ИСТИНА

Ortho-carborane (1,2-C2B10H12, a cluster composed of boron, carbon and hydrogen atoms) was found to be a carrier of protons in lipid membranes and membranes of mitochondria suggesting that it can reversibly release hydrogen ions and diffuse through the membrane in neutral and anionic forms. Similar to classical uncouplers, it stimulated mitochondrial respiration and decreased the membrane potential at concentrations of tenths of micromoles. Pyranine-loaded liposomes and planar lipid bilayers (BLM) were used as a proton transport assay. Meta-isomer, 1,7-C2B10H12, having two carbons separated in cluster by boron atom lacked protonophoric activity. The activities of 1-methyl-o-carborane and especially 1-benzyl-o-carborane on bilayer lipid membrane and pyranine-loaded liposomes were found to be more pronounced compared to the pristine molecule. However, 1-benzyl-o-carborane exhibited both protonophoric activity and inhibition of succinate-dehydrogenase on mitochondria and hardly can be regarded as effective uncoupler. The finding of new class of uncoupling compounds is of substantial interest owing to anti-obesity and anti-diabetic properties of uncouplers.