Significant enhancement in radical-scavenging activity of curcuminoids conferred by acetoxy substituent at the central methylene carbon
作者:Mi Kyoung Kim、Wooseong Jeong、Jihoon Kang、Youhoon Chong
DOI:10.1016/j.bmc.2011.04.055
日期:2011.6
chain-propagating peroxyl radicals. Curcumin has a unique structure with phenolic hydroxyl group as well as β-diketone moiety in the same molecule, both of which are able to donate electrons to free radicals. However, due to the reactivity toward molecular oxygen, the carbon-centered radical derived from β-diketone moiety do not serve as radical-trapping antioxidants. In this study, we reasoned that stabilization
为了使化合物成为捕获自由基的抗氧化剂,抗氧化剂衍生的自由基必须对分子氧足够惰性,因为这会产生有害的链增长性过氧自由基。姜黄素具有独特的结构,在同一分子中具有酚羟基以及β-二酮部分,两者都能够将电子提供给自由基。然而,由于对分子氧的反应性,源自β-二酮部分的以碳为中心的自由基不能用作捕获自由基的抗氧化剂。在这项研究中,我们认为通过用吸电子基团取代来稳定以碳为中心的自由基会增强所得姜黄素清除自由基的抗氧化活性。因此,各种取代基(甲基,烯丙基,甲氧基,黄原酸酯,包括广谱的极性取代基作用的乙酰氧基和乙酰氧基)被引入到酚类和非酚类姜黄素的中心亚甲基位置。在存在游离酚羟基的情况下,亚甲基取代基对姜黄素的抗氧化活性没有显着影响(欧洲共同体50 = 23.2-30.3μM)与异常的乙酰氧基取代的衍生物(EC 50 = 8.7μM),其显示出比姜黄素更有效的活性(EC 50 = 22.6μM)。但是,