Chemical Composition and Antimicrobial Activity of Essential Oil from Aerial Part (Leaves and Fruit) of Eucalyptus gomphocephala DC

Abstract

The objective of this study was to investigate the species identification, chemical composition and the antimicrobial activity of tuart (Eucalyptus gomphocephala DC) fruits and leaves. The essential oil content was 0.34 % and 0.23 % in the fruits and leaves, respectively. The main essential oil constituents of tuart fruits were 1,8-cineole (46.69 %), p-cymene (8.99 %), baeckeol (8.57 %), α-pinene (5.21 %), and globulol (4.25 %). The main essential oil constituents of tuart leaves were 1,8-cineole (24.25 %), p-cymene (20.70 %), α-pinene (14.15%), β-pinene (8.17 %), γ-terpinene (6.90 %), methyleugenol (6.78 %), α-terpineol (4.75 %), and limonene (3.80 %). The antimicrobial activity of essential oil was examined against Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis, Kocuria rhizophila; Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, Salmonella abony; yeast Saccharomyces cerevisiae, Candida albicans; and fungal strain Aspergillus brasiliensis according to the agar well diffusion method. The leaf essential oil showed higher antimicrobial activity against almost all strains of the microorganisms tested, with Salmonela abony being the most sensitive microorganism by having zone of inhibition 28.6 mm, followed by Escherichia coli (27.9 mm), Bacillus subtilis (26.2 mm) and Pseudomonas aeruginosa (25.8 mm). The tuart fruit essential oil had lower activity against tested microorganisms. Aspergillus brasiliensi was the most resistant microorganism to the inhibitory activity of the fruit and leaf essential oil in this study. Thus, tuart fruits and leaves essential oil have the potential to be used as a new source for the pharmaceutical and cosmetic products.