A Known Naphthalene, Isoeleutherol, from the Herb of Lygodium microphyllum

A known naphthalene, isoeleutherol (1), was isolated from the herb of Lygodium microphyllum. The chemical structure of 1 was determined on the basis of spectroscopic data mainly UV, IR, HRTOFMS, 1D- and 2D-NMR spectroscopy, as well as by comparing with compounds previously reported. Isoeleutherol was isolated from this plant for the first time and showed moderate antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) with IC50 value of 53.96 ± 2.87 µg/mL