Study On Extraction Of 1-Deoxynojirimycin From Mulberry Leaf By Cellulase And Ultrasonic Method

1-Deoxynojirimycin(DNJ),one of the poly-hydroxylated alkaloids,is known to inhibit ?-glucosidase with potential antidiabetic applications.It can hinder the decomposition of disaccharides and delay the growth of glucose,fructose and other monosaccharides into the blood,reduce the role of blood sugar,has a good prospect in medicine.In this paper,content of DNJ in mulberry leaves was determined by HPLC.The content of DNJ in mulberry leaves at different leaf positions in different months was explored.It was found that the content of DNJ in the leaves was the highest in July and August,which provided a theoretical basis for DNJ extraction.The optimum extraction conditions of the traditional extraction method of acid extraction were obtained as follows:the extraction temperature was 50 ?,the pH value of the extract was 4.0,the mass concentration ratio of the liquid was 0.0167 g/mL,and the extraction time was 2.0 h.Under these conditions,the extraction rate of DNJ was 0.0791%.The cellulase assisted extraction process was optimized by single factor and response surface experiments.Then the optimal extraction conditions were as follows: extraction temperature 60 ?,pH value of extraction solution 3.8,mass concentration of liquid 0.0170 g/m L,the concentration of enzyme was3.4 mg/mL and the extraction time was 1.0 h.Under this condition,the extraction rate of DNJ was 0.0950 %,which was 20.1 % higher than that of acid extraction.The source of cellulase can be cultivated for Trichoderma reesei production,and the fermentation conditions are optimized to improve the enzyme activity.Ultrasound in the bioactive substances in the process of extraction of the advantages are increasingly prominent.In this paper,the method of ultrasonic assisted cellulose enzymatic treatment of mulberry leaves to extract the DNJ,found that the extraction rate has been previously improved.The extraction conditions are optimized as follows: put the mulberry leaves and cellulase solution in 3.4 mg/mL together at the ratio of material to liquid in 0.0170 g/mL.The pH of the solution was adjusted to 3.8.After mixing,the mixture was placed in an ultrasonic cleaner(water content of 8 L)set at 45 ? for 4 min.Water bath for 56 minutes after centrifugation to take the supernatant,precipitation according to the same conditions extracted one more time,the process conditions to get the DNJ extraction rate of 0.1066 %.