Abstract: The ultrasound extraction process parameters of total triterpenoids from Synsepalum dulcificum leaf from Hainan province was optimized by response surface methodology. The experiments were arranged according to Box-Behnken central composite experiment design. Four independent influencing factors of extraction, such as concentration of ethanol, extraction temperature, the ratio of liquid to solid and ultrasonic time, were considered on the basis of single factor experiments. The results showed that the optimum ultrasound extraction conditions for total triterpenoids were as follows: concentration of ethanol 70%, extraction temperature 50 ℃, the ratio of liquid to solid 30:1(mL:g) and ultrasonic time 33 min. The experimental yield (0.92%) was in good agreement with its predicted value (0.94%) by model.

Key words: Synsepalum dulcificum leaf, response surface methodology, total triterpenoids, ultrasound extraction