In Vitro Antimicrobial Activity and GC-MS Analysis of Crude Aqueous Methanolic Extract Produced from Leaves of Eucalyptus species

Abstract

Objectives:To evaluate the antimicrobial activity of the aqueous methanolic extract was given by the leaves of Eucalyptus sp.growing in Thi-Qar Province, south of Iraq. Additionally, to detect the compounds within the extract by using the technique of gas chromatography-mass spectrometry (GC-MS). Methodology: The healthy leaves of Eucalyptus sp. were collected, washed with tap water then by distilled water, dried, and pulverized through using a small mill to make the dried leaves as a powder. The leaves powder was extracted by absolute petroleum ether then aqueous methanol (80%) for obtaining a sticky crude extract of the aqueous methanol filtrate. The crude extract was tested against some microbial pathogens as well as analysis of the extract using the technique of GC-MS and phytochemical tests. Results:The current study showed the antimicrobial activity of the crude aqueous methanolic extract obtained from Leaves ofEucalyptus sp. by which 40000 µg∕ml of the extract exhibited inhibition zones around Staphylococcus aureus, Streptococcus mutans, Escherichia coli, and Klebsiella sp. besides Candida albicans that the inhibition zones were measured to be 30, 27, 26, 30, and 38 mm respectively. The chemical tests appeared the crude extract containsalkaloids, glycosides, flavonoids, tannins, andsaponin glycosides. GC-MS analysis detected constituents of the extract are dimethylsulfoxoniumformylmethylide, diethyl phthalate, benzene,1,1'-(1,2cyclobutanediyl)bis-trans-,diisoctyladipate, and 2-methyl-7-phenylindole. Conclusion: The present study concluded that the leaves ofEucalyptussp. possess the bioactive products which are needed to be separatedas the pure compoundsby using techniques of chromatography in order to separately tested in vitro and in vivo, then application of spectrometry techniques for characterization of their chemical structure. Finally, these compounds can be used to treat diseasesas drugs in hospitals.