Isolation, Characterization and Identification of a Flavonoid from Capsicum annuum Fruits and its Antibacterial Activities Against Clinical Isolates

Abstract

Plants have been used in traditional medicine for thousands of years, and their therapeutic properties have been studied extensively since synthetic medications are not always an option. Antimicrobial resistance and the obvious negative effects of synthetic medications have sparked a renewed interest in the hunt for novel agents to treat both new and old infectious illnesses. This study aimed to contribute to this effort by extracting and characterising potential therapeutic compounds from Capsicum annuum fruit and then testing those compounds' efficacy against various clinical disease-causing bacteria. The plant material under study was reduced to a powder and then extracted using a soxhlet apparatus using n- hexane and ethyl acetate, respectively. The hexane extract underwent phytochemical analysis, the results of which indicated the presence of alkaloids, flavonoids, steroids, phenols, tannins, and saponins. Using GC-FID, we were able to determine the concentrations of these phytochemicals; the results indicated a cyanogenic glycoside (9.3843 ppm) to have the highest concentration and a cardiac glycoside (1.6804 ppm) to have the lowest. The results of the proximate analysis showed that the concentration of carbohydrate was the greatest (at 40.636%), while the concentration of ash was the lowest (at 2.214%). Methanol was added little by little while the extracts were being separated on a silica gel column in ethyl acetate. The calculated fractions were analysed. TLC, UV, and IR spectroscopy were used to evaluate the resulting fractions, and from there, 50 fractions were aggregated into 10 combined fractions for NMR (1D and 2D) analysis to determine the structures of their components. Hesperetin, a kind of flavonoid, was identified as JLS-3's chemical makeup. High susceptibility of bacteria to the isolated chemical in the antimicrobial assay suggests the isolated natural flavonoid may be useful as a pretreatment for illnesses caused by these pa