Maytansinoids, pharmaceutical compositions thereof and method of use thereof

摘要

Novel maytansinoid compounds of the formula: <IMAGE> wherein X is H or Cl, R1 is an alkyl group of 2 to 4 carbon atoms and R2 is a lower alkyl group or an unsubstituted or substituted phenyl or aralkyl group, have antimitotic, antitumor and antimicrobial activities.