Manumycin A

Antibiotic, Potent, selective and competitive cell-permeable rasfarnesyltransferase inhibitor (IC50 = 30 nM), Does not affect geranylgeranyltransferase (IC50 = 180 µM), Inhibition is competitive with respect to farnesyl pyrophosphate and non-competitive with respect to Ras, Neutral sphingomyelinase inhibitor, Blocks insulin-induced MAP kinase activation in rat cardiac myocytes (19 µM). Isolated from Streptomyces parvulus.