Hydroxychalcones as potent antioxidants: Structure-activity relationship analysis and mechanism considerations

► Mechanism and activity rely on the molecular structure and the reaction medium. ► Reversal of the activity order for hydroxychalcones were observed in acidified ethanol. ► SPLET and HAT mechanisms are responsible for GO-scavenging reaction of hydroxychalcones. ► Lipophilicity is important in anti-haemolysis experiment.