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.