One new alkaloid, together with 10 known compounds were isolated from the aerial parts of Chelidonium majus L. by repeated silica gel column chromatography. Their chemical structures were elucidated on the basis of physicochemical and spectroscopic data. Among them, 6-acetonyldihydrochelerythrine (4), 6-acetonyldihydrosanguinarine (5), 6-ketenesanguinarine (6), demethylchelerythrine (7) and demethylsanguinarine (11) were isolated for the first time from this plant. Compound 6 was identified as a new compound. These compounds were screened for cytotoxicity against human non-small lung carcinoma (H1299), breast cancer (MCF-7) and liver cancer (SMMC-7721). In a series of cytotoxic tests, compounds 9 and 10 displayed potent cytotoxic activity against H1299, MCF-7 and SMMC-7721, with the IC50 values of 8.16-35.25 μg/mL.
Keywords: 6-ketenesanguinarine; Chelidonium majus L.; cytotoxic activity.