Plant antitumor agents. 29. Synthesis and biological activity of ring D and ring E modified analogs of camptothecin
作者:Allan W. Nicholas、Mansukh C. Wani、Govindarajan Manikumar、Monroe E. Wall、Kurt W. Kohn、Yves Pommier
DOI:10.1021/jm00165a014
日期:1990.3
activity for 3 and no activity for 4. It is evident that the pyridone ring D is essential for antitumor activity. Three E ring modified analogues of camptothecin, 2d-f, are described in which the net change is replacement of O by N in ring E. Compared to (20S)-camptothecin (1a) or (20RS)-camptothecin (1b), the ring E modified analogues 2d-f display little or no cytotoxic activity, greatly reduced effect
描述了由对甲苯甲醛分11个步骤的五环喜树碱类似物3和4的全合成。化合物3的整体形状与有效的天然喜树碱(1a)相同。尽管从三维的角度来看3和1b(外消旋,(20RS)-喜树碱)具有近乎空间的同一性,但9KB和9PS细胞毒性试验表明3的活性至少比1b降低了40-60倍,且异构体4不活泼。同样,对拓扑异构酶I活性的抑制研究表明,对3的活性很小,对4的活性却没有。显然,吡啶酮环D对于抗肿瘤活性是必不可少的。描述了喜树碱的三个E环修饰类似物2d-f,其中的净变化是E环中的O被N取代。