Five new phenolic compounds with antioxidant activities from the medicinal insect Blaps rynchopetera

Abstract

Five new phenolic compounds rynchopeterines A–E (1–5), in addition to thirteen known phenolics, were isolated from Blaps rynchopetera Fairmaire, a kind of medicinal insect utilized by the Yi Nationality in Yunnan Province of China. Their structures were established on the basis of extensive spectroscopic analyses (1D and 2D NMR, HR-MS, IR) along with calculated electronic circular dichroism method. Rynchopeterines A–E (1–4) exhibited significant antioxidant activities with IC50 values of 7.67–12.3 µg/mL measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Besides, rynchopeterines B (2) and C (3) showed mild cytotoxicity against tumor cell Caco-2 and A549.