Identification of a new flavanol glucoside from barley (Hordeum vulgare L.) and malt

Abstract.

(2R,3S)-Catechin-7-O-β-D-glucopyranoside is isolated from barley (Hordeum vulgare L.) and malt for the first time. For identification, the glucoside was isolated from acetone-water extracts of malt by polyamide clean-up and semi-preparative HPLC. The structure was elucidated by various NMR techniques, fast atom bombardment mass spectrometry and UV and circular dichroism spectroscopy. The investigation of 20 different barley varieties and the corresponding malts by HPLC with UV and coulometric electrode array detection revealed that the amount of the glucoside increases during malting. In contrast, the content of the monomeric (+)-catechin decreases and (–)-epicatechin was not detected.