阅读说明：本技术 一种3′，4′，5′，6，7，8-六羟基异黄酮的合成方法及其在抗氧化方面的应用 (Synthesis method of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone and application thereof in antioxidation ) 是由 景临林 张冬梅 马慧萍 邵瑾 赵彤 于 2020-06-08 设计创作，主要内容包括：本发明公开了3′,4′,5′,6,7,8-六羟基异黄酮的合成方法,该方法包括以下步骤：(1)大豆苷元与溴素在乙醇介质及80～90℃下反应得到3′,5′,6,8-四溴-4′,7-二羟基异黄酮；(2)步骤(1)的产物与甲基化试剂反应得到3′,5′,6,8-四溴-4′,7-二甲氧基异黄酮；(3)步骤(2)的产物在亚铜盐作用下与甲醇钠反应,得到3′,4′,5′,6,7,8-六甲氧基异黄酮；(4)3′,4′,5′,6,7,8-六甲氧基异黄酮脱甲基,得到所述的3′,4′,5′,6,7,8-六羟基异黄酮。该化合物具有优异的抗氧化活性。本发明起始原料来源丰富,反应条件温和,步骤短、产率高,易于工业化生产。(The invention discloses a method for synthesizing 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone, which comprises the following steps: (1) reacting daidzein and bromine in an ethanol medium at 80-90 ℃ to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone; (2) reacting the product obtained in the step (1) with a methylating agent to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxy isoflavone; (3) reacting the product obtained in the step (2) with sodium methoxide under the action of cuprous salt to obtain 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone; (4) demethylating the 3 ', 4', 5 ', 6, 7, 8-hexamethoxyisoflavone to produce said 3', 4 ', 5', 6, 7, 8-hexahydroxyisoflavone. The compound has excellent antioxidant activity. The method has the advantages of rich source of the initial raw materials, mild reaction conditions, short steps, high yield and easy industrial production.)

1. A method for synthesizing 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone comprises the following steps:

(1) reacting daidzein and bromine in an ethanol medium at 80-90 ℃ to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone, wherein the molar ratio of daidzein to bromine is 1: 5-7;

(2)3 ', 5', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone reacts with a methylating agent to obtain 3', 5 ', 6, 8-tetrabromo-4', 7-dimethoxyisoflavone;

(3) reacting 3 ', 5', 6, 8-tetrabromo-4 ', 7-dimethoxy isoflavone with sodium methoxide under the action of cuprous salt to obtain 3', 4 ', 5', 6, 7, 8-hexamethoxy isoflavone;

(4) demethylating the 3 ', 4', 5 ', 6, 7, 8-hexamethoxyisoflavone to produce said 3', 4 ', 5', 6, 7, 8-hexahydroxyisoflavone.

2. The method of synthesis according to claim 1, characterized in that: the methylating agent is dimethyl sulfate or dimethyl carbonate.

3. The method of synthesis according to claim 1, characterized in that: the cuprous salt is cuprous bromide, cuprous iodide and/or cuprous chloride.

4. The method of synthesis according to claim 1, characterized in that: the specific process of the step (2) comprises the following steps: mixing 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone, potassium carbonate and a methylating agent in an organic solvent for reaction to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone, wherein the molar ratio of the 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone to the potassium carbonate to the methylating agent is 1: 2-3, and the reaction temperature is 60-70 ℃.

5. The method of synthesis according to claim 1, characterized in that: the specific process of the step (3) comprises the steps of mixing 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone with an organic solvent, heating to 110-130 ℃, adding cuprous salt and excessive sodium methoxide, and reacting to obtain 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone, wherein the molar ratio of the 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone to the cuprous salt is 1: 4-6.

6. The method of synthesis according to claim 1, characterized in that: the specific process of the step (4) comprises the following steps: suspending aluminum chloride in an organic solvent, cooling to 0-8 ℃, slowly dropwise adding dimethyl sulfide, uniformly mixing, adding 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone, heating, and reacting at 20-30 ℃ to obtain 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone, wherein the molar ratio of the aluminum chloride to the dimethyl sulfide to the 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone is 15-20: 1.

7. The synthesis method according to any one of claims 4 to 6, wherein: the organic solvent is acetone, dichloromethane or N, N-dimethylformamide.

8. A polyhydroxy isoflavone characterized by: the chemical structural formula of the polyhydroxy isoflavone is as follows:

the chemical name is 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone.

9. Use of polyhydroxyisoflavones according to claim 8, characterized in that the polyhydroxyisoflavones are used for the preparation of anti-oxidant medicaments.

Technical Field

The invention belongs to the field of drug synthesis, and particularly relates to a synthesis method of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone and application thereof in antioxidation.

Background

Isoflavones are secondary metabolites of plants and have a wide range of physiological activities such as anti-inflammatory, antiviral, anti-tumor, anti-diabetic, anti-radiation, anti-ischemia-reperfusion injury, neuroprotection, etc., and these beneficial pharmacological effects are mostly attributed to their excellent antioxidant activities, which can prevent oxidative damage by inhibiting and scavenging free radicals and reactive oxygen species (nat. prod. rep, 2019, 36 (8): 1156-1195). The study indicated that: the hydroxyl substituent in the isoflavone structure is an active group for scavenging free radicals, and the number, substitution position and substitution form of the hydroxyl group have important effects on the activity (Int J Mol Sci, 2015, 16 (6): 12891-12906).

The structural formula of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone is as follows:

the molecular structure contains 6 phenolic hydroxyl groups, and theoretically, the compound has excellent antioxidant activity, but the compound is a new-structure compound and does not exist in natural products, and no report on a preparation method and antioxidant activity exists at present.

Disclosure of Invention

The present invention aims at providing one kind of polyhydroxy isoflavone with excellent antioxidant activity and its preparation process.

In order to achieve the purpose, the invention adopts the following technical scheme:

a polyhydroxy isoflavone having the following chemical structure:

the chemical name is 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone.

A method for synthesizing 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone comprises the following steps:

(1) reacting daidzein and bromine in an ethanol medium at 80-90 ℃ to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone, wherein the molar ratio of daidzein to bromine is 1: 5-7;

(2)3 ', 5', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone reacts with a methylating agent to obtain 3', 5 ', 6, 8-tetrabromo-4', 7-dimethoxyisoflavone;

(3) reacting 3 ', 5', 6, 8-tetrabromo-4 ', 7-dimethoxy isoflavone with sodium methoxide under the action of cuprous salt to obtain 3', 4 ', 5', 6, 7, 8-hexamethoxy isoflavone;

(4) demethylating the 3 ', 4', 5 ', 6, 7, 8-hexamethoxyisoflavone to produce said 3', 4 ', 5', 6, 7, 8-hexahydroxyisoflavone.

Preferably, the methylating agent is dimethyl sulfate or dimethyl carbonate.

Preferably, the cuprous salt is cuprous bromide, cuprous iodide and/or cuprous chloride.

Preferably, the specific process of step (2) comprises: mixing 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone, potassium carbonate and a methylating agent in an organic solvent for reaction to obtain 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone, wherein the molar ratio of the 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dihydroxyisoflavone to the potassium carbonate to the methylating agent is 1: 2-3, and the reaction temperature is 60-70 ℃.

Preferably, the specific process of step (3) comprises: mixing 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone with an organic solvent, heating to 110-130 ℃, adding cuprous salt and excessive sodium methoxide while stirring, and reacting to obtain 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone, wherein the molar ratio of the 3 ', 5 ', 6, 8-tetrabromo-4 ', 7-dimethoxyisoflavone to the cuprous salt is 1: 4-6.

Preferably, the specific process of step (4) comprises: suspending aluminum chloride in an organic solvent, cooling to 0-8 ℃, slowly dropwise adding dimethyl sulfide, uniformly mixing, adding 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone, heating, and reacting at 20-30 ℃ to obtain 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone, wherein the molar ratio of the aluminum chloride to the dimethyl sulfide to the 3 ', 4 ', 5 ', 6, 7, 8-hexamethoxyisoflavone is 15-20: 1.

Preferably, the organic solvent is acetone, dichloromethane or N, N-dimethylformamide.

The invention takes daidzein with rich sources as a starting material, and obtains 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone by four steps of bromination, methylation, methoxylation and demethylation, wherein the total yield is more than 60 percent (calculated by daidzein). The synthetic method has the advantages of mild reaction conditions, high yield and easy industrial production. The purity of the product is more than 99.0 percent monitored by UPLC, and the product can be used for pharmacological activity research.

To elucidate the antioxidant activity of the compounds, the present invention utilized DPPH.radical scavenging experiments, superoxide anion (O)₂ ^-·) The antioxidant activity of the Nitric Oxide (NO) scavenging test and the scavenging test is investigated by three methods, and the results show that: 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone pair DPPH, O₂ ^-·And IC of NO₅₀Values are 0.831mmol/L, 0.034mmol/L and 0.122mmol/L, respectively, and positive drug V_CFor DPPH, O₂ ^-·IC of and NO₅₀The values were 1.675mmol/L, 0.482mmol/L and 1.641mmol/L, respectively. The above results show that: the scavenging activity of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxy isoflavone to three free radicals is far greater than V_CHas excellent antioxidant activity.

Drawings

FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone.

FIG. 2 is a nuclear magnetic resonance carbon spectrum of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone.

FIG. 3 is a high resolution mass spectrum of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone.

FIG. 4 is a UPLC chromatogram of 3 ', 4 ', 5 ', 6, 7, 8-hexahydroxyisoflavone.

Detailed Description

The present invention will be described in further detail with reference to examples.