Novel, very potent PKC inhibitor with high selectivity for the A-group of PKC isotypes (alpha, beta, and gamma), with IC50 values in the 2-10 nM range. Little or no inhibition of the B- and C-groups of PKC isotypes, even at much higher concentrations. Bioorg. Med. Chem. Lett. 3: 1959-1964 (1993).