A new tetrastilbene named carasinol D (1) was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B (2) by an acid-catalyzed conversion.
Three stilbene tetramers, carasinols AC (13), along with three known substances, leachianol C, cararosinol A and stenophyllol B, were isolated from the roots of Caragana sinica. Their structures were elucidated by spec-troscopy. It was found that compounds isolated except for stenophyllol B stimulated the proliferation of cultured osteoblasts.