Phytochemical analysis and antibacterial activity of acetone extract of Terminalia catappa Linn. leaves

Purpose: Traditional medicine has used the leaves of Terminalia catappa for various health benefits, with established antibacterial, antidiabetic, anti-inflammatory, antioxidant, antiviral, and hepatoprotective characteristics. This study aims to perform a phytochemical analysis and antibacterial assay of the acetone extract from T. catappa leaves. Methods: The dried leaves were subjected to extraction using 50 % acetone, followed by preliminary phytochemical screening, Gas chromatography-mass spectroscopy (GC-MS) analysis, and antibacterial testing of the extract. Results: Preliminary phytochemical screening identified the presence of carbohydrates, flavonoids, saponins, alkaloids, glycosides, tannins, phenols, terpenoids, and steroids/triterpenoids. GC-MS analysis showed the presence of epiglobulol and thirteen additional phytochemicals, which have been reported to possess antibacterial activity or potential, with epiglobulol exhibiting the highest concentration among all the identified phytochemicals. The diameters of the inhibition zones ranged from 0 to 15 mm for Staphylococcus aureus, 0 to 12 mm for Streptococcus pneumonia, 0 to 12 mm for Escherichia coli, and 0 to 8 mm for Pseudomonas spp, with greater extract concentrations leading to larger inhibition zones—though these were smaller than the inhibition zone diameters observed for gentamicin, which varied between 24.5 and 27 mm across the four tested organisms. Conclusion: The acetone extract of T. catappa leaves underwent phytochemical analysis, revealing numerous constituents known to exhibit antibacterial properties.