2002 Volume 55 Issue 4 Pages 355-362
During the course of our screening for modulators of signal transduction of mammalian cells, we discovered two novel indolocarbazole antibiotics, indocarbazostatin and indocabazostatin B, from a culture broth of a Streptomyces sp. as inhibitors of NGF-induced neuronal differentiation in rat pheochromocytoma PC12 cells. Indocarbazostatin and indocarbazostatin B inhibited NGF-induced neurite outgrowth from PC12 cells at 6nM and 24nM, respectively, whereas K-252a inhibited at 200nM under our assay conditions.