caa a22 4500 477082580 CHVBK 20180405111454.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF01938881 doi (NATIONALLICENCE)springer-10.1007/BF01938881 (−)-Epigallocatechin gallate, a polyphenolic tea antioxidant, inhibits peroxynitritemediated formation of 8-oxodeoxyguanosine and 3-nitrotyrosine [Elektronische Daten] [E. Fiala, R. Sodum, M. Bhattacharya, H. Li] Reaction with peroxynitrite at pH 7.4 and 37°C was found to increase the 8-oxodeoxyguanosine levels in calf thymus DNA 35-38-fold. This oxidation of deoxyguanosine, as well as the peroxynitrite-mediated nitration of tyrosine to 3-nitrotyrosine, was significantly inhibited by ascorbic acid, glutathione and (−)-epigallocatechin gallate, a polyphenolic antioxidant present in tea. For 50% inhibition of the oxidation of deoxyguanosine to 8-oxodeoxyguanosine, 1.1, 7.6 of 0.25 mM ascorbate, glutathione or (−)-epigallocatechin gallate, respectively, was required. For 50% inhibition of tyrosine nitration, the respective concentrations were 1.4, 4.6 or 0.11 mM. Thus, (−)-epigallocatechin gallate is a significantly better inhibitor of both reactions than either ascorbate or glutathione. Reaction of (−)-epigallocatechin gallate with peroxynitrite alone resulted in the formation of a number of products. Ultraviolet spectra of two of these suggest that the tea polyphenol and/or its oxidation products are nitrated by peroxynitrite. Birkhäuser Verlag, 1996 Antioxidant nationallicence epigallocatechin gallate nationallicence tea polyphenols nationallicence 3-nitrotyrosine nationallicence 8-oxodeoxyguanosine nationallicence Fiala E. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut Sodum R. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut Bhattacharya M. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut Li H. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut Experientia Birkhäuser-Verlag 52/9(1996-09-01), 922-926 0014-4754 52:9<922 1996 52 18 https://doi.org/10.1007/BF01938881 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01938881 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fiala E. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut NATIONALLICENCE 700 1- Sodum R. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut NATIONALLICENCE 700 1- Bhattacharya M. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut NATIONALLICENCE 700 1- Li H. American Health Foundation, 1 Dana Road, 10595, Valhalla, New York, New York, USA aut NATIONALLICENCE 773 0- Experientia Birkhäuser-Verlag 52/9(1996-09-01), 922-926 0014-4754 52:9<922 1996 52 18 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer