An antibiotic Isolated from Streptomyces parvulus. A Potent, selective and competitive cell permeable rasfarnesyltransferase (FTase) inhibitor (IC50 = 30 nM). Does not affect geranylgeranyltransferase (GGTase) (IC50 = 180 μM). Blocks insulin-induced MAP kinase activation in rat cardiac myocytes (19 μM).μM). Inhibition is competitive with respect to farnesyl pyrophosphate and non-competitive with respect to Ras. MW: 550.64. Purity ≥96% by HPLC