Sesquiterpenes and Lignans From the Branches and Leaves of Wikstroemia micrantha

One new sesquiterpene wikstromicrol (1), 1 new lignan (7R, 8S, 8'S)-9-acetoxyl (-)-isolariciresinol (8), and 12 known compounds were isolated from the branches and leaves of Wikstroemia micrantha. The structures of new compounds were elucidated by extensive interpretation of spectroscopic data and quantum chemical calculations of electronic circular dichroism spectra. The bioactivity assay showed that compounds 6 and 7 had weak cytotoxicity against MCF-7, HCT-116, and HL-60 cell lines with IC₅₀ values ranging from 33.84 to 49.15 µM, whereas compound 8 exhibited moderate cytotoxicity against HCT-116 cell line with an IC₅₀ value of 16.54 µM.