Metabolite Profiling and Bioactivity Screening of Tylosema esculentum, Myrothamnus flabellifolius and Ozoroa paniculosa extracts using Ultra-Performance Liquid Chromatography–High-Resolution Mass Spectrometry (UPLC-HRMS)

Natural resources provide vital support to communities, and indigenous plants remain particularly important, as they are widely used for food, medicine, and cultural practices. In the quest to integrate these resources into modern applications, exploring their phytochemical composition is essential for both conservation and utilization. This study compared the phytochemical profiles, antioxidant capacity, and antimicrobial activity of Tylosema esculentum , Myrothamnus flabellifolius , and Ozoroa paniculosa using water, 80% methanol, and 50% acetone extracts. LC-MS profiling revealed M. flabellifolius as the most chemically diverse, with major flavonoids including quercetin 3-O-glucuronide and quercitrin. Acetone extracts of M. flabellifolius exhibited the highest DPPH scavenging activity (57.13%) and strongest antibacterial effects against E. coli , S. typhimurium , and S. aureus . The latter extracts displayed particularly demonstrated dose-dependent antimicrobial activity, with inhibition zones reaching up to 20.1 mm for E. coli and 16.9 mm for S. typhimurium . Solvent type significantly influenced the phytochemical content and bioactivity of the extracts, with 50% acetone generally outperforming water and 80% methanol. Overall, the indigenous plants of Botswana demonstrated considerable potential as sources of bioactive compounds for use as natural antimicrobial agents in food packaging and preservation. In particular, Myrothamnus flabellifolius exhibited the most diverse phytochemical profile and the strongest antimicrobial properties. These findings highlight the plant’s potential for development into natural antimicrobial products, warranting further investigation and application-focused research.