Xanthine oxidase-catalysed oxidation of paracetamol.

Steps in the oxidation of xanthine to uric acid catalysed by milk xanthine oxidase.

A kinetic study of hypoxanthine oxidation by milk xanthine oxidase.

The course of the reaction sequence hypoxanthine----xanthine----uric acid catalysed by xanthine:oxygen oxidoreductase from milk was investigated on the basis of u.v. spectra taken during the course of hypoxanthine and xanthine oxidations. It was found that xanthine accumulated in the reaction mixture when hypoxanthine was used as a substrate. The time course of the concentrations of hypoxanthin...

In vitro study of 6-mercaptopurine oxidation catalysed by aldehyde oxidase and xanthine oxidase.

In spite of over 40 years of clinical use of 6-mercaptopurine, many aspects of complex pharmacology and metabolism of this drug remain unclear. It is thought that 6-mercaptopurine is oxidized to 6-thiouric acid through 6-thioxanthine or 8-oxo-6-mercaptopurine by one of two molybdenum hydroxylases, xanthine oxidase (XO), however, the role of other molybdenum hydroxylase, aldehyde oxidase (AO), i...

Oxidation of thiol compounds by catalase and peroxidase in the presence of manganese(II) and phenols [proceedings].

complex reacted rapidly with 02-. in a catalytic manner. The rate constant for O,-* dismutation was determined by competition of the iron porphyrin with Nitro Blue Tetrazolium in a xanthine/xanthine oxidase system at pH 10.1 ; a value of 3 x ~O'M-' .s-' at 20°C was obtained. The iron porphyrin had no effect on xanthine oxidase activity. Under our reaction conditions, at least 14 molecules of Oz...

Onion, a Potent Inhibitor of Xantine Oxidase

Onion (Allium Cepa) contains high levels of flavonoids. Although there are many studies indicating the inhibitory effects of flavonoids on xanthine oxidase, there is no report on the effect of onion on this enzyme. Therefore, in the present study, the inhibitory effects of onion on xanthine oxidase are investigated. Fresh filtered juice of onion was prepared and its inhibitory effect on guine...