Antioxidant properties of Cortex Fraxini and its simple coumarins |
| |
Authors: | Chi-Rei Wu Mei-Yueh Huang Yung-Ta Lin Heng-Yin Ju Hui Ching |
| |
Affiliation: | 1. Institute of Chinese Pharmaceutical Sciences, Department of Pharmacy, China Medical University, 91, Hsueh Shih Road, Taichung 40424, Taiwan, ROC;2. Department of Pharmacy, Show-Chwan Memorial Hospital, 542, Chung-shan Road, Changhua, Taiwan, ROC;3. Department of Pharmacy, Wei-Gong Memorial Hospital, 128, Xinyi Road, Miaoli, Taiwan, ROC;4. Department of Pharmacy, Taichung Hospital, Department of Health, The Executive Yuan, 199, San Min Road, Taichung, Taiwan, ROC |
| |
Abstract: | We present the antioxidant properties of crude extract, fractions and ingredients of Cortex Fraxini (CF) and compare the antioxidant capacities of coumarin ingredients of CF and known antioxidants, including catechin, quercetin, ascorbic acid, trolox and BHT. The IC50 values for CF in the DPPH and TEAC methods were 406 and 39.3 μg/ml, respectively. Among all fractions the chloroform fraction is the most active fraction in scavenging DPPH, ABTS and hydroxyl radicals, and there is a significant relationship between the antioxidant activities and the contents of the antioxidant phenolic ingredients. The contents of esculetin and fraxetin in the chloroform fraction were 8.44% and 11.1%, respectively. Esculetin and fraxetin also had good radical-scavenging capacities, and esculetin was the best, among all test compounds, against the DPPH radical. Moreover, esculetin and fraxetin had selective scavenging activity upon hydroxyl radicals and hydrogen peroxide, and this potency was better than known antioxidants and equal to quercetin in scavenging hydrogen peroxide. These results show that CF, partitioned with chloroform, gave a phenolic coumarin-enriched fraction, and that this fraction had the best free radical-scavenging activity and inhibition of Fe2+/ascorbate-induced lipid peroxidation, mainly due to its reducing power. |
| |
Keywords: | Cortex Fraxini Coumarins Antioxidant activity DPPH method TEAC assay Active oxygen scavenging capacity |
本文献已被 ScienceDirect 等数据库收录! |
|