Process Optimization for Combined Extraction of Polysaccharide,Flavones and Alkaloid from Mulberry Leaves by Response Surface Methodology

To obtain active substances from mulberry leaves efficiently,we first extracted polysaccharide and flavones from mulberry leaf by hot water method,and then extracted alkaloid from mulberry leaf using ethanol-hydrochloric acid solution.The combined process for extracting these three active substances from mulberry leaf was optimized by response surface methodology.The optimized condition for extracting polysaccharide and flavones from mulberry leaf was extraction time 93 min,extraction temperature 81 ℃,mass concentration of raw material 0.05 g/mL,and 4 times of extraction.Under this condition,the actual extraction yield of polysaccharide and flavones was 5.574% and 2.693%,respectively.The optimized condition for extracting alkaloid from mulberry leaf was extraction time 142 min,mass concentration of raw material 0.04 g/mL,volume fraction of ethanol 26.0%,and 3 times of extraction.Under this condition,the actual extraction yield of mulberry leaf alkaloid was 0.398%.The result indicated that the established model had good fitting performance,and could be used to predict the extraction yield of active substances from mulberry leaves.