Simple high-yield purification of 3,4,5-tri-O-caffeoylquinic acid from sweetpotato (Ipomoea batatas L.) leaf and its inhibitory effects on aldose reductase

Abstract

A simple high-yield method for purifying 3,4,5-tri-O-caffeoylquinic acid from sweetpotato leaves (Ipomoea batatas L.) was established. The method consisted of methanol extraction, water-hexane partition, MCI gel CHP20P, and Sephadex LH-20 chromatography. All purification steps required fewer than 3 days, and the yield of purified 3,4,5-tri-O-caffeoylquinic acid was calculated to exceed 76 mg from 100 g of leaf powder. Its recovery was estimated to be more than 66%, and its purity more than 98%. The aldose reductase inhibitory activities of these derivatives were 3,4,5-tri-O-caffeoylquinic acid > 3,4-di-Ocaffeoylquinic acid = 3,5-di-O-caffeoylquinic acid > 4,5-di-O-caffeoylquinic acid > 5-O-caffeoylquinic acid. These results indicate that 3,4,5-tri-O-caffeoylquinic acid is the more bioactive component, and this purification method enables in vivo experiments.