Potent protein kinase C (PKC) inhibitor (IC50 = 7.9 nM). Discriminates between Ca2+-dependent and -independent isoforms of PKC in vitro; selectively inhibits PKCα and PKCβ1 (IC50 values are 2.3 and 6.2 nM respectively). Does not inhibit the activity of PKCδ, -ε, or -ζ (IC50 > 3μM). Also inhibits TrkA, TrkB, JAK2 and JAK3 tyrosine kinases (IC50 values are 5, 30, 130 and 370 nM respectively), PKCμ (PKD1) and the mitotic spindle checkpoint.