The polyphenol constituents of grape pomace

Chemical investigation of Chardonnay grape pomace has resulted in the isola tion of 17 polyphenols which were identified by NMR spectroscopy as gallic acid, its 3- and 4-beta-glucopyranosides, trans-caftaric acid, cis- and tra ns-coutaric acid, 2-hydroxy-5-(2-hydroxyethyl)phenyl-beta-glucopyranoside, catechin, epicatechin, procyanidin B1, quercetin 3-glucoside, quercetin 3-g lucuronide, kaempferol 3-glucoside, kaempferol 3-galactoside, eucryphin, as tilbin and engeletin. Gallic acid 3-beta-glucopyranoside, gallic acid 4-bet a-glucopyranoside and 2-hydroxy-5-(2-hydroxyethyl)phenyl-beta-glucopyranosi de are reported here as natural grape constituents for the first time. (C) 1999 Elsevier Science Ltd. All rights reserved.