Studies on Adrenal Steroid Hydroxylases

Chemistry of superoxide ion. I. Oxidation of 3,5-di-tert-butylcatechol with potassium superoxide

“…Several steps undoubtedly involve not only superoxide ion but also molecular oxygen, because a considerable amount of gaseous oxygen was absorbed during the reaction under oxygen pressure. Some radical intermediates in Scheme I would react Journal of the American Chemical Society j 98:6 / March (15) in the base catalyzed oxy-OH peroxy radical or ion, both of which can easily be converted to hydrogen peroxide. The reaction of 3,5-di-ze/'Z-butyl-oquinone 5 with hydrogen peroxide in alkaline aqueous methanol has been reported to give oxidative cleavage exclusively at the 1,6-position.29 While the product distribution obtained in the present investigation seems to be somewhat different from that reported for the hydrogen peroxide oxidation of 5, there is no doubt that the oxidation by superoxide ion cannot be free from the effects of the hydrogen peroxide formed during the reaction.…”

Properties of crystalline reduced nicotinamide adenine dinucleotide phosphate-adrenodoxin reductase from bovine adrenocortical mitochondria. I. Physicochemical properties of holo- and apo-NADPH-adrenodoxin reductase and interaction between non-heme iron proteins and the reductase

“…Formation of a complex of bovine NADPH-adrenodoxin reductase with adrenodoxin, its apoadrenodoxin, or other non-heme iron proteins caused quenching of fluorescence of the tryptophanyl residue and bound FAD ^^JaDPH1 -adrenodoxin reductase is a component of the NADPH-cytochrome P-450 linked monooxygenase system in adrenocortical mitochondria (Nakamura et al, 1966;Omura et al, 1966). The formation of a complex between NADPH-adrenodoxin reductase and adrenodoxin has been demonstrated spectrophotometrically and the effects of ionic strength and heat stability on formation of this complex have been reported (Chu and Kimura. 1973a).…”

The reaction of catechol and derivatives with potassium superoxide

“…The intervention of the superoxide anion radical in enzyme oxidation systems has recently been the subject of a number of investigations (1,2). Its formation is the result of a one electron reduction of molecular oxygen and its presence can be tested by the use of superoxide dismutase, an enzyme which inhibits t h e oxidations by destruction of superoxide in these systems.…”