Ovidius University Annals of Chemistry, cilt.30, ss.44-47, 2019 (ESCI)
Rheum species are important medicinal herbs, often used in pharmacological research, due to the presence of
anthracene derivatives in the subterranean parts of the plant. In this study, we intended to assess its antioxidant capacity,
in correlation with the method of extraction. For this purpose, Rheum ribes extraction was realized with four solvents of
different polarities (50% methanol, 70% ethanol, 80% acetonitrile, and petroleum ether). We used different extraction
techniques, such as orbital shaker, ultrasonic stirrer, microwave, and Soxhlet extraction, and the total phenolic content of
the Rheum ribes extracts was determined by modified Folin–Ciocalteu method. The reducing power and radical
scavenging activity of the extracts were also evaluated. The results shown that the antioxidant activity of the extracts
depends on the extraction methods especially through the used solvent and decreases in the order: ethanol > methanol >
acetonitrile > petroleum ether.