Optimization of ultrasonic-assisted extraction of total flavones from Coreopsis tinctoria Nutt.

The conventional extraction methods for flavonoid were time-consuming, laborious and energyconsuming. In this article, ultrasonic-assisted extraction (UAE) was utilized to extract flavonoid from Coreopsis tinctoria Nutt. The factors influencing the extraction efficiency were studied, including the effects of ultrasonic power, extraction time, a ration of materials mass and extraction temperature. By single factor design and response surface methodology (RSM) experiments, the optimum experimental parameters were determined: extraction temperature 70°C, extraction time 62min, a ratio of water to raw material 55mL/g and ultrasonic power 460W,under the most suitable conditions, a maximum yield of total flavonoids 10.90% can be achieved. UAE was an effective way to extract flavonoid from Coreopsis tinctoria Nutt. This technology required short time, less laborious and energy, resulting in low cost and friendly environment.