title: Sulfur-containing compounds quench 3,7-dihydro-2-methyl-6-(4-methoxyphenyl)imidazol[1,2-a]pyrazine-3-one chemiluminescence: Discrimination between true antioxidants and quenchers using xanthine oxidase.
abstract: The probe 3,7-dihydro-2-methyl-6-(4-methoxyphenyl)imidazol[1,2-a]pyrazine-3-one (MCLA) is widely used for studying the superoxide anion production and the efficiency of antioxidants in biological systems. Here we report that a number of sulfur-containing compounds applied in biochemical and cytological studies are able to suppress MCLA-derived chemiluminescence (MDCL) independent of their capability to scavenge superoxide anion. The most effective MDCL quenchers appeared to be the substances with thiocarbamoyl and thiocarbonyl groups coupled to cyclic molecules and several thiol- and disulfide-containing compounds. The analysis of MDCL kinetics in a xanthine oxidase system allows one to rapidly discriminate between true antioxidants and the quenchers of chemiluminescence.
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142290 Moscow Region, Russia. krugalex@rambler.ru
authors.forename: Alexey G
authors.initials: AG
authors.lastname: Kruglov
authors.forename: Anna B
authors.initials: AB
authors.lastname: Nikiforova
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Shatalin
authors.forename: Viktoria V
authors.initials: VV
authors.lastname: Shubina
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Fisyuk
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Akatov
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism*; D008163:Luminescent Measurements / Q000379:methods*; D011719:Pyrazines / Q000737:chemistry / Q000378:metabolism*; D013457:Sulfur Compounds / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D007093:Imidazoles; D011719:Pyrazines; D013457:Sulfur Compounds; C063412:2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo(1,2-alpha)pyrazin-3-one; D014969:Xanthine Oxidase