Phenolic and antioxidant assessment of the flowers, stems, leaves, and fruits of Rosa pimpinellifolia and Rosa canina at different growth time

Natural plants are abundant in their native habitats and are traditionally used to treat a variety of health conditions. The Rosa genus stands out as an important species rich in bioactive compounds. This study, conducted in Türkiye, aimed to analyse the antioxidant and phenolic profiles of methanolic extracts obtained from different parts of Rosa canina (R.c.) and Rosa pimpinelifolia (R.p.) collected in 2021 and 2022. The antioxidant activity values of R.c. collected in 2021 and 2022 were found to be between 5 102.31–46 396.36 mmol Fe(II)/100 g in ferric reducing antioxidant power (FRAP), 141.92–377.54 mg ascorbic acid equivalents (AA)/kg in total antioxidant capacity (TAC), 2.18–24.68 µg/g in 2,2-diphenyl-1-picrylhydrazyl [DPPH (EC50)] and 34.31–75.77% in DPPH (% inhibition). Antioxidant activity of R.p. collected in 2021 and 2022 ranged from 17 258.44–71 903.20 mmol Fe(II)/100 g, 271.69–479.19 mg AA/kg, 1.02–8.32 µg/g and 50.98–85.57% for FRAP, TAC, DPPH (EC50) and DPPH (% inhibition), respectively. The R.p. extracts generally exhibited higher antioxidant activity than those of R.c. Considering the total identified phenolic compounds achieved from different plant parts of rosehip for both years, the highest values of total phenolic compounds were determined in R.c. leaves (222.08 mg/100 g) in 2021, and R.p. leaves (5 465.95 mg/100 g) in 2021.