A process for preparing maytansinol, maytanacin and / or maytansinolpropionat

摘要

Maytansinol, maytanacin and/or maytansinol propionate are prepared by culturing a microorganism belonging to the genus Nocardia, which is able to produce maytansinol, maytanacin and/or maytansinol propionate, with concentration of maytansinol, maytanacin and/or maytansinol propionate, and isolating it from the culture broth. These compounds are useful antitumour agents, i.e. useful cytostatics.