Study On The Extraction And Separation Technology Of Alkaloids And Polysaccharides In Mulberry Leaves

The mulberry plant belongs to the family Moraceaein the Morus L,which was first included in"Classic of Poetry"and also known as"iron fan".The cultivation of mulberry trees has a very long history in China,which was reported by the National Ministry of Health as medicinal and food plant.The use of mulberry leaves for medicinal purposes was first recorded in the Shen-Nong classical text on Chinese herbal remedies.Mulberry leaves have antioxidant,lowering the content of blood sugar and other kinds of pharmacological efficacy.1-deoxynojirimycin,i.e.,1-DNJ is one of the alkaloids substances in mulberry leaves,which has a good influence on lowering blood sugar.Polysaccharide in mulberry leaves were composed of monosaccharide and disaccharide,which have good competitive inhibitors of á-glycosidase enzymes and can promote the secretion of insulin by ? cells,which also achieves the effect of lowering blood sugar.In the experiments,the extraction and separation technology of 1-DNJ and polysaccharides in mulberry leaves was investigated on the basis of laboratory study.Firstly,response surface experiment analysis was employed to optimize the pilot-plant extraction of 1-DNJ in mulberry leaves.The results indicate that the optimum pilot-plant conditions for the extraction of 1-DNJ are a temperature of 79?,an extraction time of 88 min and a sample:solvent ratio of 1:9.8.The actual measured concentration of 1-DNJ under these optimized conditions is 31.62 mg g ~1 and is basically consistent with the predicted value of 32.03 mg g ~1.Response surface experiment analysis was also employed to optimize the pilot-plant extraction of polysaccharides in mulberry leaves.The results indicate that the optimum pilot-plant conditions for the extraction of polysaccharides are a temperature of 77?,an extraction time of 112 min and a sample:solvent ratio of 1:20.The actual measured concentration under these optimized conditions is 105.57 mg g ~1polysaccharide crude product and is basically consistent with the predicted value of 106.64 mg g ~1.The relative error is about 1%.The experiment explores the separation and purification process of1-DNJ in mulberry leaves.In the end,001×7(732)ion exchange resin was chosen as the best resin for the separation of 1-DNJ.The method of 201×7anion exchange resin was chosen for the purification of 1-DNJ.The spray drying conditions were examined for 1-DNJ and the results showed that uniformity solid powder can obtained in the conditions of a hot air temperature of 180?,a speed of peristaltic pump of 3 r min ~1,a fan frequency of 50 Hz and a material concentration of 60 mg mL ~1.Ultimately,the extraction,separation and purification preparation technology was determined and after those processes,the content of 1-DNJ solid product of13.6%was obtained.The spray drying conditions were screened in the experiment.The single factors of hot air temperature,peristaltic pump speed,fan frequency and material concentration were studied on the effect of polysaccharide content in solid powder.The experimental results indicate that the best spray drying conditions of polysaccharide are a hot air temperature of 180?,a speed of peristaltic pump of 3 r min ~1,a fan frequency of 50 Hz and a material concentration of 50 mg mL ~1.Ultimately,the extraction and separation preparation technology was determined and after those processes,the content of polysaccharides solid product of 10.6%was obtained.