Comprehensive Profiling of Secondary Metabolites and Bio-Activity of Garcinia Kola (Heckel) Leaf
Nusirat Adenrinsola, Babatunde Zakari, and Akeem Oladapo Adebisi*
ABSTRACT
Garcinia kola is a West African medicinal plant traditionally used to manage infections and inflammation. While its seeds have been extensively studied, the leaves remain underexplored despite their potential as sources of antimicrobial agents. This study aims to investigate the phytochemical composition, functional groups, and antimicrobial activity of Garcinia kola leaf extracts using chemical and spectroscopic methods. Qualitative phytochemical screening, Fourier-transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS), and antimicrobial assays were performed on leaf extracts obtained via cold maceration using ethanol, methanol, aqueous, and n-hexane solvents. Antimicrobial activity was evaluated using the agar well diffusion method and Poison Plate Method against bacterial and fungal clinical isolates. Phytochemical screening revealed tannins as the only secondary metabolite consistently present in all extracts. FTIR analysis indicated key functional groups such as alcohols, aromatic amines, and carbonyls, while GC-MS identified compounds including phytol, neophytadiene, squalene, linoleic acid, and α-tocopherol. Antimicrobial assays showed selective activity only against Pseudomonas aeruginosa, with the n-hexane extract showing the highest inhibition zones (2.1–2.2 mm), while no effect was observed against other tested pathogens. Garcinia kola leaves possess narrow-spectrum antibacterial activity, particularly against Gram-negative bacteria. The presence of bioactive compounds suggests potential therapeutic applications. Further isolation, structural elucidation, and toxicity studies are required to validate these findings and advance the use of Garcinia kola leaf extracts in drug development
