Abstract:  The extract of Ginkgo biloba L leaves. was hydrolyzed by hydrochloric acid and β-Glycosidase respectively to prepare the flavone aglycone. The orthogonal design test was adopted to find out the optimal processing conditions of both methods. Results showed that the optimal acidic hydrolysis conditions are as follows: 80% methanol as medium in which hydrochloric acid concentration 4 mol/L, ratio of GBE weight to solvent volume (mg/ml) 2:1, and hydrolyzing for 4 h at 70 ℃; The optimal enzymatic hydrolysis conditions are as follows: pH 5.0, enzyme concentration 5×10-3 mg/ml, and hydrolyzing for 6 h at 40 ℃. Through comparing their HPLC spectra of the hydrolysates, it was known that there are only flavonoid aglycones in the acidic hydrolysate, while in the enzymatic hydrolysate there are still many other functional ingre-dients such as ginkgolides. So the method of enzymatic hydrolysis is helpful to retain the comprehensive bio-function of the extract.

Key words: extract of Ginkgo biloba leaves； flavonoid aglycone； &beta, -Glycosidase； hydrolysis