Integrated Phytochemical Characterisation and LC-MS/MS Profiling of Portulaca oleracea with Antioxidant and Antimicrobial Activity Assessment

Abstract

The present study evaluates the phytochemical profile, antioxidant activity and antimicrobial potential of the ethanolic extract of Portulaca oleracea, revealing a high abundance of flavonoids, phenolic acids, tannins and cardiac glycosides, with weak terpenoid presence and absence of alkaloids, confirming ethanol as an effective solvent for polyphenol extraction. Quantitative analysis demonstrated significantly higher total phenolic and flavonoid contents compared to previously reported studies, reflecting the superior polyphenolic richness of the extract. LC-MS/MS profiling enabled the annotation of diverse bioactive constituents, including phenolic acids, flavonoids, flavonoid glycosides and high-molecular-weight polyphenols such as procyanidin oligomers and tannins, with consistent mzCloud and ChemSpider FISh scores supporting confident compound identification. The extract exhibited strong antioxidant activity, particularly in the DPPH free radical scavenging assay, with lower IC₅₀ values than earlier reports, while ABTS⁺ assay results indicated comparable but assay-dependent efficacy. Furthermore, the extract showed moderate broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria, as evidenced by measurable zones of inhibition and minimum inhibitory concentrations. One-way ANOVA followed by Tukey’s HSD post hoc analysis revealed no significant variation among the samples (p > 0.05), indicating a high degree of consistency and supporting the standardisation of P. oleracea extracts.