isolation and characterization of bioactive compounds from scotch thistle (onopordum acanthium l.) seeds

Background: scotch thistle (onopordum acanthium l.) is a medicinal food plant known for its phytochemical diversity. methods: in this study, methanolic and petroleum ether extracts of scotch thistle seeds were subjected to phytochemical analysis. as regards, methanol extract was fractionated via different chromatographic methods and structures of the isolated pure compounds were elucidated with relative nuclear magnetic resonance spectra. additionally, scotch thistle oil was analyzed via gas chromatography-mass spectrometry (gc-ms). besides, the invitro 2,2-diphenyl-1-picrylhydrazyl (dpph) antioxidant property of o. acanthium extract was evaluated. results: structure elucidation of the isolated major compounds of the extract yielded to seven major metabolites, revealing the presence of five lignan and two serotonin derivatives, including arctiin, arctigenin, and matairesinol, with six compounds being newly reported from o. acanthium. furthermore, gc-ms analysis identified eight fatty acids in the seed oil, with linoleic acid (63.4%) and 13-octadecenoic acid (28.2%) being the predominant components. the antioxidant potential of scotch thistle exhibited strong antioxidant activity, as reflected by rc50 values ranging from 2.1 to 501.9 µg/ml for various methanolic fractions of o. acanthium. conclusion: these findings highlighted the rich bioactive content of scotch thistle, underscoring its significance in medicinal and ecological contexts.