Optimization of phenolic and flavonoid content and antioxidants capacity of pressurized liquid extraction from Dracocephalum kotschyi via circumscribed central composite

The extract was separated from aerial parts of Dracocephalum kotschyi using percolation and pressurized liquid extraction (PLE). A circumscribed central composite (CCC) was used to optimize the effective extraction variables. For achieving maximum extraction yield via PLE the temperature, pressure, static time, dynamic time, and the solvent flow rate were adjusted 74 degrees C,34 bar, 11.33 min, 17.45 min, and 0.7 mL/min, respectively. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (mu g/mL) via high performance liquid chromatography was evaluated and the highest antioxidant activity was observed from the PLE extract. The results indicated the aerial parts of this plant are a potential source of natural antioxidants and flavonoids. The PLE method is quicker and it has more extraction yield, total phenolic, and total flavonoids than percolation. (C) 2015 Elsevier B.V. All rights reserved.