The Extraction, Isolation And Purification, Solution Properties And Structural Analysis Of Lycium Barbarum Polysaccharide

Lycium barbarum polysaccharide is a kind of water-soluble polysaccharide extracted from Lycium barbarum. Have a variety of pharmacological effects such as immunomodulatory, anti-tumor and anti-aging. Is the main active ingredient of immunomodulatory and anti-aging. In the past, the study on Lycium barbarum polysaccharides always focus on its variety of biomedical activity and the extraction process optimization, however, is still rare for it's chemical composition and molecular spatial structure, so many of the physicochemical properties and physiological functions of Lycium barbarum polysaccharide can not be able to explain from the structure. On the basis of progress in research, this paper studied the chemical composition, solution properties and some biological activity of WLBP3-I, and also studied its chemical structure. Through the above research, we can provide a theoretical basis for the development of the Lycium barbarum functional products. The experimental results obtained are as follows:1. In this paper, Lycium barbarum polysaccharide is extracted by water,the ruscult of phenol-sulfuric acid method show that the sugar content of Lycium barbarum polysaccharide is69.74%. Three kinds of Polysaccharides (WLBP1, WLBP2and WLBP3) are obtained from separating WLBP by CTAB in a yield of25%,2.5%and30%separately. Sephadex G-150gel column chromatography and HPLC analysis show that the subfractions WLBP3-I is molecular weight homogeneity, high purity polysaccharide. The result of UV-visible spectrophotometry show that WLBP3-I was a polysaccharide complex which contain protein2. The monosaccharide composition of WLBP3-I was characterized by gas chromatography (GC). Results show that WLBP3-I contained6kinds of monosaccharides (rhamnose, arabinose, xylose, mannose, glucose and galactose), and their ratio was2.07:2.38:3.11:1.00:1.12:2.86.The average molecular weight of WLBP3-I was calculated tobe260016Da by HPLC.3. Circular dichroism and laser particle experiments that the nature of the Lycium barbarum polysaccharide solution change with the change of the polysaccharide concentration, temperature, solution pH, the metalion and the complex will greatly increase the molecular asymmetry in solution. Congo red test show that Lycium barbarum polysaccharide WLBP3-I do not exist the triple helix structure, and mainly in the form of random coil. Environmental scanning electron microscopy and atomic force microscopy results show that WLBP3-I has a high branch structure and sugar chains tangled together into rings, the main chain length of several hundred nanometers to several microns, branched-chain length of100nm-300nm range.4. The structural of WLBP3-I was studied by Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR) technology, The results show that WLBP3-I was composed of six monosaccharide and sugar ring configuration almost tobe β pyranose forms.5. The results of antioxidant experiments show that LBP has a certain of antioxidant activit.. With the different free radicals, the effect is different. The scavenging effect on superoxide anion is found to be stronger than others. Polysaccharide extracted by different methods shows different antioxidant activit, It is found that the polysaccharide ultrasonic extraction has more stronger antioxidant activit than the polysaccharide water extracted.