显齿蛇葡萄中二氢杨梅树皮素的抗氧化作用及其机制

目的 研究从显齿蛇葡萄植物中提取和纯化的二氢杨梅素(DMY)的抗氧化作用及其抗氧化机制。方法 用DPPH作稳定自由基测量DMY对其清除效果;用FeSO₄-依他酸引发亚酸油过氧化,用硫代巴比妥酸法测量DMY对过氧化产物的抑制率;用紫外法测DMY对Fe²⁺的络合作用。结果 DMY对稳定自由基DPPH的清除率高达73.3%～91.5%;DMY(0.01%～0.04%)可抑制亚油酸过氧化,其作用效果等同或优于TBHQ。DMY在FeSO₄-依他酸引发的亚油酸过氧化体系中的抗氧化机制为络合Fe²⁺,阻止由Fe²⁺引发的亚油酸过氧化。结论 DMY有较好的抗氧化效果,有可能成为一个很好的天然抗氧化剂。

Antioxidation properties and mechanism of action of dihydromyricetin from Ampelopsis grossedentata

AIM: To assess the antioxidative properties and the mechanism of action of dihydromyricetin (DMY) from Ampelopsis grossedentata. METHODS: The antioxidative properties of DMY were measured by scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and inhibiting lipid peroxidation induced by FeSO4-edetic acid in linoleic acid. The mechanism of antioxidative properties of DMY was tested by measuring the chelating activities of DMY for Fe2+ with ultraviolet spectrum (UV) method. RESULTS: The specific absorption of DPPH radical solution at 517 nm was reduced 73.3%-91.5% when DMY was added into the reaction solution in the concentration range from 0.01% to 0.04%. DMY was shown to greatly inhibit the increase of lipid peroxidation (LPO) values in linolei acid system catalyzed by FeSO4-edetic acid. The reaction rates (A532.min-1) of lipid peroxidation were 0.0021-0.0004 in the concentration range from 0.01% to 0.04% and the inhibition activities of DMY was found to be in a concentration-dependent manner. The mechanism of antioxidative properties of DMY was chelating Fe2+ in the Fe(2+)-dependent lipid peroxidation system. CONCLUSION: DMY showed great antioxidative effect and would be a good natural antioxidant.