OXISURAN REDUCTION BY RABBIT TISSUE PREPARATIONS

Oxisuran, 2-[(methylsulfinyl)acetyl]pyridine is reduced to .alpha.-[(methylsulfinyl)methyl]-2-pyridenimethanol, oxisuranol, by cytoplasmic enzymes from rabbit liver, kidney, brain, intestine and lung. The cytoplasmic enzyme from liver is dependent on NADPH as cofactor and has an optimal pH of 6.0. Enzymatic activity is also present in liver mitochondria but at a lower specific activity. The cytoplasmic extracts catalyze the formation of 2 oxisuranol products, presumably the diastereoisomers described by Di Carlo and associates from in vivo studies. Verification of the product as oxisuranol was accomplished by TLC and mass spectrometry.