Optimization of ultrasound‐assisted extraction parameters for improving content of acteoside, luteolin‐7‐ O ‐glucoside, and total polyphenols in extracts of Plantago lanceolata aerial parts

Abstract

This study was designed in order to determine optimal parameters for ultrasound-assisted extraction (UAE) of polyphenols from plantain herb using response surface methodology (RSM) as well as UV-visible spectrophotometric and reverse-phase high-performance liquid chromatographic (RP-HPLC) method. Solvent extraction was performed based on four factors-five levels central composite design (CCD). The influence of extraction time (X1: 5–65 min), ethanol concentration (X2: 10%–90%), solid to solvent ratio (X3: 1:10–1:50), and extraction temperature (X4: 20–80°C) on total polyphenols content (TPC) as well on content of dominant individual polyphenolic compounds (acteoside and luteolin-7-O-glucoside) was analyzed. The optimal extraction parameters were as follows: extraction time of 64 min, ethanol concentration of 45%, solid to solvent ratio of 1:49, and extraction temperature of 40°C. Under these optimal conditions, the experimental values for total phenolics and acteoside and luteolin-7-O-glucoside content in plantain herb extract were 42.15, 24.15, and 0.87 mg/g DW, respectively. Experimental validation of optimized parameters was performed and close agreement with predicted values suggested the effectiveness of the applied model and the achievement of RSM in optimizing the extraction parameters. Practical applications In this study, we have analyzed optimal conditions for ultrasound-assisted extraction of polyphenols from ribwort plantain aerial part using response surface methodology. These developed conditions will help other researchers and industrialists to develop functional food products with a high range of phytochemical potential.