Triterpenoid saponins from the seeds of Caragana microphylla.

Two new triterpenoid saponins, namely caraganoside C (1) and caraganoside D (2), were isolated from the seeds of Caragana microphylla. Their structures were elucidated on the basis of spectroscopic analyses, including homo- and hetero-nuclear correlation NMR experiments (COSY, HSQC and HMBC). Both 1 and 2 exhibited moderate inhibitory activity against NO production in LPS-stimulated RAW264.7 cells with IC(50) values of 26.4 µM and 32.2 µM, respectively. In addition, 1 showed weak cytotoxicity against MCF-7, HL-60, HCT116, and A549 cell lines.