Chemical Characterization and Phytochemical Profiling of Ethanol Leaf Extracts of Chromolaena odorata, Anacardium occidentale, and Phyllanthus amarus Harvested in Calabar, Nigeria

Abstract

Medicinal plants continue to constitute an invaluable source of natural bioactive chemicals with diverse Pharmaceutical Potentials. This study evaluated the chemical composition and phytochemical profile of ethanol leaf extracts of Chromolaena odorata, Anacardium occidentale, and Phyllanthus amarus harvested in Calabar, Nigeria. The aim was to characterize their secondary metabolites and identify key bioactive constituents responsible for their pharmacological activities. Qualitative phytochemical screening was carried out to detect major compound classes, while Gas Chromatography–Mass Spectrometry analysis was utilised to determine their chemical constituents. The results revealed that all three extracts contained phenols, flavonoids, tannins, steroids, alkaloids, terpenoids, and cardiac glycosides in varying proportions. GC–MS profiling identified 33 compounds in A. occidentale, 28 in C. odorata, and 30 in P. amarus. Dominant components included ethyl palmitate, β-farnesene, 2,4-di-tert-butylphenol, and undecane derivatives, which are associated with antioxidant, antimicrobial, and anti-inflammatory activities. Comparative evaluation with previous findings confirmed the chemical consistency of these plants, though environmental factors influenced compound abundance. These findings demonstrate that the studied species are chemically rich in pharmacologically relevant compounds and validate their traditional applications in managing oxidative stress and microbial infections. The study provides a basis for future isolation and bioassay-guided investigations toward developing standardized phyto-therapeutic formulations.