Chemical constituents from Schisandra perulata and their cytotoxic activity.

• Two new compounds, schisandrulatas A and B were isolated from Schisandra perulata. • The structures were successfully determined by spectroscopic evidence. • Compounds 1 , 4 , 7 , and 9 showed potent cytotoxic activity against CAL27 cancer cell line. • Compounds 1 , 4 , 7 , and 9 exhibited potent cytotoxic activity against MDA-MB231 cancer cell line. Two new compounds, schisandrulata A (1) and schisandrulata B (5), and nine known compounds, 6- O -benzoylgomisin O (2), kadsutherin (3), γ -schizandrin (4), pinotatol (6), schisphentetralone A (7), (–)-8′-epi-aristotetralone (8), (–)-8,8′-epi-aristotetralone (9), rel-(8 R ,8′ R)-dimethyl-(7 S ,7′ R)-bis(3,4-methylenedioxyphenyl)tetrahydrofuran (10) and (-)-machilusin (11) were isolated from the leaves of Schisandra perulata Gagnep. Their chemical structures were determined by means of HR-ESI-MS, NMR, and CD spectra. All the compounds were evaluated for their cytotoxic activity against the human oral cancer (CAL27) and human breast cancer (MDA-MB231) cell lines. Compounds 1 , 4 , 7 , and 9 showed potent cytotoxic activity against CAL27 cell line with IC 50 values of 1.8 ± 0.2, 1.2 ± 0.1, 1.2 ± 0.2, and 2.0 ± 0.1 μM, respectively, indicating that they have stronger cytotoxic activity than that of the positive control capecitabine (IC 50 value of 8.20 ± 0.75 μM). Similarly, compounds 1 , 4 , 7 , and 9 also exhibited potent activity against the MDA-MB231 cell line with IC 50 values of 3.5 ± 0.1, 1.80 ± 0.2, 0.9 ± 0.2, and 3.4 ± 0.3 μM, respectively. These results indicated that compounds 1 , 4 , 7 , and 9 could be potential anticancer reagents for further drug discovery research. [ABSTRACT FROM AUTHOR]