Abstract: Hexane, ethyl acetate and methanolic extracts of dried powdered leaves of Eucalyptus globulus were screened for basic secondary metabolites and antibacterial activity against C. pyogenes, S. aureus, S. faecallis, B. stearothermophilus, S. epidermidis, B. cereus, B. polymyxa, K. pneumonia, P. aeruginosa, B. anthacis, B. subtilis, E. coli, P. fluorescens and C. sporogenes. Phytochemical investigation of crude extracts of Eucalyptus globulus (leaf) revealed the presence of tannins, phlobatannins, saponins, flavonoids, steroids, terpenoids, cardiac glycosides and reducing sugar in the plant. The antimicrobial sensitivity of the extracts against four species of Gram-ve and ten Gram+ve bacterial stain for Eucalyptus globulus (leaf) revealed very high antimicrobial activity. The extracts of hexane, ethylacetate and methamol of Eucalyptus globulus (leaf) were all very active on almost all the bacterial strains. The Infra Red (IR) spectra revealed the presence of different functional groups ranging from OH (3406-3338.6 cm 1) stretching, C-H (2926.6 cm 1, 864.1 cm 1) stretching alkyl, methyl C = 0, (2162.1 cm ) anhydrides, C = C (1697.6 cm 1) aromatic ring sretching, C-0 (1310.6-1059 cm 1) alcohol, ethers, esters, carboxalic acid bending.
P.A. Egwaikhide , S.O. Okeniyi , E.E Akporhonor and S.O. Emua , 2008. Studies on Bioactive Metabolites Constituents and Antimicrobial Evaluation of Leaf Extracts of Eucalyptus Globulus . Agricultural Journal, 3: 42-45.