Lignans from the Twigs of Euonymus alatus ( Thunb .) Siebold and Their Biological Evaluation

A new sesquilignan, euonymolin A ( 1 ), and six known lignans, (−)‐de‐ O ‐methylmagnolin ( 2 ), (+)‐de‐ O ‐methylepimagnolin A ( 3 ), (+)‐syringaresinol ( 4 ), (+)‐pinoresinol ( 5 ), (+)‐medioresinol ( 6 ), and (+)‐lariciresinol 4′‐ O ‐ β ‐ d ‐glucopyranoside ( 7 ), were isolated from the twigs of Euonymus   alatus ( Thunb .) Siebold (Celastraceae). The structures of the isolated compounds were elucidated based on spectroscopic analyses, including extensive 1D‐ and 2D‐ NMR techniques, HR ‐ MS analysis and circular dichroism ( CD ) data, and the literature data. All of the isolated compounds were evaluated for antiproliferative activity against A549, SK ‐ OV ‐3, SK ‐ MEL ‐2, and HCT ‐15 cell lines and inhibition of nitric oxide ( NO ) production in a lipopolysaccharide ( LPS )‐activated BV 2 cell line. All compounds showed cytotoxicity against the SK ‐ MEL ‐2 cell line with IC 50 values of 23.24 – 48.14 μ m and inhibited NO production in LPS ‐activated BV ‐2 cells with IC 50 values of 6.75 – 23.53 μ m .