Metabolite profiling and a molecular networking approach for the quality control of elephant's root, Entada...

Entada elephantina (Burch.) S.A. O'Donnell & G.P. Lewis (formerly Elephantorrhiza elephantina (Burch.) Skeels), a member of the Fabaceae, is an ethnomedicinal plant widely used in South Africa. Despite studies supporting its traditional applications, comprehensive phytochemical characterisation remains limited. In this study, chemical profiling and marker quantification were performed on methanolic root extracts of E. elephantina (n = 50) collected from the Northern Cape Province, South Africa. High-performance thin-layer chromatography coupled to mass spectrometry (HPTLC-MS) and LC-MS analyses confirmed the presence of catechin, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), quercetin 3'-glucoside, and gallic acid across all samples. Ultra-high performance liquid chromatography-diode array detector-quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QToF-MS) enabled the tentative identification of 93 metabolites, predominantly flavonoids and their acylated derivatives, alongside minor phenolic and organic acids. Detected flavonoids included (epi)catechin aglycone derivatives, galloylated flavonoids such as taxifolin galloylated hexoside, and dimeric and trimeric ECG derivatives. Quantification using a validated UPLC-PDA method demonstrated notable variation in quercetin 3'-glucoside (1.23-2.54 mg/kg), catechin (0.42-0.88 mg/kg), ECG (0.39-0.74 mg/kg), kaempferol (0.008-0.018 mg/kg), and EGCG (0.004-0.014 mg/kg). Molecular networking revealed two principal structural subclusters, reflecting spectral similarity and shared fragmentation patterns within flavonoid families. This comprehensive chromatography-based approach establishes a phytochemical reference framework to support quality control, standardisation, and potential commercial development of this medicinal species.