A new carbamate with cytotoxic activity from the aerial parts of Siegesbeckia pubecens

AIM: To study the chemical constituents of Siegesbeckia pubescens. METHODS: The chemical constituents were isolated by extraction, crystallization and various chromatographic methods, and the chemical structures were elucidated on the basis of spectral analysis. In addition, the cytotoxic activity of compound 1 was evaluated using human lung cancer cell A 549. RESULTS: Four compounds were obtained, and their structures were identified as (E)-3-(3-oxobut-1-enyl)phenyl dimethylcarbamate (1), ent-2-oxo-15, 16, 19-trihydroxypimar-8(14)-ene (2), 16-acetylkirenol (3), 3, 7-dimethylquercetin (4). CONCLUSION: Compound 1 is a new carbamate, and the IC50 in MTT method of compound 1 was 58 gmL-1.