ABSTRACT
Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1-2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C.thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1-7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4-7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model.
Subject(s)
Arginase/antagonists & inhibitors , Cyperus/chemistry , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Animals , Aorta, Thoracic/drug effects , Arthritis, Experimental/drug therapy , Arthritis, Experimental/physiopathology , Benzofurans/chemistry , Benzofurans/isolation & purification , Benzofurans/pharmacology , Calamus , Cattle , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiopathology , Enzyme Inhibitors/isolation & purification , Flavonoids/chemistry , Flavonoids/isolation & purification , Flavonoids/pharmacology , In Vitro Techniques , Magnetic Resonance Spectroscopy , Male , Methanol , Molecular Structure , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Rats , Resveratrol/chemistry , Resveratrol/isolation & purification , Resveratrol/pharmacology , Stilbenes/chemistry , Stilbenes/isolation & purification , Stilbenes/pharmacology , Vasodilator Agents/chemistry , Vasodilator Agents/isolation & purification , Vasodilator Agents/pharmacologyABSTRACT
The impact of water deficit on stilbene biosynthesis in wine grape (Vitis vinifera) berries was investigated. Water deficit increased the accumulation of trans-piceid (the glycosylated form of resveratrol) by 5-fold in Cabernet Sauvignon berries but not in Chardonnay. Similarly, water deficit significantly increased the transcript abundance of genes involved in the biosynthesis of stilbene precursors in Cabernet Sauvignon. Increased expression of stilbene synthase, but not that of resveratrol-O-glycosyltransferase, resulted in increased trans-piceid concentrations. In contrast, the transcript abundance of the same genes declined in Chardonnay in response to water deficit. Twelve single nucleotide polymorphisms (SNPs) were identified in the promoters of stilbene synthase genes of Cabernet Sauvignon, Chardonnay, and Pinot Noir. These polymorphisms resulted in eight changes within the predicted cis regulatory elements in Cabernet Sauvignon and Chardonnay. These results suggest that cultivar-specific molecular mechanisms might exist that control resveratrol biosynthesis in grapes.
Subject(s)
Fruit/metabolism , Plant Extracts/metabolism , Stilbenes/metabolism , Vitis/metabolism , Water/metabolism , Acyltransferases/genetics , Acyltransferases/metabolism , Fruit/chemistry , Fruit/enzymology , Fruit/genetics , Plant Extracts/analysis , Plant Proteins/genetics , Plant Proteins/metabolism , Polymorphism, Single Nucleotide , Stilbenes/analysis , Vitis/chemistry , Vitis/enzymology , Vitis/geneticsABSTRACT
Three new monomeric stilbenoid glucosides, (Z)- and (E)-resveratrol 3,5- O-beta-diglucosides (1 and 2, respectively) and (Z)-resveratrol 3,5,4'- O-beta-triglucoside (3), were isolated from an extract of Vitis vinifera cell cultures (Cabernet Sauvignon) together with the known (E)- and (Z)-piceids and (E)- and (Z)-resveratrol 3,4'- O-beta-diglucosides that have already been identified in a Gamay cell culture extract. The structure determinations were based on spectroscopic data analysis.