Rebeccamycin

Rebeccamycin is a weak topoisomerase I inhibitor isolated from Streptomyces sp. It is structurally similar to staurosporine, but does not show any inhibitory activity against protein kinases. It shows significant antitumor properties in vitro (IC50=480nM against mouse B16 melanoma cells and IC50=500nM against P388 leukemia cells).