dc.description.abstract | The present study designed to investigate the quantitative distributions in the secondary metabolites and biological activity of sub-fractions obtained successively from water and methanol: dichloromethane (rate 1:1; v:v) solvent decoction of Diplotenia bingolensis aerial parts. The crude extracts were obtained from the aerial parts of the endemic D. bingolensis species refluxing with water and organic solvents. Sub-fractions of water extract were obtained by successive fractionation of the water extract with hexane (WH), dichloromethane (WD), ethyl acetate (WE) and n-butanol (WB), respectively. Sub-fractions of organic solvent were obtained by fractionation of the organic crude extract with hexane (OH), dichloromethane (OD), ethyl acetate (OE), n-butanol (OB) and water (OW), respectively. The total amount of phenols and flavonoids contained in each sub-fraction was analyzed by UV-VIS spectrophotometer, analysis of lipophilic components by GC–MS spectrometer, and quantitative analysis of hydrophilic components by HPLC-TOF/MS spectrophotometer. Furthermore, the biological activity of each sub-fraction was compared with different antioxidant activities such as DPPH radical scavenging activity and ferric ion reduction capacity. Sub-fraction WD (137.1 ± 2.1 μg QE/mg DI) and OE (127.1 ± 5.2 μg QE/mg DI) in terms of flavonoid content, sub-fraction WD (665.8 ± 47.6 μg GAE/mg DI) and OE (724.6 ± 43.6 μg GAE/mg DI) were the richest isolates in terms of total phenol content. Sub-fractions OH and OD contained linoleic acid (17.0 and 11.0%, respectively) and linolenic acid (22.1 and 18.5%, respectively). It was revealed that sub-fractions were rich in terms of rutin (1.2–47.2 μg HC/mg DI) and chlorogenic acid (0.1–12.1 μg HC/mg DI). Sub-fractions WD and OE were showed the highest DPPH radical scavenging activity with 46.4 ± 1.4 and 47.6 ± 10.0 μg/mL EC50 values, respectively. This study is the first to demonstrate biological insight of the potential antioxidant activity of D. bingolensis. These findings warrant the popular use of the endemic D. bingolensis and highlight the potential of its active constituents in the development of new antioxidative drugs. © 2019 | |