title: Protection by organotellurium compounds against peroxynitrite-mediated oxidation and nitration reactions.
abstract: Diaryl tellurides effectively protect against peroxynitrite-mediated oxidation of dihydrorhodamine 123 (DHR), hydroxylation of benzoate, and nitration of 4-hydroxyphenylacetate (HPA). Bis(4-aminophenyl) telluride offered the most efficient protection against oxidation of DHR induced by peroxynitrite. Protection by this compound was approximately 3 times more effective than that afforded by its selenium analog, bis(4-aminophenyl) selenide, and 11 times more effective than selenomethionine. When peroxynitrite was infused to maintain a steady-state concentration, bis(4-aminophenyl) telluride in the presence of GSH, but neither bis(4-aminophenyl) telluride nor GSH alone, effectively inhibited the peroxynitrite-mediated hydroxylation of benzoate. The inhibition of nitration was most pronounced using bis(4-hydroxyphenyl) telluride, and this compound was ca. 3 times more effective than selenomethionine. Bis(4-aminophenyl) telluride also protected proteins in lysates from human skin fibroblasts from peroxynitrite-mediated nitration of tyrosine residues more effectively than selenomethionine. These data establish a potential biological or pharmacological role of organotellurium compounds in the defense against peroxynitrite.
authors.affiliation: Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Briviba
authors.forename: R
authors.initials: R
authors.lastname: Tamler
authors.forename: L O
authors.initials: LO
authors.lastname: Klotz
authors.forename: L
authors.initials: L
authors.lastname: Engman
authors.forename: I A
authors.initials: IA
authors.lastname: Cotgreave
authors.forename: H
authors.initials: H
authors.lastname: Sies
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001565:Benzoates / Q000378:metabolism; D019817:Benzoic Acid; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D009566:Nitrates / Q000037:antagonists & inhibitors*; D009942:Organometallic Compounds / Q000494:pharmacology*; D016877:Oxidants / Q000037:antagonists & inhibitors*; D010084:Oxidation-Reduction; D010648:Phenylacetates / Q000494:pharmacology; D012235:Rhodamines / Q000378:metabolism; D013691:Tellurium / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001565:Benzoates; D009566:Nitrates; D009942:Organometallic Compounds; D016877:Oxidants; D010648:Phenylacetates; D012235:Rhodamines; C058319:dihydrorhodamine 123; C039642:peroxynitric acid; C026246:4-hydroxyphenylacetate; D019817:Benzoic Acid; D005979:Glutathione Peroxidase; D013691:Tellurium