Microbial transformations of natural antitumour agents. Part 5. The structure of a novel vindoline dimer produced by Streptomyces griseus
Abstract
Microbial transformation experiments have been conducted with the alkaloid vindoline. Streptomyces griseus(UI 1158) gave good yields of dihydrovindoline ether (2a), and a novel, dimeric vindoline metabolite (4) whose structure was determined by 13C and 1H n.m.r. and high resolution mass spectrometry. It consists of two dihydrovindoline ether (2a) moieties joined by a carbon–carbon bond which is probably formed by means of an enamine coupling reaction.