Phytochemical and antimicrobial analyses of Plectranthus amboinicus leaf extracts

The present study is to evaluate the phytochemical constituents and antimicrobial activity of Plectranthus amboinicus leaf extract using petroleum ether, methanol and water as solvents. The antimicrobial activity of P. amboinicus leaf extracts were examined against the selected bacterial and fungal isolates namely Escherichia coli, Staphylococcus aureus and Aspergillus niger, Candida albicans using agar well diffusion method. FT-IR analysis was performed to identify the presence of functional groups in the methanol extract. The results of the study revealed the presence of distinctive active secondary metabolites in the tested leaf extract. The results revealed that the methanol extract exhibited maximum antimicrobial activity against the tested bacterial and fungal isolates when compared with aqueous and petroleum ether extracts. The FT-IR analysis reveals the presence of functional groups such as hydroxyl, amines, alkynes, ketones and carboxylic acid in the methanolic extract of P. amboinicus. Thus, P. amboinicus leaves are effective against the selected microbes and recommends that the plant derived phytochemicals are comparatively safer than synthetic alternative, thereby contributing insightful remedial benefits for the treatment of diseases.