Rebeccamycin and its Impurities

Rebeccamycin, an antitumor antibiotic, inhibits DNA topoisomerase I. Rebeccamycin appears to exert its primary antineoplastic effect by poisoning topoisomerase I and has negligible effect on protein kinase C and topoisomerase. Reference standards of Rebeccamycin API, and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.