Two new lignans from the aerial parts of Saururus chinensis with cytotoxicity toward nasopharyngeal carcinoma

Two new lignans (1 and 12), together with 15 known compounds (2-11 and 13-17), were isolated from the aerial parts of Saururus chinensis Baill. Their structures were determined through extensive spectroscopic analyses. All the isolates were evaluated for their cytotoxicity against four human nasopharyngeal carcinoma cells (HONE1, CNE1, CNE2, and SUNE1). Compound 13 showed the most potent cytotoxicity toward HONE1, SUNE1, CNE2, and CNE1 cells with IC50 values of 0.76, 5.42, 5.86 and 6.28 mu M, respectively. Further studies revealed that compound 13 suppressed cell growth by arresting the cell cycle at the S phase and induced cell apoptosis in the HONE1 cell line.