A series of new ecteinascidin pentacyclic-derived compounds bearing aryl carboxylic amide side chains at C-22 have been designed and synthesized. The cytotoxicity evaluation confirmed their potent antitumor activity by use of eight different cell lines. Studies on the structure-activity relationship of them showed that the chemical structure of C-22 pendants have great effects on the tumor-killing activity. Notably, Compounds 6, 7 and 8 with benzo[b]thiophene-2-carboxamide pendants exhibited excellent broad-spectrum antitumor activity with the low IC₅₀ values of 10⁻⁷ M.

中文翻译：

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简化的ecteinascidin五环骨架衍生物作为抗癌剂的合成及细胞毒性筛选

设计并合成了一系列在C-22上带有芳基羧基酰胺侧链的新的十碳胞苷五环衍生物。细胞毒性评估通过使用八种不同的细胞系证实了其有效的抗肿瘤活性。对它们的构效关系的研究表明，C-22侧基的化学结构对杀肿瘤活性有很大的影响。值得注意的是，化合物6，7和8与苯并[ b ]噻吩-2-甲酰胺吊坠表现出优异的广谱的抗肿瘤活性与低IC _50个的10个值^-7  M.