Purity 98%. Isozyme-selective inhibitor of protein kinase C (PKC); competitively and reversibly inhibits PKCbetaI and PKCbetaII (IC50 values are 4.7 and 5.9 nM respectively). Selective for PKCbeta over other PKC isozymes (IC50values are 0.052, 0.25, 0.30, 0.36, 0.60 and >100 muM for PKCeta, -delta, -gamma, -alpha, -epsilon and -zeta respectively). Exhibits selectivity for PKC over other ATP-dependent kinases, including protein kinase A, casein kinase and src).