The bioactive components of Coreopsis tinctoria (Asteraceae) capitula: Antioxidant activity in vitro and profile in rat plasma

•Three compounds were identified from the capitula of C. tinctoria for the first time.•Eleven compounds possessed antioxidant activities based on DPPH and CAA assay.•The content of the eleven active phenolic compounds was determined by LC-MS/MS.•Phenolic profile of C. tinctoria capitula in rat plasma was depicted.•C. tinctoria capitula might be developed as antioxidant sources.