title: Inhibition of peroxynitrite- and peroxidase-mediated protein tyrosine nitration by imidazole-based thiourea and selenourea derivatives.
abstract: In the present study, the synthesis and characterization of a series of N-methylimidazole-based thiourea and selenourea derivatives are described. The new compounds were also studied for their ability to inhibit peroxynitrite (PN)- and peroxidase-mediated nitration of protein tyrosine residues. It has been observed that the selenourea derivatives are more efficient than the thiourea-based compounds in the inhibition of protein nitration. The higher activity of selenoureas as compared to that of the corresponding thioureas can be ascribed to the zwitterionic nature of the selenourea moiety. Single crystal X-ray diffraction studies on some of the thiourea and selenourea derivatives reveal that the C=S bonds in thioureas possess more of double bond character than the C=Se bonds in the corresponding selenoureas. Therefore, the selenium compounds can react with PN or hydrogen peroxide much faster than their sulfur analogues. The reactions of thiourea and selenourea derivatives with PN or hydrogen peroxide produce the corresponding sulfinic or seleninic acid derivatives, which upon elimination of sulfurous/selenous acids produce the corresponding N-methylimdazole derivatives.
authors: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560 012, India.
authors: Krishna P
authors: KP
authors: Bhabak
authors: Kandhan
authors: K
authors: Satheeshkumar
authors: Subramaniam
authors: S
authors: Jayavelu
authors: Govindasamy
authors: G
authors: Mugesh
mesh_terms: D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D007093:Imidazoles / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009566:Nitrates / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D016566:Organoselenium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D009195:Peroxidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013237:Stereoisomerism; D013890:Thiourea / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D014443:Tyrosine / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D007093:Imidazoles; D009566:Nitrates; D016566:Organoselenium Compounds; C081959:selenourea; D030421:Peroxynitrous Acid; D012710:Serum Albumin, Bovine; D014443:Tyrosine; D014508:Urea; D009195:Peroxidase; D013890:Thiourea; C018100:1-methylimidazole