Ultrasound-assisted extraction of resveratrol from grape leaves and its purification on mesoporous carbon.

Resveratrol has been extracted from grape leaves by ultrasound-assisted extraction with aqueous ethanol and further concentrated on a column of mesoporous carbon. The ethanol concentration, extraction temperature, solid/liquid ratio, and extraction time have been investigated, and the extraction kinetics has been studied. After one treatment run with mesoporous carbon, the resveratrol purity was improved from 2.1 to 20.6%. The antioxidant activities of grape leaf extracts before and after concentration have been analyzed. Mesoporous carbon has been applied in the purification of resveratrol from grape leaves for the first time, and it is shown to offer a promising procedure in this field. Grape leaf is a promising material for the extraction of resveratrol, which shows antioxidant properties.