Urea-based deep eutectic solvents enzyme system for high efficiency extraction of alkaloids and flavonoids in plants: Zanthoxylum nitidum (Roxb.) DC. as a case

In this work, an enzymatic digestion urea-based solvent system was developed to extract alkaloids and flavonoids in Zanthoxylum nitidum (Roxb.) DC (ZN). A total of 50 DESs were prepared and their extraction rate were screened, and the enzyme conditions affecting the rate were also evaluated. As a result, it was found that the Ur/Pa based cellulase system owned the best extraction efficiency in ZN with the rate of 34.56 ± 1.09 mg/g, which was higher than the methanol. Optimized using the one factor experiments and response surface methodology (RSM), the best condition was 27 % water content, 35 min extraction time, 39℃ extraction temperature, 25:1 solid/liquid ratio, 1.3 mg/mL enzyme concentration. The scanning electron microscopy (SEM) results showed that the Ur/Pa based cellulase system entirely destroys the cell wall of ZN, with excellent extraction rate. This study developed a new design of DESs in extraction of alkaloids and flavonoids in ZN.