Benastatin C is a polyketide synthase-derived benastatin that has been found inStreptomycesand has diverse biological activities.1,2It inhibits glutathione S-transferase (GST; IC50= 24 μg ml for the rat liver enzyme).2Benastatin C also inhibits the esterase activity of isolated porcine pancreatic lipase (IC50= 10 μg ml). It increases LPS- or concanavalin A-induced blastogenesis of isolated mouse spleen lymphocytes in a concentration-dependent manner. 1.Xu, Z., Schenk, A., and Hertweck, C.Molecular analysis of the benastatin biosynthetic pathway and genetic engineering of altered fatty acid-polyketide hybridsJ. Am. Chem. Soc.129(18)6022-6030(2007) 2.Aoyama, T., Kojima, F., Yamazaki, T., et al.Benastatins C and D, new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. Production, isolation, structure determination and biological activitiesJ. Antibiot. (Tokyo)46(5)712-718(1993)
Benastatin B is a polyketide synthase-derived benastatin that has been found in Streptomyces and has diverse biological activities. It inhibits glutathione S-transferase (GST; Ki = 3.7 µM for the rat liver enzyme).2 Benastatin B also inhibits the transglycosylase activity of A. baumannii, C. difficile, E. coli, and S. aureus recombinant penicillin-binding proteins (PBPs; IC50s = 16, 53.3, 30.7, and 31.6 µM, respectively).3 It is active against several bacteria, including methicillin-resistant S. aureus (MRSA; MIC = 3.12 µg ml).