Marmycins A and B,Cytotoxic Pentacyclic C-Glycosides from a Marine Sediment-Derived Actinomycete Related to the Genus Streptomyces

摘要

Two new cytotoxic quinones of the angucycline class,marmycins A and B(1,2),were isolated from the culture broth of a marine sediment-derived actinomycete related to the genus Streptomyces.The gross structures and absolute configurations of both compounds were determined by spectroscopic and crystallographic methods.Marmycin A(1)displayed significant cytotoxicity against several cancer cell lines,some at nanomolar concentrations;while compound 2,a chloro analogue of 1,was less potent.For marmycin A(1),tumor cell cytotoxicity appeared to coincide with induction of modest apoptosis and arrest in the G1 phase of the cell cycle.