Phytochemical investigation of root barks OFSecuridaca longipedunculata and evaluation of its antibacterial activities

Abstract

The discovery of new antimicrobial compounds from medicinal plants mainly from those which have documented traditional uses is encouraging and believed to solve these microbial burdens. Therefore, the aim of this study was to isolate and characterize antimicrobial compounds from the root bark of Securidaca longipedunculata, aplant commonly used for the treatment of sexually transmitted disease, fungal infection, and wounds in Ethiopia. The dried and powdered root bark was extracted with increasing gradient solvent (hexane, chloroform, acetone and methanol) about 5 g (0.53%), 12.5 (1.32%), 10 (1.05%), 40 g (4.23%) of crude extract of nhexane, chloroform, acetone, and methanol, respectively were obtainedand screened for antibacterial activity on four pathogenic bacterial strain and phytochemical analysis was carried out to determine the secondary metabolites in each extract.Phytochemical screening revealed that terpenoids, coumarins and Saponins are present in the entire crude extracts, alkaloids and quinone were present in acetone and methanol extract only, and phenols and flavonoids were present in all the extract except hexane extract. The acetone extract was subjected to column chromatography for further purification using ethyl acetate and n-hexane.The first fraction afforded 12 mg of compound 1, the second fraction afforded 13 mg compound 2 and the third fraction afforded 20 mg compound 3.The isolated compounds were characterized by the various spectral techniques: IR, UV, 1 H NMR, 13 C NMR, DEPT-135, HMBC and HSQC. The antibacterial analysis showed that the acetone extract was the most active with the mean zone of inhibition30mmfollowed by methanol extract 28mm, chloroform 16 mm and hexane extract 8 mm respectively. Compound 3showed moderate antibacterial activity with 12 mm zone of inhibition.These results verified the claims by traditional healers inEthiopia to treatedifferent disease using this plant.