Phytochemical Investigation of Root of Clausena anisata for Antibacterial Activity

Abstract

Clausena anisata is one of the medicinal plants used traditionally for treatment of parasitic infections, irritation (boils, ringworm and eczema), wound, pains, flat worm infestations, influenza and constipation. The present study focused on the extraction, isolation, characterization of the chemical constituents and evaluation of antibacterial activities on the roots extracts of Clausena anisata plant using maceration extraction technique. The powdered roots (500g) of Clausena anisata were successively extracted with dichloro methane/methanol and methanol (2.5L) to furnish extracts with percentage yields of 1.7% and 2.48%, respectively. Phytochemical screening test of dichloromethane/methanol (1:1) and methanol roots extract revealed the presence of flavonoids, phytosterols, coumarins, phenols, alkaloids, tannins, terpenoids and free reducing sugars whereas saponins were absent. Silica gel column chromatographic separation of the dichloromethane/methanol extract afforded three coumarins namely Graveliferone (15), Imperatorin (16), Chalepin (17) and a carbazole alkaloid Heptaphyline (14). Structures of the compounds were elucidated using the spectroscopic techniques (IR, 1H NMR, 13C NMR, and DEPT-135) and comparison with literature data. Antibacterial activity of the crude extracts and isolated compounds were screened using agar diffusion method against strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus substilis. The results of antibacterial activity tests revealed Heptaphyline (14) and Imperatorine (16) exhibited comparable antibacterial activity against S. aureus and B. substilis (14 and 13 mm zone of inhibition, respectivily) to that of Ciprofloxacin (15 mm zone of inhibition) at a concentration of 20µg/mL. Compound 17(Chalepin) revealed more antibacterial activity against B. substilis (16mm zone of inhibition) compared to Ciprofloxacin (15 mm). The results obtained substantiate the traditional use of this plant against bacteria