Two new oligostilbenes from Caragana sinica.

A new resveratrol dimer, carasiphenol A (1), and a new resveratrol trimer, carasiphenol B (2), have been isolated from the aerial parts of Caragana sinica. Their structures have been elucidated from spectroscopic evidence, especially HMBC and NOE experiments. The relative configuration of the known dimer pallidol (6) was confirmed by X-ray diffraction.