HPLC analysis and antioxidant activity of Ulmus davidiana and some flavonoids

In this study, we investigated the antioxidative activities of (−)-catechin (1), (−)-catechin-7-O-β-d-apiofuranoside (2) and (−)-catechin-7-O-β-d-xylopyranoside (3) in terms of their abilities to promote metal chelation, prevent lipid peroxidation, and inhibit DNA cleavage. In addition, high-performance liquid chromatography (HPLC) was used to quantify compounds (1–3) in each of various solvent extracts from Ulmus davidiana.Regarding metal-chelating activity, (−)-catechin (1) exhibited moderate activity at a concentration of 180 μg/ml, with 57.5 ± 0.03% of metal ions chelated. However, (−)-catechin-7-O-β-d-apiofuranoside (2) and (−)-catechin-7-O-β-d-xylopyranoside (3) exhibited weak chelating activity. The values obtained for compounds (2 and 3) were comparable to that of α-tocopherol at a concentration of 180 μg/ml (9.11 ± 0.01%). In addition, (−)-catechin-7-O-β-d-xylopyranoside (3) showed inhibitory activity similar to α-tocopherol (inhibition of lipid peroxidation). Moreover, compounds (1–3) exhibited moderate protective activity against DNA cleavage. These results are consistent with our results for antioxidative activity.