Piericidin B is a bacterial metabolite that has been found inS. mobaraensisand has insecticidal and antimicrobial activities.^1,2,3It inhibits NADH oxidase activity in isolated bovine heart mitochondria and inhibits respiration in isolated rat liver mitochondria and isolated cockroach (P. americana) muscle mitochondria.^2,3Topical application of piericidin B (4 µg/insect) induces mortality in 87.5% of houseflies (M. domestica).¹It induces 93.3, 100, and 100% mortality in rice stem borer (C. simples), silkworm (B. mori), and green caterpillar (P. rapae) larvae, respectively, when applied at respective concentrations of 60, 4.8, and 96 µg/larva. Piericidin B is active against the fungiT. asteroides,T. rubrum,M. gypseum, andC. neoforms(MICs = 20, 10, 20, and 2 µg/ml, respectively), as well as the bacteriaM. luteusandP. vulgaris(MICs = 50 and 100 µg/ml, respectively).

1.Takahashi, N., Suzuki, A., Kimura, Y., et al.Isolation, structure and physiological activities of piericidin B, natural Insecticide produced by a StreptomycesAgr. Biol. Chem.32(9)1115-1122(1968) 2.Jeng, M., Hall, C., Crane, F.L., et al.Inhibition of mitochondrial electron transport by piericidin A and related compoundsBiochemistry7(4)1311-1322(1968) 3.Mitsui, T., Fukami, J.-I., Fukunaga, K., et al.Studies on piericidin. I. : Effects of piericidin A and B on mitochondrial electron transport in insect muscle comparing with rotenoneSci. Insect Control34(3)126-134(1969)