow powder (yield 0.000
6%). Its physicochemical properties are as described above, and its chemical structure is shown in chemical formula (I).

[0019]

Example 2 Measurement of peroxidation-inhibitory effect of biological membrane lipids

1) Method A rabbit red blood cell ghost membrane (2.5 mg protein / m) was placed in a test tube.
l) 0.9 ml and kaempferol 3-O-α-
arabinopyranoside-2 "-gall
Add 0.1 ml of ate's dimethylsulfoxide solution,
9 μl of tert-butyl hydroperoxide (10 mg / ml) dissolved in dimethyl sulfoxide was added to start the reaction. The reaction was carried out at 37 degrees Celsius for 30 minutes, and the reaction was stopped by adding 1.0 ml of 2M trichloroacetic acid. 2.0 ml of 0.67% thiobarbituric acid
Was added and reacted for 15 minutes in a boiling water bath, and the amount of thiobarbituric acid reaction positive substances such as malondialdehyde produced by this reaction was determined by measuring the absorbance at a wavelength of 535 nm. Based on this value, lipid peroxidation is 50
%, The concentration was determined, and the antioxidant activity was calculated for butylhydroxyanisole, which is a commercially available synthetic antioxidant.

2) Test Results A novel flavonoid glycoside, kaempferol, was used as an index with the concentration at which the peroxidation of rabbit erythrocyte membrane lipids was suppressed by 50%.
3-O-α-arabinopyranoside-
The antioxidant activity of 2 ″ -gallate is shown in Table 2 below.

[0022]

[Table 2]

As is clear from the above test results, the novel flavonoid glycoside kaempferol 3-O-α
-Arabinopyranoside-2 "-gal
The antioxidative activity of the plate is 2 in molar ratio as compared with the activity of butylhydroxyanisole which is a commercially available synthetic antioxidant.
It is about twice as powerful.

[0024]

The novel flavonoid glycoside k according to the present invention
ampferol 3-O-α-arabinopy
Ranoside-2 ″ -gallate has an activity (antioxidant activity) that strongly suppresses peroxidation of lipids in biological membranes, and is widely industrially used as a material for foods, cosmetics, pharmaceuticals, and the like.

Further, the chemical structure of the novel flavonoid glycoside has been clarified by the present invention. By chemically modifying or adding various modifications to the novel flavonoid glycoside, novel glycosides, novel aglycones, etc. It is also highly expected to obtain further compounds of

[Brief description of drawings]

1 shows fast atom bombardment mass spectra of compounds according to the invention.

FIG. 2 shows an ultraviolet absorption spectrum of the compound according to the present invention.

FIG. 3 shows a proton nuclear magnetic resonance spectrum of the compound according to the present invention.

FIG. 4 shows a carbon nuclear magnetic resonance spectrum of a compound according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshimasa Takahara 1-25-14 Kannondai, Tsukuba-shi, Ibaraki Tsukuba Research Area

Claims (3)

[Claims] 1. A novel flavonoid glycoside having the chemical formula (I) shown in the following chemical formula 1. [Chemical 1] 2. An in vivo antioxidant comprising the novel flavonoid glycoside according to claim 1 as an active ingredient. 3. The method for producing a novel flavonoid glycoside according to claim 1, which is collected from a tree of the genus Eucalyptus.