Optimisation of Phenolic Compound Extraction from Agrimonia eupatoria L. Using Response Surface Methodology for Enhanced Yield of Different Phenolics and Maximised Antioxidant Activity

Abstract

Agrimonia eupatoria L. is a traditionally used medicinal plant rich in tannin compounds with antioxidant, anti-inflammatory, and antimicrobial activities. This study aimed to optimise the extraction of individual phenolic acids, flavonoids, and tannins from A. eupatoria and maximise their antioxidant activity using response surface methodology (RSM). A central composite design was applied to evaluate the influence of acetone concentration, solvent ratio, and extraction time on the yield of total phenolics, total radical scavenging and reducing capacities, and individual compounds. Acetone concentration, solvent ratio, and extraction time were varied in a central composite design. The optimal conditions yielded high levels of agrimoniin (9.16 mg/g), total identified phenolics (33.61 mg/g), and strong antioxidant activity. These findings provide a scientific basis for standardising bioactive-rich extracts for nutraceutical and pharmaceutical applications.