Ubiquinol oxidase has been reconstituted from ubiquinol-cytochrome c reductase (Complex III), cytochrome c and cytochrome c oxidase (Complex IV). The steady-state level of reduction of cytochrome c by ubiquinol-2 varies with the molar ratios of the complexes and with the presence of antimycin in a way that can be quantitatively accounted for by a model in which cytochrome c acts as a freely dif...

Ubiquinol-6 (reduced coenzyme Q6) was more effective than ubiquinone-6 and almost as effective as a-tocopherol in reducing the stable free radical diphenyl-p-picrylhydrazyl. The antioxidant activity of ubiquinol-6 was measured at low oxygen concentrations with an oxygen electrode. Ubiquinol-6 was found to be as e5cient as a-tocopherol as an inhibitor of the heme-catalyzed peroxidation of arachi...

The AOX (alternative oxidase) is a non-protonmotive ubiquinol-oxygen oxidoreductase that couples the oxidation of ubiquinol with the complete reduction of water. Although it has long been recognized that it is ubiquitous among the plant kingdom, it has only recently become apparent that it is also widely found in other organisms including some human parasites. In this paper, we review experimen...

The solvation properties of ubiquinone-10 and ubiquinol-10 in a wide variety of solvents of polarity varying from alkanes to water are reported. Greatest solubility is observed in solvents of intermediate polarity and particularly where low polarity is combined with a pronounced tendency to interact with the benzoquinone substituent of the ubiquinone molecule. This includes solvents like chloro...

BACKGROUND Considering all the couples willing and trying to get pregnant, the incidence of infertility is 15% of which approximately half of the cases are due to the male factors. OBJECTIVES The aim of this study was the investigation of the effects of ubiquinol, reduced form of coenzyme Q10 (Co-Q10), an empiric treatment modality, on sperm parameters in idiopathic subfertility. PATIENTS A...

Ubiquinol-6 (reduced coenzyme Q6) was more effective than ubiquinone-6 and almost as effective as a-tocopherol in reducing the stable free radical diphenyl-p-picrylhydrazyl. The antioxidant activity of ubiquinol-6 was measured at low oxygen concentrations with an oxygen electrode. Ubiquinol-6 was found to be as e5cient as a-tocopherol as an inhibitor of the heme-catalyzed peroxidation of arachi...

Supplementation with antioxidants and its benefit-risk relationship have been largely discussed in the elderly population. We evaluated whether antioxidants supplementation improved the biochemical profile associated with oxidative metabolism in elderly cardiovascular patients. Patients (n = 112) received daily supplementation with α-TP 400 mg, beta-carotene 40 mg, and vitamin C 1000 mg for 2 m...

Molecules of mitochondrial cardiolipin (CL) get selectively oxidized upon oxidative stress, which triggers the intrinsic apoptotic pathway. In a chemical model most closely resembling the mitochondrial membrane-liposomes of pure bovine heart CL-we compared ubiquinol-10, ubiquinol-6, and alpha-tocopherol, the most widespread naturally occurring antioxidants, with man-made, quinol-based amphiphil...

To investigate the protein-ubiquinone interaction in the bovine heart mitochondrial succinate-cytochrome c reductase region of the respiratory chain, three fluorine substituted ubiquinone derivatives, 2,3-dimethoxy-6-(9'-fluorodecyl)-1,4-benzoquinone (9FQ), 2-methoxy-5-trifluoromethyl-6-decyl-1,4-benzoquinone (TFQ), and 2-methoxy-5-trifluoromethyl-6-(9'-fluorodecyl)-1,4-benzoquinone (9FTFQ), we...