complex ii

Atpenin A5 is a potent and highly specific complex II inhibitor (IC50 ~10 nM), as well as an effective mKATP channel agonist and cardioprotective agent [1].

Etoposide (VP-16-213) is a topoisomerase II inhibitor that inhibits DNA synthesis by forming a complex with topoisomerase II and DNA (IC50=60.3 μM). Etoposide has antitumor activity and induces apoptosis and autophagy.

D-Glucaric acid potassium (D-Saccharic acid potassium salt) is a compound formed from oxidizing sugars, which can be used to test for the presence of hepatic enzyme induction. Studies indicate that D-glucuronolactone dehydrogenase oxidizes D-Saccharic acid potassium salt into D-glucaro-l,4;6,3-dilactone. Alternate studies suggest that D-Saccharic acid potassium salt forms a complex with Cu(II) and H2O2to decolorize azo, acridine, triphenyl methane, anthraquinone and thiazine-based dyes.

Malonic acid (propanedioic acid) is the archetypal example of a competitive inhibitor: it acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain. Malonic acid is found to be associated with malonyl-CoA decarboxylase deficiency, which is an inborn error of metabolism.

Napyradiomycin A1is a fungal metabolite originally isolated fromC. rubraand has diverse biological activities.1,2It is active againstS. aureus,M. luteus,B. anthracis,C. bovis, andM. smegmatis(MICs = 1.56-12.5 μg/ml).1Napyradiomycin A1is an estrogen receptor antagonist (IC50= 4.2 μM in rat uterine homogenates).2It also inhibits mitochondrial NADH:ubiquinone oxidoreductase (complex I) and succinate:ubiquinone oxidoreductase (complex II) activities in bovine heart homogenates (IC50s = 20 and 9.7 μM, respectively).3 1.Shiomi, K., Iinuma, H., Hamada, M., et al.Novel antibiotics napyradiomycins. Production, isolation, physico-chemical properties and biological activityJ. Antibiot. (Tokyo)39(4)487-493(1986) 2.Hori, Y., Abe, Y., Shigematsu, N., et al.Napyradiomycins A and B1: Non-steroidal estrogen-receptor antagonists produced by a StreptomycesJ. Antibiot. (Tokyo)46(12)1890-1893(1993) 3.Yamamoto, K., Tashiro, E., Motohashi, K., et al.Napyradiomycin A1, an inhibitor of mitochondrial complexes I and IIJ. Antibiot. (Tokyo)65(4)211-214(2012)

Lacto-N-triose II, a core structural unit of human milk oligosaccharides (HMOs), possesses nutraceutical potentials and is utilized in the synthesis of complex HMOs [1].

Harzianopyridone is an atpenin-like compound that functions as an inhibitor of mammalian and nematode mitochondrial complex II, also known as succinate:ubiquinone oxidoreductase (SQR), demonstrating IC50 values of 0.017, 0.2, and 2 μM against bovine, rat, and nematode complex II, respectively. Additionally, it inhibits nematode quinol-fumarate reductase (QFR) with an IC50 value of 0.36 μM. Significantly selective for complex II over complexes I and III in rats and cattle, as well as complex I in nematodes, with IC50 values exceeding 100 μM, it exhibits notable antibacterial and antifungal properties, with EC50 values of 35.9, 42.2, 60.4, and 50.2 μg ml against R. solani, S. rolfsii, M. phaseolina, and F. oxysporum, respectively.

Aquacobalamin, one of the primary forms of Vitamin B12 isolated from mammalian cells, accelerates the oxidation of the diazo dye Orange II in aqueous solutions containing HSO5-. Additionally, Aquacobalamin can reversibly bind with hydrogen peroxide to form a cobalt (III) hydroperoxide complex, with a dissociation constant of 0.25 mM.

Stigmatellin is an antibiotic derived from the cell mass of the myxobacterium, effective against yeasts (yeasts), filamentous fungi (filamentous fungi), and several Gram-positive bacteria (Gram-positive bacteria). Additionally, it serves as a potent inhibitor of photosynthetic electron (photosynthetic electron) transfer. Stigmatellin utilizes various sugars, polysaccharides, and acids from the citric acid cycle as substrates, inhibiting RNA and protein synthesis. It has two different inhibitory sites: one located on the reducing side of photosystem II and the other at the cytochrome b6 f complex. Stigmatellin holds potential for use in antimicrobial and photosynthesis research.