Optimization of integrated extraction-adsorption process for the extraction and purification of total flavonoids from Scutellariae barbatae herba

In the present study, integrated extraction-adsorption process was developed and applied to extract and purify total flavonoids from Scutellariae barbatae herba. Screening of macroporous resins, single factor experiments, an experimental design based on Box-Behnken design (BBD) and purification conditions study were carried out to optimize the integrated process. DM130 resin was chosen as adsorbent and the optimal extraction-adsorption conditions were determined as pH of extraction solvent 2, time 9 h, liquid/solid ratio 20:1 mL/g and flow rate 7 BV/h. 70% (5 BV) ethanol aqueous solution was selected as elution solvent. Through this procedure, the total flavonoids of Scutellariae barbatae herba can be totally extracted using water as extraction solvent rather than high concentration ethanol was used in traditional extraction method. Moreover, the integrated process can simplify operation, reduce energy consumption, and prevent the degradation of bioactive substances, thus improve the quality of products. Compared to the conventional method, the recovery yield and purity of total flavonoids obtained from this procedure increased by 1.50 and 1.16 times respectively. The results showed that the integrated procedure can be efficient and eco-friendly, as well as appropriate for large-scale extraction and purification of total flavonoids from Scutellariae barbatae herba.