A series of 3-demethoxycarbonyl-3-amide methyl anhydrovinblastine derivatives (5b− 24b) was designed, synthesized, and evaluated for their proliferation inhibition activities against two tumor cell lines (A549 and HeLa). Most of the amide anhydrovinblastine derivatives exhibited potent cytotoxicity, with the size of the introduced substituents being the foremost factor in determining the resultant cytotoxic activity. Test results in vivo against sarcoma ...