Novel benzophenone with antiradical activities from the aerial parts of Hypericum lancasteri

Abstract

A novel benzophenone lancasteriphenone A (1), one new natural product 2,4-dihydroxy-6-(3-methylbut-2-enoxy) phenyl]-phenylmethanone (2), along with two known compounds (3 and 4) were isolated and identified from the aerial parts of Hypericum lancasteri. Their structures were elucidated by means of spectroscopic techniques. Novel compound 1 possessed a benzophenone skeleton with a farnesyl side chain. DPPH radical scavenging activities were tested to determine the antioxidant potential of the methanol extract, dichloromethane extract as well as the isolated compounds (1–4). Its methanol and dichloromethane extracts exhibited significant antiradical effect with IC50 values of 20.84 µg/mL and 60.63 µg/mL, respectively. Besides, the antiradical activitise of the compounds 1–4 from active dichloromethane extract were also tested. The DPPH radical scavenging rates of the compounds 1–4 were 33.07%, 24.59%, 17.67% and 86.56% at the concentration of 400 µmol/L, respectively, while the IC50 value (97.53 µmol/L) of compound 4 was closest to that of the positive control drug ascorbic acid (IC50 = 58.13 µmol/L). This work provided systematic biological targeted study on antioxidant activity from active extracts to novel compound, and shed a new light on the further antioxidant application research of H. lancasteri.