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(-)-Epicatechin inhibits nitration and dimerization of tyrosine in hydrophilic as well as hydrophobic environments. Biochem Biophys Res Commun 2001 Dec 21;289(5):1334-8

Date

12/14/2001

Pubmed ID

11741342

DOI

10.1006/bbrc.2001.6134

Scopus ID

2-s2.0-0035930940 (requires institutional sign-in at Scopus site)   32 Citations

Abstract

The flavanol (-)-epicatechin is known to protect against peroxynitrite-induced nitration and oxidation reactions. This study investigated the protection afforded by (-)-epicatechin against both these reaction types on one target molecule, the aminoacid tyrosine, in a hydrophilic milieu as well as with a lipophilic tyrosine derivative, N-t-BOC l-tyrosine tert-butyl ester (BTBE), bound to liposomes. The flavanol efficiently attenuated both tyrosine nitration and tyrosine dimerization (which is based on an initial oxidation reaction) and was active in the hydrophilic and hydrophobic systems at similar IC(50) values, approximately 0.02-0.05 mol (-)-epicatechin/mol peroxynitrite. Related procyanidin oligomers of different chain-length (dimer to octamer) were also tested for their protective properties, and exhibited protection that, on a monomer basis, was in the same order of magnitude as those for (-)-epicatechin.

Author List

Schroeder P, Zhang H, Klotz LO, Kalyanaraman B, Sies H

Author

Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Antioxidants
Catechin
Dimerization
In Vitro Techniques
Liposomes
Nitrates
Peroxynitrous Acid
Reactive Oxygen Species
Tyrosine