Simultaneous quantification and validation of caffeoylquinic acids and flavonoids in Hemistepta lyrata and peroxynitrite-scavenging activity

► Thirteen phenolic substances were identified and quantified in Hemistepta lyrata. ► Those thirteen substances include phenolic, flavones, and flavonol glycosides. ► Caffeic acid derivatives (CADs) showed stronger activity of peroxynitrite-scavenging. ► The 70% MeOH extract showed a higher quantity of caffeic acid derivatives. ► CADs are the main contributors to the peroxynitrite-scavenging activity of H. lyrata.