Tentative Phytochemical Profiling of Combretum paniculatum Vent. (Combretaceae) Leaf Extract by FTIR and LC-ESI-Q-TOF-MS/MS: Putative Identification of Eight Bioactive Metabolites and Their Pharmacological Relevance

Abstract

Background: The phytochemical composition of Combretum paniculatum Vent. leaves remains insufficiently documented, particularly regarding functional-group characteristics and tentative metabolite assignments. Aim: This study aimed to characterise a 70% ethanolic leaf extract using Fourier-transform infrared (FTIR) spectroscopy and liquid chromatography–electrospray ionisation–quadrupole time-of-flight tandem mass spectrometry (LC-ESI-Q-TOF-MS/MS). Methods: Leaves collected in the Toumodi Department, Côte d’Ivoire, were authenticated and macerated in 70% ethanol. The authenticated plant material carried herbarium number UCJ018534. Maceration was conducted for three hours before the extract was concentrated. The extract was examined using a Perkin Elmer Spectrum BX FTIR spectrometer and an Agilent 1260 HPLC system coupled to a 6530 Q-TOF mass spectrometer operating in positive ionisation mode. Assignments were based on accurate mass, proposed molecular formulae, fragmentation patterns, and comparisons with published information and databases, without authentic reference standards. Results: FTIR bands at 3287.83, 2926.38 and 1593.11 cm⁻¹, together with bands at 1357.96, 1193.33, 1107.91 and 1041.35 cm⁻¹, indicated functional groups compatible with hydroxylated, aliphatic, aromatic and oxygenated constituents. Eight metabolites were putatively annotated: quisqualic acid, gallocatechin, kaempferol, rhamnocitrin, oleanolic acid, 1-tetracosanol, maslinic acid and O-galloyl-6-O-(4-hydroxy-3,5-dimethoxy)benzoyl-β-D-glucose. Conclusion: The findings provide a preliminary phytochemical profile of the leaves. Compound isolation, structural confirmation, quantification and biological assays are required before their pharmacological significance can be established.