PHYTOCHEMICAL PROFILING AND ANTIBACTERIAL ACTIVITY OF THE NONPOLAR FRACTION OF THE LEAF OF PLUMBAGO ZEYLANICA (LINN.) PLUMBAGINACEAE.

The increasing challenge of antibiotic resistance has necessitated the search for alternative antibacterial agents from natural sources. Plumbago zeylanica L. (Plumbaginaceae), a medicinal plant widely used in African traditional medicine, is known for its antibacterial properties. This study aims to investigate the phytochemical composition and evaluate the antibacterial activity of the non-polar fraction of P. zeylanica leaf. N-hexane fraction was obtained from the hydroalcohol extract following isocratic elution with n-hexane. Phyto-constituents were determined by preliminary phytochemical screening and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Susceptibility test was achieved by Agar well diffusion protocol, while broth dilution method was used to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Phytochemical screening revealed the following: flavonoids, saponins, terpenoids, alkaloids, and phenolic compounds. GC-MS analysis afforded fifty-seven compounds with naphthalene, decahydro-2-methyl (4.02 %), benzene-1-methyl-3-propyl (4.37 %), naphthalene, decahydro-, trans (4.49%), ethyl, 9,12,15-octadecatrienoate (4.54%), benzene-1,4-diethyl- (4.72%), benzene-1,2,4,5-tetramethyl (4.75%), n-tetracosanol-1 (5.04%), hexadecanoic acid ethyl ester (5.28%) and benzene-1,2,4-trimethyl (6.00%) as the most noticeable. The antibacterial assessment demonstrated selective zones of inhibition against Escherichia coli (13 mm) and Bacillus cereus (17 mm). MIC and MBC against E. coli were 3.8 mg/mL and 15 mg/mL, while for B. cereus, they were 30 mg/mL each. The results indicate that P. zeylanica fraction contains bactericidal compounds particularly against E. coli and B. cereus. [ABSTRACT FROM AUTHOR]