Asian Journal of Biochemistry, Genetics and Molecular Biology

The present study investigates the isolation and characterisation of lupeol from Ficus racemosa and rutin from Annona squamosa to evaluate their synergistic antioxidant and antimicrobial effects. The study includes the phytochemical profiles, antimicrobial activity, and antioxidant potential of Ficus racemosa and Annona squamosa extracts. Phytochemical screening of methanolic and ethanolic extracts revealed key secondary metabolites, including flavonoids, steroids, saponins, glycosides, tannins, and carbohydrates, although variations were observed between the two plant species. Methanolic extracts of Ficus racemosa were rich in phenolics, flavonoids, quinones, and saponins, whereas ethanolic extracts of Annona squamosa predominantly contained flavonoids, alkaloids, and glycosides. Chromatographic analysis using thin-layer chromatography confirmed the presence of bioactive compounds such as lupeol and rutin, with Rf values consistent with those of the standard compounds. Structural characterisation by UV-Vis and FTIR spectroscopy supported the identity of the isolated compounds by revealing characteristic functional groups. Further confirmation and purity assessment using HPLC demonstrated distinct retention times for lupeol (4.32 min) and rutin (~5.497 min), indicating successful isolation. Antimicrobial activity, evaluated using the agar well diffusion method, showed that both plant extracts inhibited Gram-positive and Gram-negative bacteria. The combined extract (1:1) showed greater antibacterial activity at higher concentrations, particularly against Staphylococcus aureus and Escherichia coli, as indicated by increasing zones of inhibition. Gram-positive bacteria were more susceptible under the conditions tested. Antioxidant activity assessed using the DPPH assay showed strong free-radical-scavenging activity of the combined extract, with an IC₅₀ value of 0.28 mg/mL, compared with 0.26 mg/mL for ascorbic acid. Overall, the findings indicate that Ficus racemosa and Annona squamosa extracts possess antioxidant and antimicrobial activities under the experimental conditions used.