Dimerumic acid as an antioxidant from the mold, Monascus anka: the inhibition mechanisms against lipid peroxidation and hemeprotein-mediated oxidation

• Published in: Biochemical pharmacology 2002-03, Vol.63 (5), p.1019-1026
• Main Authors: Taira, Junsei, Miyagi, Chika, Aniya, Yoko
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - pharmacology; Ascomycota - chemistry; Biological and medical sciences; Dimerumic acid; Electron spin resonance (ESR); Ferrylmyoglobin; Free Radical Scavengers - pharmacology; General and cellular metabolism. Vitamins; Hemeproteins - metabolism; Lipid peroxidation; Lipid Peroxidation - drug effects; Male; Medical sciences; Metmyoglobin - metabolism; Microsomes, Liver - drug effects; Microsomes, Liver - metabolism; Monascus anka; Nitroxide radical; Oxidation-Reduction - drug effects; Peroxides - metabolism; Pharmacology. Drug treatments; Piperazines - pharmacology; Rats; Rats, Sprague-Dawley
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/S0006-2952(01)00923-6

This study aimed to investigate the antioxidant mechanism of dimerumic acid isolated as the active component with a radical scavenging action from the mold Monascus anka, traditionally used for the fermentation of foods. Dimerumic acid inhibited NADPH- and iron(II)-dependent lipid peroxidation (LPO) of rat liver microsomes at 20 and 200 μM, respectively. When ferrylmyoglobin was incubated with dimerumic acid, the myoglobin was scavenged and an electron spin resonance (ESR) signal with nine peaks was observed. The spin adduct was identified as a nitroxide radical by analysis of hyperfine structure. Similar ESR signal was also detected by incubation of dimerumic acid with peroxyl radicals. Thus, it was clarified that the antioxidant action of dimerumic acid is due to one electron donation of the hydroxamic acid group in the dimerumic acid molecule toward oxidants resulting in formation of nitroxide radical.