Isolation and characterization of endothelium-dependent vasorelaxing compounds from grape seeds

Citation
Df. Fitzpatrick et al., Isolation and characterization of endothelium-dependent vasorelaxing compounds from grape seeds, J AGR FOOD, 48(12), 2000, pp. 6384-6390
Citations number
25
Categorie Soggetti
Agricultural Chemistry","Chemistry & Analysis
Journal title
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN journal
00218561 → ACNP
Volume
48
Issue
12
Year of publication
2000
Pages
6384 - 6390
Database
ISI
SICI code
0021-8561(200012)48:12<6384:IACOEV>2.0.ZU;2-J
Abstract
Previous work has shown that red wines, grape juices, and other grape produ cts cause endothelium-dependent relaxation (EDR) of blood vessels in vitro by increasing nitric oxide production. In this paper we describe the isolat ion and characterization of some of the compounds responsible for EDR activ ity. Concord grape seeds were extracted with methanol and the compounds wer e separated by Toyopearl TSK HW-40S chromatography. Resulting fractions (pr imarily phenolic acids, catechins, and proanthocyanidins) were further sepa rated semipreparatively by reversed-phase HPLC, and peaks were collected an d bioassayed for EDR activity using the rat aorta preparation. EDR-active c ompounds were subsequently characterized by HPLC retention times and electr ospray-ion-trap mass spectrometry. The compounds exhibiting the most EDR ac tivity were proanthocyanidin trimers, tetramers, pentamers, and polymers an d their gallates, as well as a dimer gallate (EC50 values in the range of 0 .6-2.5 mug catechin equivalents/mL). These compounds should be useful for i n vitro and in vivo studies, particularly as they relate to improvement of cardiovascular function.