| With Usnea from high elevation areas as the subject, the research of morphology, the op-timum for extraction and purification of polysaccharides, physical and chemical properties, molecular weight and the capacity of scavenging DPPH.Some research results presented as following:1. Improvement of paraffin section methods and morphological studies on Usnea betulina:Some improvements about the Usnea′s manufacture of paraffin section were put forward to according to problem existing in the traditional paraffin section preparation. With Usnea betulina Mot. from high elevation areas as the subject,based on the research of material selec-tion,fixation,dehydration, infiltration,embedding,section and dye of its tissues,clear paraffin sections were made and staining was processed. The characteristic, microscopic trait and transverse section of tissue structure were studied, and according to the identity of hyphae made us understand the range of structure: the cortex, the algal layer, the medulla and the cen-tral cord. The cortex′s hyphae are usually oriented in various directions and so compressed as to appear cellular. The algal layer is composed of scattered clumps of algae and loosely in-terwoven hyphae. The medulla is composed of loosely interwoven hyphae. The central cord is composed of compressed hyphae.2. Optimum process of extracting polysaccharide of Usnea montis-fuji by hot water and de-protein:The optimization process conditions of extraction temperature, ratio of solid-liquid,the duration of time and the extraction of times in extraction polysaccharides from Us-nea.montis-fuji,has been undertaken by orthogonal experiment of L9(34).And optimum tech-nological conditions are as follows:temperature is 80℃, ratio of solid-liquid is 1:5, the dura-tion of time is 2h and times of the extraction is twice. The comparison of the methods of eliminating protein: the traditional Sevag method and 10 % Trichloride acetic acid method were used to eliminate protein from the tough polysaccharide of U.montis-fuji .The Sevag method was chosen through comparing the elimination ratio of protein and the loss ratio of polysaccharides.Optimum technological conditions of Sevag method: the ratio of polysaccha- rides and sevag solution is 3:1, the duration of time is 2h and times of eliminating protein is twice.3. Extraction and purification, physical and chemical properties, molecular weight:With U.longissima in Tibet and Dongbei areas, U.diffracta in Dongbei areas, U. mon-tis-fuji in Qinling and U.subfloridana in Xinjiang province as the subject, we study the ex-traction and purification, physical and chemical properties, molecular weight offive kind of polysaccharides. Results presented as following:(1) The comparison of extraction ratio: U. montis-fuji >U.subfloridana >U.diffracta >U.longissima in Dongbei areas > U.longissima in Tibet.(2)The five types of Usnea polysaccharides was purified with DEAE-52cellulose and Sephadex colum,each of them is seperated into three composition.(3) Their weight-average molecular weight is about 3.0×10~6～4.0×10~6,their number-average molecular weight is about 2.0×10~6～3.0×10~6, the molecular weight of U.subfloridana polysaccharides is higher than others′.4. Study on the capacity of scavenging DPPH of five types of polysaccharides:The USM,USLD,USLX,USS,USD have capacity of scavenging DPPH .Within certain range of concentration of polysaccharides,the capacity increase corresponding to the increase of concentration .But the the capacity of scavenging DPPH, USM,USLD,USLX,USS,USD is all deeply lower than Vc.The composition of USM,USLD,USLX,USS,USD have capacity of scavenging DPPH, and their capacity is equal to Vc.
|
PDF Full Text Request