Phytochemical Profiling and Characterization of the Ethanol Leaf Extract of Buchholzia coriacea (Wonderful Kola) Using GC–MS Analysis

Background: Buchholzia coriacea is a medicinal plant widely used in West African traditional medicine for treating ailments such as diabetes, malaria, hypertension, and gastrointestinal disorders. Its leaves contain bioactive phytochemicals with strong antioxidant and neuroprotective properties, making it a promising natural alternative to synthetic drugs. Aim: This study aimed to evaluate the phytochemical composition, anti-nutrient content, antioxidant activity, Fourier transform infrared (FTIR) characteristics, and GC–MS profile of ethanol leaf extracts from fresh and freeze-dried Buchholzia coriacea. Study Design: An experimental laboratory-based study involving qualitative and quantitative phytochemical analyses, spectroscopic characterization, and chromatographic profiling. Place and Duration of the Study: The study was conducted in a laboratory setting of the Federal University of Technology, Akure and Bamidele Olumilua University of Education Science and Technology Ikere Ekiti, over a defined experimental period. Methodology: Ethanol extracts were prepared from both fresh leaf extract (FLE) and dried leaf extract (DLE) of Buchholzia coriacea. Standard procedures were employed to determine phytochemical constituents (qualitative and quantitative) and anti-nutrient levels. Antioxidant activity was assessed using DPPH radical scavenging assay. Functional groups were identified using FTIR spectroscopy, while GC–MS analysis was used to characterize the chemical constituents of the extracts. Results: Phytochemical screening confirmed the presence of tannins, saponins, steroids, flavonoids, alkaloids, terpenoids, and anthraquinones in both extracts. Quantitative analysis revealed significantly higher concentrations in DLE compared to FLE, with alkaloids (7.92 ± 0.17 mg/g), saponins (5.28 ± 0.10 mg/g), and flavonoids (4.61 ± 0.15 mg/g) being predominant. GC–MS analysis identified 13 compounds in FLE, mainly caffeine (8.78%), n-hexadecanoic acid (7.68%), and octadecane (6.59%), while 19 compounds were detected in DLE, dominated by n-hexadecanoic acid (28.82%), 1,2-benzenedicarboxylic acid mono(2-ethylhexyl) ester (28.40%), and lupeol (7.17%). The extracts exhibited strong antioxidant activity, with DPPH scavenging values of 84.45% (FLE) and 85.81% (DLE) at 30 mg/mL. FTIR analysis confirmed the presence of hydroxyl, carbonyl, aromatic, ether, and amine functional groups. Conclusion: The findings validate the ethnomedicinal relevance of Buchholzia coriacea and highlight its potential as a rich source of bioactive compounds, supporting its prospective application in pharmaceutical development.