Research Article

Optimization of Ultrasonic Extraction of Phenolic Compounds from Epimedium brevicornum Maxim Using Response Surface Methodology and Evaluation of Its Antioxidant Activities In Vitro

Figure 2

HPLC chromatograms. (a) HPLC chromatograms of a standard solution ( gallic acid = 20 μg/mL, catechin = 20 μg/mL, (3) p-hydroxybenzoic acid = 20 μg/mL, (4) vanillic acid = 22 μg/mL, (5) caffeic acid = 20 μg/mL, (6) ferulaic acid = 19 μg/mL, (7) rutin = 20 μg/mL, (8) benzoic acid = 25 μg/mL, (9) quercetin = 10 μg/mL). (b) Typical HPLC chromatogram obtained by direct injection of 20 μL of extract of polyphenols from Epimedium brevicornum Maxim by optimized conditions (ethanol concentration 50%, extraction time 27.5 min, and ratio of aqueous ethanol to raw material 250 mL/g).