Characterization of antioxidant compounds in Eriobotrya fragrans Champ leaf

Both loquat (Eriobotrya fragrans Champ) fruits and leaves are often used as important ingredients in Chinese herbal formulations for medicinal treatments against cough and asthma, but little information is available about the inherent bioactive chemicals. In this study, 11 major compounds were identified from the acetic ether extract of leaves of the fragrance flower loquat. These chemicals are (1) 2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid, (2) 2α-hydroxyursolic acid, (3) ursolic acid, (4) 2α-hydroxyoleanolic acid, (5) tormentic acid, (6) β-daucosterol, (7) epicatechin, (8) cinchonain Ia (9), cinchonain Ib, (10) quercetin-3-O-α-l-rhamnoside and (11) arbutin. Meanwhile, the antioxidant activities of these compounds were evaluated by the DPPH and FRAP assays. Cinchonain Ib exhibited the highest antioxidant activity, followed by cinchonain Ia, epicatechin, quercetin-3-O-α-l-rhamnoside and arbutin.