The syntheses of fourteen unusual o-carboxamido stilbenes by the Heck protocol revealed surprising complexity related to intriguing substituent effects with mechanistic implications. The unexpected cytotoxic and chemopreventive properties also seem to be substituent dependent. For example, although stilbene 15d (with a 4-methoxy substituent) showed cytotoxicity on HT29 colon cancer cells with an IC50 of 4.9 μM, the 3,4-dimethoxy derivative (15c) is inactive. It is interesting to observe that the 3,5-dimethoxy derivative (15e) showed remarkable chemopreventive activity in WRL-68 fetal hepatocytes, surpassing the gold standard, resveratrol. The resveratrol concentration needed to be 5 times higher than that of 15e to produce comparable elevation of NQO1.
通过 Heck 反应协议合成的十四种不寻常的邻羧酰胺基
二苯乙烯揭示了与具有机制含义的引人注目的取代基效应相关的惊人复杂性。意外的细胞毒性和
化学预防特性似乎也依赖于取代基。例如,尽管具有 4-甲氧基取代基的
二苯乙烯 15d 对 HT29 结肠癌细胞表现出细胞毒性,其 IC50 为 4.9 μM,但 3,4-二甲氧基衍
生物(15c)无活性。有趣的是,观察到 3,5-二甲氧基衍
生物(15e)在 WRL-68 胎肝细胞中表现出显著的
化学预防活性,超过了黄
金标准,
白藜芦醇。需要比 15e 高 5 倍的
白藜芦醇浓度才能产生可比较的 NQO1 升高。