Chemical Contents Profile of Essential Oil from Calamansi (Citrus microcarpa Bunge) Peels and Leaves and Its Antibacterial Activities

Citrus is a plant that has many health benefits and has been widely reported for its pharmacological effects.One of the citrus that has been reported to have antibacterial activity is calamansi (Citrus microcarpa Bunge).This study aims to determine the chemical content profile of the essential oil of fruit peels and leaves of calamansi.The essential oil was isolated by distillation of water and analyzed for chemical compound content by GC-MS.The methods used to determine the antibacterial activity of essential oils are diffusion and dilution methods.GC-MS results show that the main components of essential oil in the peels of the calamansi are D-limonene (29.52%), (R)-(+)-citronellal (13.76%), 3-isopropenyl-5,5-dimethyl-cyclopentene (8.88%), γ-terpinene (7.30%), citronellol (6.90%), and α-terpineol (4.61%) while the calamansi leaves consist of citronellal (25.74%), citronellol (12.94%), 3-carene (8.43), and β-phellandrene (4.89%).The essential oil of the fruit peels and leaves of calamansi showed antibacterial activity against MRSA, S. aureus, S. mutans, P. aeruginosa and E. coli bacteria.In the antibacterial activity test, the diffusion method showed that the essential oil of the fruit peels had moderate to strong inhibitory power, while the leaves of calamansi had very strong inhibitory power.In the dilution antibacterial activity test, it showed that the smallest MIC in the essential oil of fruit peels was a concentration of 0.39%, while the essential oil for leaves was 0.2%.The diffusion and dilution method of antibacterial activity test showed that the essential oil of the leaves was more potent than the peels of the calamansi.