title: Substituent effects upon the catalytic activity of aromatic cyclic seleninate esters and spirodioxyselenuranes that act as glutathione peroxidase mimetics.
abstract: Substituent effects were studied in a series of aromatic cyclic seleninate esters and spirodioxyselenuranes that function as mimetics of the antioxidant selenoenzyme glutathione peroxidase. The methoxy-substituted selenurane proved the most efficacious catalyst for the reduction of hydrogen peroxide with benzyl thiol, and the reaction rates were enhanced for both classes by electron-donating substituents. Hammett plots indicated rho = -0.45 and -3.1 for the seleninates and selenuranes, respectively, suggesting that oxidation at Se is the rate-determining step in their catalytic cycles.
authors.affiliation: Department of Chemistry, University of Calgary, Calgary, Alberta, Canada.
authors.forename: David J
authors.initials: DJ
authors.lastname: Press
authors.forename: Eric A
authors.initials: EA
authors.lastname: Mercier
authors.forename: Dusan
authors.initials: D
authors.lastname: Kuzma
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Back
mesh_terms: D002384:Catalysis; D003500:Cyclization; D004952:Esters; D005979:Glutathione Peroxidase / Q000737:chemistry*; D018716:Molecular Mimicry; D012643:Selenium / Q000737:chemistry*
chemical_list: D004952:Esters; D005979:Glutathione Peroxidase; D012643:Selenium