New lignans from the leaves and stems of kadsura philippinensis

Abstract

Three novel C19 homolignans, taiwankadsurins D (1), E (2) and F (4), and two new C18 lignans kadsuphilins N (3) and O (5) were isolated from the aerial parts of Taiwanese medicinal plant Kadsura philippinensis. The structures of compounds 1-5 were determined by spectroscopic analyses, especially 2D NMR techniques. The structure of compound 5 was further confirmed by X-ray crystallographic analysis. Compounds 1 and 2 have a 3,4-{1'-[(Z)-2''-methoxy- 2''-oxoethylidene]}-pentano(2,3-dihydrobenzo[b]furano)- 3-(2'''-methoxycarbonyl- 2'''-hydroxy-2''',3'-epoxide) skeleton. © 2013 by the authors.