Evaluation of total phenolic and flavonoid contents and DPPH radical scavenging activity in Cotoneaster coriaceus Franch. extracts

This study aimed to evaluate the total phenolic and flavonoid contents, as well as the antioxidant capacities, of Cotoneaster coriaceus Franch. fruit and leaf extracts obtained using different solvents (acetone, ethyl acetate, and water). The highest levels of total phenolics (996.41 ± 8.30 µg GAE/mg extract) and flavonoids (403.53 ± 2.04 µg QE/mg extract) were detected in the leaf acetone extract. The leaf water and fruit acetone extracts also exhibited substantial phenolic and flavonoid contents. Among fruit extracts, acetone extract showed the highest phenolic (773.41 ± 12.67 µg GAE/mg extract) and flavonoid (135.28 ± 3.55 µg QE/mg extract) concentrations. The leaf ethyl acetate extract had a notably high flavonoid content (339.95 ± 3.97 µg QE/mg extract) despite its lower phenolic level. The antioxidant capacities of the extracts were assessed using the DPPH radical scavenging assay at various concentrations (12.5–400 µg/mL). All extracts exhibited a concentration-dependent increase in antioxidant activity (p 92% activity at 100 µg/mL. IC50 values further confirmed the antioxidant strength, with the lowest IC50 (10.55 µg/mL) observed in the leaf acetone extract, followed by the leaf water and fruit acetone extracts. Overall, these findings suggest that both plant part and solvent type significantly influence the extraction of bioactive compounds, with leaf acetone extracts offering the most promising antioxidant potential.