Isolation and identification of α-glucosidase inhibitors from tochu-cha (eucommia ulmoides)

Abstract

α-Glucosidase inhibitory activity was found in aqueous methanol extracts of tochu-cha, dried leaves of Eucommia ulmoides (Eucommiaceae). Five active principles against yeast enzyme were isolated and characterized. Among them, quercetin (1, K j: 8.5 × 10−6 m) was considered to contribute mostly to the activity of the tochu leaves. In regard to an animal α-glucosidase, rat intestinal sucrase activity was also inhibited by 1. © 1997, Taylor & Francis Group, LLC. All rights reserved.