Analysis of trans-resveratrol in grapes by micro-high performance liquid chromatography

Resveratrol, existing in two isomeric trans-and cis-forms, is a phytoalexin that has pharmacological activities, like anti-cancer and anti-cardiovascular diseases as well as life-span increasing properties. Grapes are good sources for resveratrol introduction in the human diet not only directly, but also through its products: wine. In the present work, trans-resveratrol determination and the separation of resveratrol isomers were investigated by the use of micro-high performance liquid chromatography. The analysis conditions were optimized. The baseline separation of trans-and cis-resveratrol was obtained. Further, a trans-resveratrol determination of some grapes growing in Shacheng, Huailai, Hebei province, China was carried out with our analytical method. The concentrations were 6.77 +/- 0.12 and 3.95 +/- 0.18 (microg/g fresh weight) for merlot and cabernet sauvignon grapes, respectively.