Oxygenated lignans from the fruits of Schisandra arisanensis.

An acetone extract of the fruits of the Taiwanese medicinal plant Schisandra arisanensis has yielded 11 new oxygenated lignans. Four of these, named arisantetralones A-D (1-4), possess the aryltetralone skeleton, while the other seven, named arisanschinins F-L (5-11), are polyoxygenated C(18)-dibenzocyclooctadiene lignans. Structures were determined on the basis of spectroscopic analyses, especially 2D-NMR techniques. The structure of compound 1 was confirmed by X-ray crystallographic analysis. Immunomodulatory activity of the isolated lignans was tested and evaluated.