[Study on enzyme-solvent extraction process of flavonoids from leaves of Ginkgo biloba].

OBJECTIVE: To study the optimum enzyme-solvent extraction conditions of flavonoids from leaves of Ginkgo biloba. METHODS: To optimize the process by single factor experiments and orthogonal test according to the yield of flavonoids. RESULTS: The optimum extraction conditions were established as follows: pH 5.7, the concentration of enzyme 0.4 mg/mL, enzymatic hydrolysis temperature 45 degrees C, enzymatic hydrolysis time 2 h, the rate of liquid to material 20:1, extraction temperature 70 degrees C, extraction time 2 h, the concentration of ethanol 70%, the average yield of flavonoids from leaves of Ginkgo biloba was 3.62%. CONCLUSION: The method is simple and can increase material utility effectively.