title: Evaluation of scavenging rate constants of DOPA and tyrosine enantiomers against multiple reactive oxygen species and methyl radical as measured with ESR trapping method.
abstract: The scavenging rates of DOPA (dl- and l-3-(3,4-dihydroxyphenyl)alanine) and Tyr (tyrosine (dl- and l-3-(4-hydroxyphenyl)alanine)) against five reactive oxygen species (ROS) and methyl radical were measured with the use of electron spin resonance (ESR) spin-trapping method and the scavenging rate constants of DOPA and Tyr were determined. The scavenging rate constants for multiple active species increased in the order of O2(-)<RO<(1)O2<H3C<HO for Tyr and RO≈O2(-)<(1)O2≈H3C<HO for DOPA, and the differences in the radical scavenging abilities for l-enantiomers and dl-mixtures of DOPA and Tyr were shown. Further, based on the redox potentials, we have suggested that the primary chemical process of antioxidant reactions with O2(-) and (1)O2 can be characterized with the electron transfer of antioxidants (DOPA and Tyr).
authors: Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. Electronic address: ysueishi@okayama-u.ac.jp.
authors: Yoshimi
authors: Y
authors: Sueishi
authors: Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
authors: Tsubasa
authors: T
authors: Takemoto
mesh_terms: D004295:Dihydroxyphenylalanine / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry*; D007700:Kinetics; D007980:Levodopa / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry*; D019097:Spin Trapping; D013237:Stereoisomerism; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; C051224:methyl radical; D014443:Tyrosine; D007980:Levodopa; D004295:Dihydroxyphenylalanine; D008697:Methane
keywords: DOPA; ESR spin trapping; Radical scavenging rate constant; Tyrosine