Vatiquinone, also known as EPI 743, is an orally bioavailable para-benzoquinone being developed for inherited mitochondrial diseases. The mechanism of action of EPI-743 involves augmenting the synthesis of glutathione, optimizing metabolic control, enhanc
Antimycin A4 is an active component of the antimycin A antibiotic complex that is more polar than antimycin A1 , antimycin A2 , and antimycin A3 . Antimycin A4 inhibits ATP-citrate lyase with a Ki value of 64.8 μM. The antimycin A complex is a mixture of antimycins A1, A2, A3, and A4 that demonstrates antifungal, insecticidal, nematocidal, and piscicidal properties. It blocks mitochondrial respiration and can deplete cellular levels of ATP via inhibition of complex III of the mitochondrialelectrontransport chain (ETC). Antimycin A prevents the transfer of electrons between the b-cytochromes and ubiquinone at the Q(inner) site of complex III. This results in the stabilization of the ubisemiquinone radical at the Q(outer) site of complex III, leading to increased production of superoxide. Antimycin A is widely used in research to shunt electron flow through the ETC to study the chemical details of oxygen respiration. Additionally, antimycin A has been shown to inhibit Bcl-2 and Bcl-xL proteins, inducing apoptosis.
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 mitochondrialelectrontransport 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 mitochondrialelectrontransport in insect muscle comparing with rotenoneSci. Insect Control34(3)126-134(1969)