Phenolic compounds characterization by LC-DAD- ESI/MSn and bioactive properties of Thymus algeriensis Boiss. & Reut. and Ephedra alata Decne

Scientific research has been focused on finding natural occurring molecules from plant origin. Herein, infusion, decoction and hydroethanolic extracts of Thymus algeriensis Boiss. & Reut. and Ephedra alata Decne. from Algeria were phytochemically characterized by LC-DAD-ESI-MSn, and evaluated regarding bioactive properties (antioxidant and antibacterial). Flavonol and flavone glycoside derivatives and phenolic acids, specially rosmarinic acid and kaempferol-O-glucuronide were the major compounds in T. algeriensis extracts. Otherwise, E. alata presented isoflavones and flavonol derivatives as main compounds, being hydroxypuerarin isomer 1 the major molecule. Aqueous extracts had significantly higher antioxidant activity, being this activity correlated with the amount of phenolic compounds. Antimicrobial activity of the extracts was tested against multi-resistant bacteria strains from clinical isolates. The obtained MIC values indicate that the hydroethanolic extracts revealed the highest effect, especially the one of T. algeriensis against Gram-positive bacteria. Hence, these plant extracts could be used in the development of bioactive ingredients.