Two new flavonoids from the seeds of Derris scandens

Two new flavonoids, (2 S)-3′,4′,5′-trimethoxyflavanone (1) and 2′-hydroxy-2,4-dimethoxy-4′- O-[( E)-3,7-dimethyl-2,6-octadienyl]chalcone (2), together with a known pterocarpene, flemichapparin B (3), and a known rotenoid, dehydrodeguelin (4), were isolated from the seeds of Derris scandens. Their structures were determined by means of extensive 1D and 2D NMR spectral studies.