ABSTRACT
OBJECTIVE： To establish the method for content determination of total flavonoids from Combretum alfrdii， and to optimize the extraction technology of total flavonoids from C. alfrdii. METHODS： Using aluminium trichloride as， chromogenic agent， UV spectrum was adopted to determine the content of total flavonoids from C. alfrdii. Based on single factor test， ethanol volume fraction， material-liquid ratio， extraction time， extraction temperature and times were selected as investigation factors， and the content of total flavonoids was selected as response value， Plackett-Burman design was used to screen the factors that had significant influence on the content of total flavonoidsfrom C. alfrdii. Then steepest climbing test was adopted to confirm the optimum valuing range； the extraction technology of total flavonoids was optimized by Box-Behnken response methodology. RESULTS： The linear range of total flavonoids were 0.012-0.036 mg/mL （r＝0.999 9）； RSDs of precision， stability and repeatability tests were less than 3％； the recovery ranged from 92.98％ to 99.86％ （RSD＝2.71％， n＝6）. The optimal extraction technology included that 60％ ethanol， material-liquid ratio of 1 ∶ 34 （g/mL）， extracting for 3 times， lasting for 60 min， extraction temperature of 80 ℃. Under this technology， average content of total flavonoids from C. alfrdii was 2.71％ （RSD＝1.69％， n＝6）， and the relative error was 2.65％ compared with predicted value of the model （2.64％）. CONCLUSIONS： Established method is stable and reproducible， and can be used for content determination of total flavonoids from C. alfrdii. The optimized extraction method is stable and feasible.