Indolocarbazole protein kinase C inhibitors from rebeccamycin

Structural modifications were carried out on rebeccamycin, an antitumour antibiotic, to obtain analogues. The inhibitory potencies of these analogues against protein kinase C are compared. The method described represents an alternative route to the staurosporin aglycone, a potent protein kinase C inhibitor. Structural modifications of Rebeccamycin, an antitumor antibiotic without activity against protein kinase C, are described. The inhibitory potencies of the derivatives against this enzyme are presented.