Pterocarpans and triterpenoids from Gueldenstaedtia verna

Two new pterocarpan glycosides (1-2), five new triterpenoids (3-7), and 13 known analogues (14-20) were isolated from the whole plants of Gueldenstaedtia verna. These new compounds (1-7) were elucidated by extensive spectroscopic techniques including 1D (¹H and ¹³C) and 2D NMR experiments (COSY, HSQC, HMBC and NOESY), HR-ESI-MS and chemical methods. The absolute configuration of 1 was established by the optical rotation, the comparison of experimental and calculated electronic circular dichroism (ECD) spectra and an X-ray diffraction analysis. All the isolates were evaluated for their cytotoxicities against four human cancer cell lines and inhibitory activities on LPS-induced NO production in RAW264.7 cells.