| abstract |
Novel maytansinoids of the formula: <IMAGE> wherein Y is H or Cl, and R is C2-15alkyl, phenyl-C1-4alkyl, pyridyl-C1-4alkyl, imidazolyl-C1-4alkyl, indolyl-C1-4alkyl, furyl-C1-4alkyl or thienyl-C1-4alkyl, said R group being substituted by hydroxyl, halogen or C1-5alkanoyloxy at its alpha - and/or beta -position, have antimitotic, antitumor and antimicrobial activities. |