Cryptophycin: A New Antimicrotubule Agent Active against Drug-resistant Cells

Abstract Cryptophycin is a cytotoxic dioxadiazacyclohexadecenetetrone isolated from cyanobacteria of the genus Nostoc . Incubation of L1210 leukemia cells with cryptophycin resulted in dose-dependent inhibition of cell proliferation in parallel with increases in the percentage of cells in mitosis (half-maximal effects at Vinca alkaloids. This property may confer an advantage to cryptophycin in the chemotherapy of drug-resistant tumors.