2-Arylbenzofuran derivatives from Morus wittiorum

The investigation on the stem bark of Morus wittiorum was carried out to find its chemical constituents possessing anti-oxidative activity. The isolation and purification were performed by various chromatographies such as silica gel, Sephadex LH-20, RP-C18 column chromatography and so on. Based on the spectral analysis such as NMR, MS, etc., seven 2-arylbenzofuran derivatives were identified as wittifuran D (1), wittifuran E (2), moracin C (3), moracin M (4), moracin P (5), 2-(3,5-dihydroxyphenyl)-5,6-dihydroxybenzofuran (6) and mulberroside C (7). Compounds 1-7 were isolated from this plant for the first time. Among them, 1 and 2 were new compounds. Compounds 3-7 were used to assay antioxidant activity, the inhibitory ratios of compounds 3, 4, 6, at a concentration of 1×10^-5 mol·L^-1, to malondialdehyde (MDA) produced during microsomal lipid peroxidation induced by ferrous-cysteine were 73%, 69% and 89% respectively.