Abstract: In the course of our study of bioactive natural products from Schisandra plants, we isolated a neolignan from an EtOAc extract of the stems of Schisandra propinqua (Wall.) Baill. The structure of the new compound was determined to be 4, 4-di (4-hydroxy-3-methoxyphenly)-2, 3-dimethylbutanol (compound 1) on the basis of 1H- and 13C-NMR spectra and 2D NMR methods. Eight known compounds, compounds 2–9, were also isolated and identified, of which compounds 3, 4, 6 and 9 were isolated for the first time from this plant. In addition, compounds 1–4 were evaluated for cytotoxicity by an 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Compound 1 showed significant potential cytotoxic ability in the bioassay.Authors for correspondence. Shi-Lin Chen: Tel: +86 (0)755 2673 7179; E-mail: bcslchen@inet.polyu.edu.hk; Pei-Gen Xiao: Tel: +86 (0)10 6301 1294; E-mail: xiaopg@public.bta.net.cn

Key words: cytotoxicity, lignan, Schisandra propinqua, Schisandraceae.