Heteroclitins R-S:new dibenzocylooctadiene lignans from Kadsura heteroclita

AIM:To study the dibenzocylooctadiene lignans from the stems of Kadsura heteroclita.METHOD:Chromatographic separations of silica gel and semi-preparative HPLC were used.All of the structures were elucidated on the basis of spectroscopic analysis,including 2D-NMR and HR-MS techniques.RESULTS:Four dibenzocylooctadiene lignans were isolated from K.heteroclita.Their structures were identified as heteroclitin R(1),heteroclitin S(2),gonisin O(3),and schisanlignone A(4).CONCLUSION:Heteroclitin R(1) and heteroclitin S(2) are new natural lignans.