Inhibitory mechanism of sinapinic acid against peroxynitrite-mediated tyrosine nitration of protein in vitro.
The peroxynitrite-scavenging ability of some phenolic antioxidants, p-coumaric acid, caffeic acid and sinapinic acid, was examined and compared with ascorbic acid and tocopherol using 3-nitrotyrosine formation as a marker. Among these, caffeic acid and sinapinic acid strongly inhibited the formation of 3-nitrotyrosine in protein. The treatment of protein with peroxynitrite in the presence of sinapinic acid, but not caffeic acid, produced a novel product determined by reversed-phase high performance liquid chromatography (HPLC). The product formed was purified and then identified as a mono-lactone type dimer (ML) of sinapinic acid by nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS). This ML was converted from a di-lactone type dimer, obtained from sinapinic acid with peroxidase/hydrogen peroxide, in neutral buffer. In this report, we have proposed that the ML of sinapinic acid is generated via one-electron oxidation by peroxynitrite treatment.
Niwa
T
T
Department of Research and Development, San-ei Sucrochemical Co., Ltd., Chita, Japan.
Doi
U
U
Kato
Y
Y
Osawa
T
T
D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism*; D019281:Dimerization; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009566:Nitrates / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D011506:Proteins / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism
D003373:Coumaric Acids; D009566:Nitrates; D011506:Proteins; C039642:peroxynitric acid; C002744:3-nitrotyrosine; D014443:Tyrosine; C073734:sinapinic acid