Plant antitumor agents. 29. Synthesis and biological activity of ring D and ring E modified analogs of camptothecin

AW Nicholas, MC Wani, G Manikumar…

Index: Nicholas; Wani; Manikumar; Wall; Kohn; Pommier Journal of Medicinal Chemistry, 1990 , vol. 33, # 3 p. 972 - 978

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Citation Number: 86

Abstract

The total synthesis of the pentacyclic camptothecin analogues 3 and 4 in 11 steps from p- tolualdehyde is described. The overall shape of compound 3 is the same as that of potent, naturally occurring camptothecin (la). Despite the near spatial identity of 3 and lb (racemic,(BORS)-camptothecin) from a three-dimensional standpoint, the 9KB and 9PS cytotoxicity assays indicate at least a 40-60-fold decrease in activity of 3 compared to that ...