title: Antioxidant activities of novel alpha-lipoic acid derivatives: N-(6, 8-dimercaptooctanoyl)-2-aminoethanesulfonate- and N-(6, 8-dimercaptooctanoyl)-L-aspartate-zinc complex.
abstract: Two new compounds, sodium N-(6, '8-dimercaptooctanoyl)-2-amino ethanesulfonate- and sodium N-(6, 8-dimercaptooctanoyl)-L-aspartate - zinc complex were synthesized from alpha-lipoyl-2-aminoethanesulfonate and alpha-lipoyl-L- aspartate by reduction of zinc/acetic acid respectively. These alpha-lipoyl-amino acids were obtained by a coupling of alpha-lipoic acid and 2-aminoethanesulfonate or L-aspartate, using a mixed anhydride method. Scavenging activities of these derivatives against hydroxyl radicals (*OH) was demonstrated directly using electron spin resonance (ESR) spectrometry with spin trapping. Otherwise an apparent superoxide anion radical (O2*-) scavenging effect of these derivatives may be due to the inhibition of 02*- generation system, i.e., xanthine oxidase. Scavenging activities of these compounds against nitric oxide radicals (NO*), and peroxynitrite (ONOO-) were estimated by the flow injection analysis using the Griess reagent and by a fluorescence spectrometry using dihydrorhodamine 123 respectively. Meanwhile, these derivatives showed protective effects against lipid peroxidation and protein carbonyl formation. Scavenging activities against NO* and ONOO-, and inhibitory effects on protein carbonyl formation of these derivatives were much stronger than these of alpha-lipoic acid itself.
authors.affiliation: Kochi University of Technology, Kochi, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Noda
authors.forename: Kazumi
authors.initials: K
authors.lastname: Ogata
authors.forename: Akitane
authors.initials: A
authors.lastname: Mori
mesh_terms: D000476:Alkanesulfonates / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D015227:Lipid Peroxidation / Q000187:drug effects*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000476:Alkanesulfonates; D000975:Antioxidants; C496913:N-(6, 8-dimercaptooctanoyl)-L-aspartate - zinc; C496912:N-(6,8-dimercaptooctanoyl)-2-aminoethanesulfonate; D009942:Organometallic Compounds; D001224:Aspartic Acid