Algerian Sonchus oleraceus L.: a comparison of different extraction solvent on phytochemical composition, antioxidant properties and anti-cholinesterase activity

Aerial parts of Sonchus oleraceus L. were studied for the antioxidant and anti-cholinesterase activities in different solvent and fractions. Extracts/fractions were analysed for total phenolic, flavonoid and flavonol contents. The chemical constituents of the most active extracts/fractions were analysed using LC–MS/QTOF in the positive ion mode. Ethyl acetate and butanolic fractions exhibited the highest antioxidant activity in DPPH, galvinoxyl and phenanthroline assays due to high contents of phenolics, flavonoids and flavonols. Whereby total alkaloid extract had the highest scavenging activity in ABTS•+ assay. Besides, methanolic extract was noted for the highest inhibitory effect against acetylcholinesterase. Total 24 compounds were identified by LC–MS/QTOF which were phenolic acids, sesquiterpene lactones and phenylpropanoid derivatives. As conclusion, the study revealed that the aerial parts of S. oleraceus are potential sources of natural antioxidant and anti-cholinesterase compounds.