Protein kinase C inhibitor; alkaloid isolated from Streptomyces staurosporeus. Isoln: S. Omura et al., J. Antibiot. 30, 275 (1977). Crystal and molecular structure: A. Furusaki et al., J. Chem. Soc. Chem. Commun. 1978, 800; eidem, Bull. Chem. Soc. Jpn. 55, 3681 (1982). Corrected stereochemistry: N. Funato et al., Tetrahedron Lett. 35, 1251 (1994). Total synthesis: J. T. Link et al., J. Am. Chem. Soc. 117, 552 (1995); idem et al., ibid. 118, 2825 (1996). Biosynthetic studies: D. Meksuriyen, G. A. Cordell, J. Nat. Prod. 51, 884, 893 (1988); S.-W. Yang et al., ibid. 62 1551 (1999). HPLC determn in blood and pharmacokinetics in rats: L. R. Gurley et al., J. Chromatogr. B 712, 211 (1998). Inhibition of protein kinase C: T. Tamaoki et al., Biochem. Biophys. Res. Commun. 135, 397 (1986); of other protein kinases: U. T. Rüegg, G. M. Burgess, Trends Pharmacol. Sci. 10, 218 (1989). Induction of apoptosis: E. Falcieri et al., Biochem. Biophys. Res. Commun. 193, 19 (1993); R. Bertrand et al., Exp. Cell Res. 211, 314 (1994); of tyrosine phosphorylation: D. Rasouly, P. Lazarovici, Eur. J. Pharmacol. 269, 255 (1994).