Abstract: Discussing three different aqueous two-phase extractions of salidroside, selected ethanol-K₂HPO₄ as suitable aqueous two-phase system. Using wild Tibetan Rheidol crenulata as the raw material,study the condition of the ultrasound-assisted ethanol-K₂HPO₄ aqueous two-phase extraction of salidroside. Based on the single factor test,according to the Box-Behnken test design principle and response surface methodology,analyze five factors of ethanol volume fraction,liquid-solid ratio, K₂HPO₄ concentration,ultrasonic temperature, ultrasonic time,and each two of them interacted with each other on the effect of salidroside extraction rate,determine the optimal process parameters for salidroside extraction.The results showed that the highest extraction rate of salidroside was 45.4％ when the ethanol volume fraction was 51%,the liquid-solid ratio was 6 mL/g,the K₂HPO₄ concentration was 0.16 g/mL,the ultrasonic temperature was 57 ℃,and the ultrasonic time was 45 min. It is basically consistent with the predicted value of 45.1％,indicating that the regression model is effective.Compared with the ultrasound-assisted ethanol method,the extraction rate of salidroside is greatly increased.

Key words: salidroside, aqueous two-phase system, ultrasonicassit, extraction, response surface methodology