二氢杨梅素乙酰化衍生物的合成及其抗氧化活性研究

Synthesis and Antioxidant Activities of Dihydromyricetin Acetyl Derivatives

以二氢杨梅素(6)为原料,在不同的催化条件下与不同的酰化试剂进行乙酰化反应制备得3,5,7,3',4',5'-六乙酰基二氢杨梅素(1)、3,3',4',5'-四乙酰基二氢杨梅素(2)、3,7,3',4',5'-五乙酰基二氢杨梅素(3)、3-乙酰基二氢杨梅素(4)和二氢杨梅素丙酮加成物(5),且用MS、1H NMR和13C NMR确证结构。通过测试目标化合物对羟自由基(·OH)和超氧阴离子(O2-·)的清除作用,考察二氢杨梅素乙酰化衍生物的抗氧化活性,结果显示抗氧化能力大小顺序为6>4>5>2>3>1。

3,5,7,3＇,4＇,5＇-Hexaacetyldihydromyricetin（1）, 3,3＇,4＇,5＇-tetraacetyldihydromyricetin （2）, 3,7,3＇,4＇,5＇- pentaacetyldihydromyricetin （3）, 3-acetyldihydromyricetin （4） and acetone adduct of dihydromyricetin （5） were synthesized from dihydromyricetin （6） with different acylating reagents under different catalytic conditions. Their structures were confirmed through MS, ^1H NMR and ^13C NMR. Their antioxidant activities were evaluated by the clearance effect to hydroxyl radical and superoxide anion. The results showed that the antioxidant activities of these compounds in descending order were 6〉4〉5〉2〉3〉1.