| Much attention has been focused on oat β-glucans because of its multiple bioactivities. The long-range conformation and aggregation behavior of polysaccharides has stronger effects on bioactivities and pharmacological activities according to the recent studies. In this paper, β-glucans from oat planted in China was studied. The work include improvement of measurement method, purification, physico-chemical properties and molecule structure research of oat β-glucan. At the same time, in order to discuss the correlation between bioactivities and the conformation of polysaccharides, the molecule chain morphology, aggregation structure, Solution behavior, effect and its mechanism on adjusting blood glucose of oat β-glucan were also investigated with the advanced methods of isolation and purification technique, chemical and instrument analysis technique of biomacromolecular.. The main results indicated as follows:1. Studies on improved fluorometric method for the determination ofβ-GlucansThe FIA method which is a main method for the content determination of β-Glucans was improved because of its lack. In this improved method, β-Glucan was determined by fluorescence spectrophotometer after specific reaction with calcofluor. The optimum conditions of analysis were as follows: The excitation wavelengh was 344nm, emission wavelengh was 420nm, pH =10, concentration range of salt was 1%~3% and reaction time was 5min. The determination linearrange of the method was 8.0~46.0u g /mL, r = 0.997, the relative standard deviation (RSD) was 0.59% and the average percent recovery was 100.02%. The study results indicated that sugar, starch and protein didn't influence the result ofmeasurement in the improved method. At the same time, the β-Glucan content and distribution in eight oat varieties of China were determined with the improved method for the first time.. Results showed that the β-Glucan content range was 2.68%~3.87% in these oat varieties, the content of β-Glucan in oat bran was higher than endosperm and the water solution β-Glucan was the main part, in the total content.2. Purification and chemical structure of oat B -GlucanOglu-l, which was a relative homogeneous fraction, was obtained by several times deposition and column chromatography techniques. It was found that Oglu-1 was composed of glucose units only and joined by β-D- (1 - 4) and (β-D- (1-3) linkage with the linkage number ration 2.1 : 1 by using the methods of paper chromatography, UV, IR, NMR and HLPC. The molecular average-weight of Oglu-1 is 4.49 X 105 determined by CPC-LLS.3. Molecule chain morphology, Solution behavior and aggregatestructure of oat B -GlucanBy using the technique of LLS, AFM, CD, TEM, DSC, X-Ray etc, the molecule chain morphology, solution conformation and aggregate structure of Oglu-1 were studied. In addition, the three-dimensional aggregate image of Oglu-1 in solution was observed for the first time with LSCM after specific interaction with calcofluor. Results showed that the polydispersity index and 1/2 of Oglu-1 and Oglu-2 were 1.320,1.678 and 60.5nm, 51.8nm respectively. The Oglu-1 was semi-flexible chain which was proved by the Mark-Houwink equation ([ n ]=0.161Mw0585 ) and the relation model of MW-1/2. The CD spectrum shows that asymmetry, conformation and aggregation of Oglu-1 molecular could be influenced by pH, urea, DMSO, Calcofluor and temperature etc. The molecular chain conformation of Oglu-1 was observed directly by AFM, and its length, width and high of molecular chain was obtained respectively. The analysis of X-Ray diffraction and DSCindicated that the crystallinity of Oglu-1 was 27%, its set melting temperature, peak melt temperature and end melt temperature was 32.5C respectively, 85.8C and 172.5C. There are no reports about these results at present.4. Rheological properties of oat B -GlucanOn the base of pilot studies completed by other scholar, using AR-500 rheometers, the rheological properties of oat β-Glucan were studies systematicly . The results show that t...
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