(+)- and (−)-Cajanusine, a Pair of New Enantiomeric Stilbene Dimers with a New Skeleton from the Leaves of Cajanus cajan

A pair of new enantiomeric stilbene
dimers, (+)- and (−)-cajanusine
[(+)-1 and (−)-1], with a unique
coupling pattern were isolated from the leaves of Cajanus
cajan. Their structures including absolute configurations
were elucidated on the basis of comprehensive spectroscopic and single-crystal
X-ray diffraction analyses, as well as CD calculations. The plausible
biogenetic pathway of 1 was also proposed. Additionally,
(±)-1, (+)-1, and (−)-1 exhibited inhibitory activities on the growth of human hepatocellular
carcinoma cells.