title: Reevaluation of superoxide scavenging activity of dihydrolipoic acid and its analogues by chemiluminescent method using 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo-[1,2-a]pyrazine-3-one (MCLA) as a superoxide probe.
abstract: The superoxide scavenging activity of dihydrolipoic acid and its analogues has been reevaluated by a chemiluminescence method using MCLA as a superoxide indicator. The results demonstrated that all the compounds having the thiol chromophore in the molecule showed scavenging activity toward superoxide. The short-chain analogue, tetranor-dihydrolipoic acid, showed almost the same scavenging activity as that of dihydrolipoic acid; however, bisnor-dihydrolipoic acid showed weaker scavenging activity than that of dihydrolipoic acid. The reaction rates of dihydrolipoic acid, bisnor-dihydrolipoic acid, and tetranor-dihydrolipoic acid were calculated from the competitive inhibition of MCLA-superoxide reaction. Thus, it was concluded that dihydrolipoic acid and the analogues are good scavengers of superoxide radical anion.
authors.affiliation: Department of Molecular and Cell Biology, University of California at Berkeley 94720-3200, USA.
authors.forename: S
authors.initials: S
authors.lastname: Matsugo
authors.forename: T
authors.initials: T
authors.lastname: Konishi
authors.forename: D
authors.initials: D
authors.lastname: Matsuo
authors.forename: H J
authors.initials: HJ
authors.lastname: Tritschler
authors.forename: L
authors.initials: L
authors.lastname: Packer
mesh_terms: D003545:Cysteine / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D008163:Luminescent Measurements; D015335:Molecular Probes; D011719:Pyrazines / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry*; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D016166:Free Radical Scavengers; D007093:Imidazoles; D015335:Molecular Probes; D011719:Pyrazines; D013481:Superoxides; C063412:2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo(1,2-alpha)pyrazin-3-one; D008063:Thioctic Acid; C015144:dihydrolipoic acid; D003545:Cysteine