| Lycium barbarum was earliest recorded in the "Shen Nong’s Herbal classic", which has been a long history of planting and medicine, and has a history of over 2000 years till now, is formed authentic area and mainstream medicinal species. According to Pharmacopoeia of People’s Republic of China( 2010 edition, volume Ⅰ), lycium barbarum belongs to the plant family Solanaceae, the desiccative ripe fruit of lycium barbarum L.. Lycium barbarum have been used as a traditional precious Chinese herbal medicines for Used as Both Medicines and Foods, which play an important role in nourishing the liver and kidney and brightens the eye. Lycium barbarum polysaccharides is one of the main high active components of lycium barbarum. As we know, there are many kinds of lycium barbarum, and the quality of these raw material is not uniform. The content of lycium barbarum polysaccharides was measured by chemical methods, some toxic and hazardous reagents are usually used in the processing. On the other hand, the actual contents and characteristics of lycium barbarum polysaccharides can’t be reflected. The content and extraction ratio are unstable under the existing extraction process of our company, and the storage stability study of raw material was not concerned. In order to resolve these problems, the content of lycium barbarum polysaccharides measured by gel permeation chromatography( GPC) was created, with time saving, high accuracy and also can reflect the actual contents and characteristics of lycium barbarum polysaccharides. Meanwhile, the optimum extraction process were optimized and obtain the best conditions. Lycium barbarum polysaccharides of five lycium barbarum varieties was extracted based on the optimum process conditions, and screened out the raw material at the same time. The stability of polysaccharides in lycium barbarum was investigated.(1) Determination of lycium barbarum polysaccharides by gel permeation chromato-graphy have been developed. The optimal conditions of lycium barbarum polysaccharides by gel permeation chromatography was obtained: mobile phase, velocity, column and column temperature were the 0.02 mol/L KH2PO4, 0.6 m L/min, G 5000 in series with G 3000, 35℃, respectively. The limit of detection and quantification limit were 0.50 μg, 1.67 μg, respectively. The methodological validation determines that the gel permeation chromatography method had good repeatability. Lycium barbarum polysaccharides content of five lycium barbarum varieties was determined by the GPC method. The result shows that the content of the lycium barbarum polysaccharides were between 12.35 mg/g~18.84 mg/g, are lower than the determination of lycium barbarum polysaccharides content by phenol- sulfuric acid method. The GPC chromatogram indicated that the peak molecular weight of the lycium barbarum polysaccharides content of five lycium barbarum varieties are basically the same, and mainly consists of four peaks, but the lycium barbarum polysaccharides content of five lycium barbarum varieties with different molecular exist certain differences. The highest molecular weight was 920661.5 Da, the minimum molecular weight was 2978.5 Da.(2) Hot water extraction method was used to extract lycium barbarum polysaccharides, determination of lycium barbarum polysaccharides content by phenol- sulfuric acid method, orthogonal experimental design was implemented based on single-factor test. Finally, the optimum process conditions of extraction lycium barbarum polysaccharides was determined: the material liquid ratio was 1:40, extraction temperature was 100℃, extraction time was 5 h, frequency of extraction was 4 times, the content of lycium barbarum polysaccharides can be as high as 5.53%.(3) Five lycium barbarum varieties of lycium barbarum polysaccharides was extracted based on the optimum process conditions of orthogonal experimental design, the content of lycium barbarum polysaccharides are 5.38%( Lycium barbarum L summer fruit), 5.51%( Lycium barbarum L winter fruit)、4.78%( Lycium barbarum L summer fruit of Inner Mongolia), 4.24%( Lycium barbarum L winter fruit of Inner Mongolia), 3.40%( Lycium barbarum L summer fruit of Qinghai), respectively.(4) In the study, the stability of polysaccharides in lycium barbarum stored in room temperature and accelerated testing were investigated. The result shows that the content of lycium barbarum polysaccharides had a slowly declining trend as time prolonging and the quality was stable in three months under the normal temperature, but the content of lycium barbarum polysaccharides is about half of initial content and decreases rapidly with the keeping time after six months. The accelerated testing indicated that the content of polysaccharides in lycium barbarum is close to initial content in three months, the quality was stable in three months under 40℃. The polysaccharides in lycium barbarum has a good thermal stability under the room temperature and 40℃ in three months. |
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