Extraction And Structure Characterization Of Polysaccharides Compounds From Tobacco Stem

This paper studied the extraction method of polysaccharides compounds from tobacco stem,and make a preliminary analysis of the structure of polysaccharide extract. The results showed that:1. Use the improved method of "solvent extraction"to explore the extract of tobacco stems polysaccharide,Orthogonal shows that the best extraction process of tobacco stems polysaccharides is temperature of 220℃, extracts 85 percent concentration, reaction time 90 min, selected on the first catalyst,the extraction rate of tobacco stems polysaccharide up to 5.8114%.And compared to ordinary "solvent extraction", polysaccharide extract from this method without nucleic acid, amino acids and proteins,eliminating the subsequent extraction of amino acids and protein steps.2.UV spectrum analysis shows that tobacco stems polysaccharide in the 200nm-400nm frequency range,without UV absorption. There is no the electronic transfer betweenπ→π^*,it means no conjugateπbond or benzene structure,tobacco stems polysaccharide without nucleic acid, amino acids and proteins. Infrared spectral analysis showed that: in the area of 4000-400cm^-1, about 3400cm^-1 (O-H stretching vibration),about 2930cm^-1 (C-H stretching vibration),about 1420cm^-1(C-H bending vibration)have absorbed. This three-absorption peak is the features absorption peak of polysaccharide,so we get the conclution that the extract is polysaccharide. Luoyang and Xuchang tobacco-producing areas of polysaccharide extract mainly fromα-pyran-ring composed of sugar,isα-glucoside bond;nanyang tobacco-producing areas of polysaccharide extract stem mainly fromβ-furan sugar ring,isβ-glucoside bond. Polysaccharide extract from three tobacco-producing areas all contain sulfur;and the tobacco stems polysaccharide from luoyang tobacco-producing areas with sulfate,it means a kind of sulfate polysaccharide.3.Gel permeation chromatography spectrum and the results show that:tobacco stems polysaccharide extract of luoyang with the polysaccharide components of relative molecular mass of 34690Da,2796Da and the 1123Da,distribution are 2.48,2.27and1.52;tobacco stems polysaccharide extract of xuchang with the polysaccharide components of relative molecular mass of 3993Da,2426Da and 1347Da,distribution are 1.98,2.01 and 1.82;tobacco stems polysaccharide extract of nanyang with the polysaccharide components of relative molecular mass of 42569Da, 2747Da and the 1159Da,distribution are2.51,2.26and1.56.Relatively broad molecular weight distribution, three by polysaccharides by the extract of all miscellaneous xylanase.4.Through the scanning electron microscope of polysaccharide extract,we know that:three tobacco stems polysaccharide samples larger difference under the micro-structure. Tobacco stems polysaccharide from luoyang showing a micro-particle sizes,look for dipper-like, a rough surface and a porous structure of concave. particle sizes is different,Cross-section is about 2.3×2.5μm,thickness is about 0.4μm;.Tobacco stems polysaccharide from xuchang showing a Spherical,surface is smooth,the balls diameter of different sizes is about 0.2-0.6μm;.Tobacco stems polysaccharide from nanyang showing Cellular-type appearance,Surface covered with different forms of concave structure. The elements results showed that Polysaccharide composed of extracts from a single element of comparison,C and O is the main element,C element is higher than other element,S element is lower. Xuchang and Luoyang, which the tobacco polysaccharides containing extracts of the trace element Cl.