Chemical and enzymatic oxidation of 2-aryl-1,3-oxathiolanes: mechanism of the hepatic flavin-containing monooxygenase
The reaction of NaIO sub(4), H sub(2)O sub(2), and highly purified and microsomal hog and rat liver flavin-containing monooxygenase with 2-aryl-1,3-oxathiolanes was investigated. The rho values determined from Hammett plots for the rate of S-oxygenation are consistent with substantial nucleophilic c...
Saved in:
Published in | Journal of the American Chemical Society Vol. 111; no. 13; pp. 4844 - 4852 |
---|---|
Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
1989
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The reaction of NaIO sub(4), H sub(2)O sub(2), and highly purified and microsomal hog and rat liver flavin-containing monooxygenase with 2-aryl-1,3-oxathiolanes was investigated. The rho values determined from Hammett plots for the rate of S-oxygenation are consistent with substantial nucleophilic character for the chemical reaction but this does not preclude radical character in the reaction. For the biotransformation reactions, the data provide evidence for a minor role of cytochrome P-450 in the S-oxygenation of 2-aryl-1,3-oxathiolanes, but the flavin-containing monooxygenase represents by far the major pathway for S-oxide formation. The diastereochemical outcome of the S-oxygenation of 2-aryl-1,3-oxathiolanes was determined and, in general, hog liver flavin-containing monooxygenase demonstrated considerable S-oxygenation stereoselectivity while rat liver flavin-containing monooxygenase (FMO) was markedly less stereoselective. The reactions of 2-aryl-1,3-oxathiolanes with H sub(2)O sub(2) and FMO serve to demonstrate the electronic and stereochemical requirements for S-oxygenation of dialkyl sulfides and provide evidence that rat and hog liver FMO are two different forms of the same enzyme. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/ja00195a041 |