LC-MS guided isolation of antibacterial and cytotoxic constituents from Clausena anisata

Phytochemical investigation of leaves and stem bark extracts of Clausena anisata monitored by liquid chromatography high-resolution mass spectrometry (LC-HR-MS) analysis led to the isolation and characterization of twenty-one secondary metabolites: four carbazole alkaloids (1-4) including one new name clausamine H (1), fourteen coumarins (5-18), two porphyrin derivatives (19-20), and one limonoid (21). Crude extracts were analyzed first by LC-HR-MS, and target compounds were isolated by a multi-step separation procedure using column chromatography and preparative high-performance liquid chromatography (prep-HPLC) monitored by LC-HR-MS analysis. The structures of isolates were determined by means of spectroscopic and spectrometric data, as well as by comparison with literature values. The isolates showed weak to high antibacterial activities with imperatorin (14) being the most active one. Cytotoxic activities against HeLa and monkey Vero cells were also investigated, and murrayamine-A (4), 3-(1,1-dimethyl allyl) xanthyletin (5) gravelliferone (7), excavatin D (10), 7-[(E)-7-hydroxy-3,7-dimethylocta-2,5-dienyloxyl]-coumarin (13), phellopterin (15), and 1-O-methylclausenolide (21) were found active with LC50 values ranged from 1.14 to 3.26 A mu g/mL and a good selectivity index values (SI 38.20-231.58) against the HeLa cells. However, these compounds were non-toxic to normal cells indicating their high potential to be used as anticancer drug.