Abstract:
In this study, total phenolics and flavonoid compounds of methanolic extract concentrations of three medicinal plant, Asteraceae (Compositae) L. genus that are grown in Turkey and belong to the genus Achillea, were determined with the goal of measuring their antioxidant activities. Antioxidant capacity was measured by widely used iron reducing power, DPPH radical scavenging activity and metal chelating capacity. The antioxidant activities of the achillea extracts used in the study were compared with the standard antioxidants (BHA, BHT and α-tocopherol), which were frequently used as antioxidant food additives. According to the free radical scavenging activity antioxidant results, all the extracts exhibited higher DPPH radical scavenging activity than the standards used. The extract from A.boissieri showed remarkable 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (68.51% at 37.5 μg/mL) comparable with synthetic antioxidants. The ferric reducing antioxidant power was found to be moderate in methanolic extract of Achillea species, whereas the chelating capacity of the extracts were found to be lower as compared to the standards. In addition, total phenolic, flavonoid and flavonol content of all extracts were measured spectrophotometrically and the results were expressed as "gallic acid equivalent" or "quercetin equivalent". The total phenolic content was expressed as equivalents of gallic acid and the results were observed to range from 11.86 to 23.63 mg/g dry extract weight. The total flavonoid concentrations of Achillea extracts were expressed as quercetin equivalent. Flavonoid content ranged from 15.05 to 29.70 mg/g. Total flavonol concentrations of the extracts were determined to be between 5.92 and 7.20 mg/g in terms of quercetin equivalent. This study showed that Achillea L. species, which has been used for treatment in Anatolia for years, can be used as a potential natural antioxidant source. © 2021, Turkish Chemical Society. All rights reserved.