Six undescribed derivatives of stilbene isolated from Lindera reflexa Hemsl. and their anti-tumor and anti-inflammatory activities.

Six undescribed stilbene derivatives Reflexanbene DH (1-4, 6) and Reflexanbene J (5), as well as one known stilbene 3,5-dimethoxystilbene (7), were isolated from the dried roots of Lindera reflexa Hemsl. Their structures and absolute configurations were elucidated using spectroscopy and electronic circular dichroism (ECD) analysis. In cytotoxic assays, moderately inhibitory activities of Reflexanbene F (3) against MGC80-3 and A549 cell lines were observed, with IC50 values of 15.42 and 5.09 µM, respectively. The IC50 value of Reflexanbene E (2) on A549 cell lines was 19.78 µM. The isolated compounds were also tested for their inhibitory effect against LPS-induced NO and IL-6 production in RAW 264.7 cells. In particular, Reflexanbene J (5) and Reflexanbene H (6) showed significant inhibition of NO production in LPS-stimulated macrophage RAW 264.7 cells at the concentration of 20 µM. Furthermore, the expression of IL-6 protein in the LPS-induced RAW 264.7 cells can also be significantly inhibited by different concentrations (5, 10 and 20 µM, p < 0.05 or p < 0.01) of compounds 1-7.

Isolation and cytotoxic activity of selaginellin derivatives and biflavonoids from Selaginella tamariscina.

Five selaginellin derivatives, including two new selaginellins termed selaginellins M (1) and N (2), and three previously identified compounds, selaginellin (3), selaginellin A (4), and selaginellin C (5), were isolated from the Selaginella tamariscina (Beauv.) Spring plant. In addition, four known biflavonoids, namely neocryptomerin ( 6), hinokiflavone (7), pulvinatabiflavone (8), and 7''- O-methylamentoflavone (9), were also isolated. The structures of new compounds 1 and 2 were elucidated by spectroscopic analysis. The cytotoxic activity of compounds 1- 9 was evaluated against a small panel of human cancer cell lines, including U251 (human glioma cells), HeLa (human cervical carcinoma cells), and MCF-7 (human breast cancer cells). The two new selaginellins, selaginellins M (1) and N (2), showed medium activity against the human cancer cell lines.