Supercritical fluid extraction of flavonoids from Scutellariae Radix

An optimal condition of supercritical fluid extraction (SFE) for flavonoids of Scutellaria baicalensis was developed. In this study, various temperatu res, pressures and modifiers were studied. The conventional extraction meth ods were conducted in parallel for comparison. The crude extracts were qual itatively compared by TLC and GC-MS, and the contents of flavonoids were de termined by HPLC. The amounts of baicalin, baicalein and wogonin in the Scu tellariae Radix obtained by supercritical fluid extraction and a convention al sonic shaking method were 137.6 mg/g, 8.6 mg/g and 2.2 mg/g, 113.5 mg/g, 5.7 mg/g and 2.3 mg/g, respectively. Application of SFE for extraction of the flavonoids from Scutellariae Radix was preferable. The optimal conditio ns of SFE was as follows: supercritical carbon dioxide-MeOH-water (20:2.1:0 .9), 50 degrees C and 200 bar. (C) 1999 Elsevier Science B.V. All rights re served.