丹参醌化合物结构特征与抗氧化活性

对双氢丹参醌I和丹参醌Ⅱ在油脂中的抗氧化作用及构效关系进行了量子化学研究。结果表明 ,抗氧化剂与油脂中碳中心自由基 (R· )复合成稳定自由基 (AH -R· ) ,可能是丹参醌抑制或阻止油脂氧化酸败的主要途径 ,双氢丹参醌I也可借助释放活泼H(本身转化成稳定自由基A· )有效清除R·。丹参醌分子本身的化学活性和对应的AH -R·与A·的稳定性对此类抗氧化作用有重要影响。AH -R·和A·中自旋集居分布 ,对比较抗氧化剂的相对活性可能是一个有价值的电子结构参数。

THE STRUCTURAL FEATURES AND ANTIOXIDATIVEACTIVITIES ON TANSHINONE COMPOUNDS I

The antioxidation effect of dihydrotanshinone I and tanshinone II on fat and the relationship between the structures and antioxidative activities of the two tanshinones were studied by quantum chemical calculation in this paper. The results show that the formation of stable radical AH-R· between the antioxidants and the carbon-centred free radical R·in fat may be a main mechanism of the antioxidation to retard lipid rancid, and dihydrotanshinone I can also react by donating a hydrogen atom to R·,becoming itself a stable radical A·. The chemical activities of tanshinone molecule and the stabilities of AH-R· and A· have important effects on the antioxidation. The distribution of spin populations in AH-R· and A·, specially the spin population of C atom at donating H, may be a valuable parameter of electric structure to compare the relative activity of antioxidants.