Three new dibenzocyclooctadiene lignans, marlignans M-O (1-3), together two known ones, were isolated from the leaves and stems of Schisandra wilsoniana. The structures of 1-3 were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compound 2 showed anti-HIV-1 activity with an EC50 value of 5.82 mu g/mL and a therapeutic index (TI) of more than 12.8. Compound 3 showed obvious bioactivity in inhibiting Epstein-Barr virus early antigen (EBV-EA) activation.
Dietary lignans are phyto-oestrogens that possibly influence human health. The present review deals with lignan bioavailability, the study of which is crucial to determine to what extent metabolism, absorption and excretion of lignans alter their biological properties. Since intestinal bacteria play a major role in lignan conversion, for instance by producing the enterolignans enterodiol and enterolactone, emphasis is put on data obtained in recent bacteriological studies. Phyto-oestrogens: Lignans: Enterolignans: Bioavailability: Human intestinal microbiota
Five new dibenzocyclooctadiene lignans, named gomisin A (2), B (3), C (4), F (5) and G (6), were isolated from the petroleum ether extract of fruits of Schizandra chinensis BAILL. (Schizandraceae) and their absolute structures were elucidated by chemical and spectral techniques. The absolute structure of schizandrin (1), the plane structure of which had already been elucidated by Kochetkov et al., was also elucidated on the basis of spectroscopic results.