Heteroclitins N – Q, New Compounds from Stems of Kadsura heteroclita ( Roxb .) Craib

From the stems of Kadsura heteroclita ( Roxb .) Craib , a new novel C 19 homolignan, heteroclitin N ( 1 ), as well as three new lignans, heteroclitins OQ ( 2 – 4 ), were isolated. Their structures were elucidated based on spectral analysis, including 1D and 2D NMR experiments. There is an additional spirocyclic oxirane system in heteroclitin O ( 2 ), which is the first example of a lignan with an oxirane ring in a spirobenzofuranoid dibenzocyclooctene structure in the genus Kadsura.