Studies On The Extraction,Isolation,Purification And Bioactivities Of Polysaccharide In Xinjiang Mulberry Leaves

Morus nigra L.belongs to the black mulberry species of mulberry in the family of mulberry.Distributed in southern Xinjiang,has been used as uygur folk medicine for anti-inflammatory,blood tonic and other medicinal effects.Modern studies have found that mulberry leaves are rich in alkaloids,flavonoids,polysaccharides,proteins and other substances.Among them,polysaccharide has obvious effects of hypoglycemic and immune regulation.Taking medicine mulberry leaves as the main raw material,by the method of orthogonal experiment,the polysaccharide extraction process is optimized,grading is determined by the HPLC-ELSD method alcohol sink in the monosaccharide composition,USES the AB-8 macroporous resin on the alcohol after heavy crude polysaccharide decoloration,protein processing,the DEAE-Sepharose Fast Flow ion exchange column separation for coarse polysaccharide,finally by dextran gel G-100 purification.Two polysaccharide components with relatively uniform molecular weight(MPS-IV-1 and(MPS-IV--2)were obtained.In addition,DPPH free radical scavenging,ABTS free radical scavenging,reduction force determination,in vitro inhibition of alpha-glucoglycoside enzyme,inhibition rate of Hela cells and other related activities of alcohol-precipitation polysaccharide and homogeneous polysaccharide were studied.The main results are as follows: 1.The optimal extraction process of polysaccharides from mulberry leaves was solid-liquid ratio 1:30(g/mL),extraction time 3h,temperature 90 ℃,and yield 8.98%.The highest content of polysaccharides in ethanol samples was 37.8% under 95% concentration of ethanol.HPLC-ELSD method was established to analyze the composition of monosaccharide in mulberry leaf polysaccharide.After hydrolysis of polysaccharide components by trifluoroacetic acid,the mobile phase was acetonitrile/water(V:V=80∶20),iso-elution was conducted at a flow rate of 0.8 mL/min,column temperature was 30℃,drift tube temperature was 60℃,and nitrogen was used as carrier gas at a flow rate of 3.0 L/min.Within 30 min,all five monosaccharides including arabinose,xylose,fructose,rhamnose and glucose were completely separated.Under this condition,the composition of monosaccharide of different components was determined by fractional alcohol precipitation.Remove DPPH free radicals,remove ABTS free radicals,reducing force measurement,alpha glycosidase enzymes in vitro inhibition,Hela inhibition ability best constituents of MPS-Ⅳ,MPS-Ⅲ,MPS-Ⅱ,MPS-Ⅰ,MPS-V.2.Two polysaccharide components of MPS-IV-1 and MPS-IV-2 were isolated from the crude polysaccharide of mulberry leaves under the condition of 80% ethanol concentration.Gel permeation chromatograph(GPC)-multi-angle laser light scattering(MALLS)coupled to the determination of molecular weight of 12.16 KDa,5.43 KDa respectively.MPS-IV-1 contains rhamnose,arabinose,fructose,glucose and galactose.MPS-IV-2 is composed of arabinose,glucose and galactose.The structures of MPS-IV-1 and MPS-IV-2 were characterized by infrared spectroscopy.MPS-IV-1 and MPS-IV-2 showed some inhibitory activity against alpha-glucosidase.