Resveratrol in Parts of Vine and Wine Originating from Bohemian and Moravian Vineyard Regions

Abstract

SUMMARY Chemically, resveratrol is a substance of a polyphenolic character from the group of phytoalexins – 3,5,4’- trihydroxystilbene – and exists in cis and transisomer forms. In natural sources trans-isomer is more common. As a natural polyphenolic substance, it shows a whole range of biological activities, such as anti-oxidizing and anti-microbial features (namely anti-fungal activities), the ability to absorb free radicals, affects blood sedimentation rate etc. Recently, trans-resveratrol has also been attributed anti-mutagen and chemo-protective features against cancer proliferation. It is assumed that resveratrol could be one of the active substances contributing to the health benefits, namely it decreases the risk of cardiovascular diseases through a reasonable consumption of red wine. Grapes of Vitis vinifera and especially red wine represent its main source in human diet. Grape peels contain about 0.5 to 2.0 mg of resveratrol/g of dry weight and the average concentration in red wines of world provenience fluctuates between 1.0 and 3.0 mg/l. Resveratrol was determined by HPLC method with electrochemical detection after direct injection of wine or plant extracts. As expected, red wines from vines originating in the Bohemian and Moravian vineyard regions appeared to contain relatively high levels of resveratrol (from 1.3 to 15.4 mg/l) and trans/ cis ratio ranged from 0.5 to 4.8, excess of cis-resveratrol to trans-isomer was typical for red wine growing in Most region (northern Bohemia) where vineyards are exposed to higher environmental stress due to frequent air pollutions in this area. In addition, resveratrol determined in different parts of grapevine (leaves, rachis) varied from 6 to 490 mg/kg of the dry matter. Cluster stems were found as the richest source of resveratrol.