Optimization of Ultrasonic Extraction of Total Flavonoids from Coreopsis Tinctoria Nutt. Using Response Surface Methodology

OBJECTIVE To optimize ultrasound extraction technology of total flavonoids from Coreopsis tinctoria Nutt.. METHODS With the content of total flavonoids as index, effects of ethanol concentration, solid-liquid ratio, ultrasonic time and temperature on extraction technology were investigated by single factor tests and Box-Behnken response surface methodology. RESULTS Optimum ultrasound extraction technology was as following: ultrasonic extracted 34 min with 40 times of 65% ethanol to the herb at 62 ℃. Under these conditions, the average extraction rate of flavonoids was 207.32 mg·g^-1(RSD=1.45%), which was very close to the predicted value of 208.81 mg·g^-1. CONCLUSION This optimized technology is stable and feasible to provide a basis for development and application of total flavonoids in Coreopsis tinctoria Nutt..