Antioxidative and vasodilatory effects of phenolic acids in wine

Phenolic acids represent important fraction of wine phenolics, but their biological effects have been scarcely investigated. We examined the interrelationship between antioxidative capacity and vasodilatory activity, two potentially beneficial biological effects, of nine phenolic acids from wine. The observed antioxidative and vasodilatory effects of the tested phenolic acids were further evaluated through quantitative structure-activity relationship (QSAR) analysis, by using molecular properties, two-dimensional (2D) and three-dimensional (3D) molecular descriptors. The antioxidative capacity of phenolic acids was measured by ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) methods, whereas their vasodilatory activity was determined in the precontracted rat aortic rings. FRAP and TEAC values for antioxidative capacity positively correlated, but antioxidative capacity and maximal vasodilatory effect of the acids showed a negative correlation. This was best illustrated by poor vasodilatory activity of gallic acid, which is the strongest antioxidant among the tested phenolic acids. QSAR study described how antioxidative and vasodilatory effects of phenolic acids relate to the number of hydroxyl groups in the phenyl ring, degree of compactness and branching of molecules, and three-dimensional distributions of atomic polarisability, of the tested molecules. (C) 2009 Elsevier Ltd. All rights reserved.