Comparison of Chemical and Antimicrobial Studies of Egyptian Mandarin Leaves and Green Branches Volatile Oil

Aims: In the present study we compared the chemical composition and the antimicrobial activity of the essential oils isolated from green branches and leaves of mandarin.

Study Design: Extraction of essential oils from mandarin green branches and leaves by hydrodistillation

Place and Duration of Study: leaves and green branches were collected from Benha City, Qualyobia, Egypt in December 2012.

Methodology: The essential oils (EOs) isolated from mandarin (Citrus reticulata) were analyzed by GC and GC/MS. The antimicrobial activity was assessed using agar well diffusion method.

Results: Sixteen compounds were identified from the oil of branches which represented about 92% of the total detected constituents. The major components of the oil were dimethyl anthranilate (34.7%), γ-terpinene (33.6%) and limonene (11.2%). Alpha pinene and sabinene were present in considerable amounts (both at 2.8%). Other components were present in amounts less than 2%. From the heavier of layer mandarin leaves oil, thirteen compounds accounting for 95.4% of the oil were identified. Dimethyl anthranilate (65.3%) was the major component, followed by γ-terpinene (19.8%) and limonene (4.5%).

On the other hand, fourteen compounds (94.7%) were identified from the lighter layer of mandarin leaves oil including dimethyl anthranilate (60.6%), γ-terpinene (22.8%) and limonene (5.3%).

The antimicrobial activities of the oils were assessed. The antifungal activity was studied against Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans. The antibacterial activities were measured against Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis as gram (+) bacteria; and Klebsiella pneumonia, Escherichia coli, Salmonella typhimurium as gram (-) bacteria.

Conclusion: The heavier layer of mandarin leaves oil was the most effective layer against all tested microorganisms, followed by the branches oil and finally the lighter layer of leaves oils.