Flavan-3-ols having a γ-lactam from the roots of actinidia arguta inhibit the formation of advanced glycation end products in vitro

Abstract

Two new flavan-3-ols, 6-(2-pyrrolidinone-5-yl)-(-)-epicatechin (1) and 8-(2-pyrrolidinone-5-yl)-(-)-epicatechin (2), as well as five known compounds, (-)-epicatechin (3), (+)-catechin (4), proanthocyanidin B-4 (5), (+)- pinoresinol, and p-hydroxybenzoic acid, were isolated from an EtOAc-soluble extract of the roots of Actinidia arguta. The structures of compounds 1 and 2 were elucidated by spectroscopic data interpretation, particularly by extensive 1D- and 2D-NMR studies. All the isolates were evaluated in vitro for inhibitory activity on the formation of advanced glycation end products (AGEs). Of these, compounds 1-5 exhibited significant inhibitory activity against AGEs formation with IC50 values ranging from 10.1 to 125.2 μm. © 2009 Pharmaceutical Society of Japan.