Lignans with NO inhibitory activity from Tinospora sinensis.

Two new lignan glucosides, tinsinlignans A and B (1 and 2), two new oxyneolignans, tinsinlignans C and D (3 and 4), along with one known analogue (5), were isolated from the stems of Tinospora sinensis. The structures of the new compounds were elucidated based on analysis of spectroscopic data, and the absolute configuration of 1 was determined through electronic circular dichroism (ECD) calculation based on the time-dependent density functional theory (TD-DFT). Compounds 1-4 were evaluated for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine RAW264.7 macrophage cells and compounds 1 and 2 exhibited moderate inhibitory activities with IC50 values of 18.5 ± 2.0 and 28.8 ± 1.2 μmol·L-1, respectively.