Analysis of Phytochemicals and Functional Groups From Aqueous Extracts of Malawian <i>Vernonia amygdalina</i> Del. for Potential Applications

Vernonia amygdalina Del., a plant recognised for its medicinal properties, is widely available in Malawi, but remains underutilised. The study aimed to analyse phytochemicals and their functional groups in the aqueous extracts of V. amygdalina Del. leaves. The functional groups of the compounds were determined using Fourier-transform infrared spectroscopy (FT-IR). Phenolic compounds were quantified using high-performance liquid chromatography-ultraviolet visible assay. Gas chromatography mass spectrometry was used to identify volatile phytoconstituents. The FT-IR spectrum revealed characteristic absorption bands corresponding to C═C, C═O, C═O, ─OH and ─NH active functional groups. The phenolic compounds identified included gallic acid, sinapic acid, vanillic acid, ferulic acid, rutin and quercetin, whose concentrations varied significantly (p < 0.05). Volatile compounds (21) were observed with dl-α-Tocopherol as a major compound, followed by β-sitosterol, ethyl iso-allocholate, 9,12,15-octadecatrienoic acid, 2,3-dihydroxypropyl ester, (Z,Z,Z)- and stigmasterol. The aqueous extracts of V. amygdalina Del. leaves contained phytochemicals with active functional groups that can act as reducing and capping agents, thereby demonstrating potential applications in green chemistry. Based on these findings, we recommend further studies using this extract to actually synthesise silver and zinc oxide nanoparticles and characterise them using spectroscopic techniques for use in promoting sustainable farming practices.