Sesquineolignan and neolignan enantiomers from Triadica sebifera

Two pairs of new sesquineolignan enantiomers (1a/1b and 1c/1d), two pair of new 4′,7-epoxy-8,3′-neolignan enantiomers (2a/2b and 3a/3b), and a pair of new 3′,7-epoxy-8,4′-oxyneolignan enantiomers (4a/4b), along with two pairs of known 4′,7-epoxy-8,3′-neolignan enantiomers (5a/5b and 6a/6b), were obtained from the stems and leaves of Triadica sebifera. The structures of the enantiomers were elucidated by spectroscopic analyses, and their absolute configurations were assigned by the experimental ECD spectra. Among them, compounds 5b, 6a and 6b showed inhibitory activities against NO production in activated microglial BV-2 cells, with IC50 values of 14.3, 23.2 and 33.3 μM, respectively.