Lignans and coumarins from the stem bark of Alyxia fascicularis (Wall. ex G. Don) Benth. ex Hook. f.).

In the first phytochemical investigation of specialized metabolites from the stem bark of Alyxia fascicularis, which is used in different traditional medicines, including those of Myanmar and China, five lignans (1-5) and three coumarins (6-8) were isolated by semipreparative HPLC separations and identified mainly by 1D and 2D NMR spectral analysis. The radical scavenging activity of isolated compounds was tested using the DPPH method. Noteworthy, most lignans exhibited antiradical effects comparable to vitamin C and gallic acid. Instead, compounds 1-8 showed no cytotoxic effect on Hela cell line. A possible biosynthetic pathway to enantiomeric 3 and 4 is suggested.