Rhaponticum acaule (L.) DC. is a medicinal plant commonly used for the treatment of some illnesses such as gastrointestinal infections. In this work, we report the composition of different parts of this plant on phenolic compounds, their quantification, and antioxidant activity. The obtained results reported that methanolic extracts of the three parts studied revealed high phenolic contents. For flavonoid contents, the highest contents were reported in organic extracts of leaf part. In addition, results obtained from the study of the antioxidant activity showed that methanolic extract of root presented the highest activity, in DPPH• scavenging ability test with an IC50 of 0.31 ± 0.04 mg/mL and in FRAP test with an EC50 of 1.06 ± 0.02 mg/mL. The RP-HPLC-PDA analysis revealed the presence of five phenolic acids (sinapic, caffeic, chlorogenic, ferulic and syringic acids), one flavanone (naringenin), one flavonol (rutin) and vanillin.
Keywords: RP-HPLC-PDA; Rhaponticum acaule; antioxidant activity; asteraceae; medicinal plants; phenolic compounds.