Objective To optimized the ultrasonic-assisted extraction process of methyl geniposide from Mussaenda pu-bescens and investigated its antioxidant activity in vitro.Methods The yield of shanzhiside methyl ester from Mussaenda pu-bescens was used as an indicator.The optimal extraction process of shanzhiside methyl ester from Mussaenda pubescens w as ex-plored using single factor experiments and response surface methodology.The factors included methanol concentration,extrac-tion time,extraction temperature,and liquid-solid ratio.The in vitro antioxidant activity of Shanzhiside methyl ester from Mus-saenda pubescens was evaluated by the scavenging rate of DPPH free radical,hydroxyl radical,and superoxide anion free radi-cal.Results The optimal process for extracting glycosides from Mussaenda pubescens using ultrasound assisted method is meth-anol with a mass concentration of 55%,53℃extraction temperature,32∶1 liquid to material ratio,and extraction time of 98 mi-nutes.The yield of methyl ester of shanzhiside was(9.516±1.66)mL/g,and the yield of mountain hawthorn glycoside by re-gression model was 9.532 mg/g,with a relative error of less than 0.2%.After 5.5 hours of antioxidant testing reaction,4 μmol/L of geniposide methyl ester showed significant effects on DPPH·and the clearance rates of ABTS·were 95.18%and 98.75%,respectively,and the total antioxidant capacity of FRAP was 1.054 mmol/L Vc equivalent.Conclusion Response sur-face methodology can optimize the extraction process of shanzhiside methyl ester from Mussaenda pubescens,and the obtained Shanzhiside methyl ester exhibits excellent antioxidant activity in vitro.

Objective To optimized the ultrasonic-assisted extraction process of methyl geniposide from Mussaenda pu-bescens and investigated its antioxidant activity in vitro.Methods The yield of shanzhiside methyl ester from Mussaenda pu-bescens was used as an indicator.The optimal extraction process of shanzhiside methyl ester from Mussaenda pubescens w as ex-plored using single factor experiments and response surface methodology.The factors included methanol concentration,extrac-tion time,extraction temperature,and liquid-solid ratio.The in vitro antioxidant activity of Shanzhiside methyl ester from Mus-saenda pubescens was evaluated by the scavenging rate of DPPH free radical,hydroxyl radical,and superoxide anion free radi-cal.Results The optimal process for extracting glycosides from Mussaenda pubescens using ultrasound assisted method is meth-anol with a mass concentration of 55%,53℃extraction temperature,32∶1 liquid to material ratio,and extraction time of 98 mi-nutes.The yield of methyl ester of shanzhiside was(9.516±1.66)mL/g,and the yield of mountain hawthorn glycoside by re-gression model was 9.532 mg/g,with a relative error of less than 0.2%.After 5.5 hours of antioxidant testing reaction,4 μmol/L of geniposide methyl ester showed significant effects on DPPH·and the clearance rates of ABTS·were 95.18%and 98.75%,respectively,and the total antioxidant capacity of FRAP was 1.054 mmol/L Vc equivalent.Conclusion Response sur-face methodology can optimize the extraction process of shanzhiside methyl ester from Mussaenda pubescens,and the obtained Shanzhiside methyl ester exhibits excellent antioxidant activity in vitro.