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Preparation of Chitooligosaccharides and Their Effects in Vivo

Author: ZengLinTao
Tutor: ZuoCaiQin
School: Central China Normal University
Course: Organic Chemistry
Keywords: Chitosan Chitooligosaccharides Enzymatic hydrolysis Structural characterization Molecular weight Thermal stability Biodistribution Biological activity Trace elements
CLC: R943
Type: Master's thesis
Year: 2007
Downloads: 502
Quote: 6
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Abstract

Different molecular weight chitosan very different nature, and and Chitosan many unique features manifested only molecular weight is reduced only to a certain extent. However, in the usual case, the low molecular weight of chitosan in the preservation process perishable and difficult to preserve. Looking scale production of a stabilized shell oligosaccharides having biological activity caused a concern in many countries. This article provides an overview of the research progress of home and abroad in recent years in the preparation and biological activity of chitooligosaccharides function. Analysis using high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (H-NMR, C-NMR), thermal gravimetric analysis (TG) and differential thermal analysis (DTA) and other modern means of characterization of the enzyme SYSTEM shell oligosaccharide molecular weight and chemical structure. Kunming mice of different molecular weight chitosan tissue distribution in mice in vivo study of mice trace elements. The main contents and conclusions are as follows: 1. α-amylase catalyzed hydrolysis series shell of chitosan oligosaccharides. 3% of chitosan by weight of the α-amylase can be within 6h deacetylation degree of 85.5% chitosan is degraded into water-soluble shell oligosaccharides. The degree of deacetylation of chitosan before and after degradation remain basically unchanged. HPLC analysis showed that the, these enzymatic hydrolysis of chitosan may be mainly within cut manner on chitosan. The thermal analysis results show that the degradation obtained chitooligosaccharides decrease in molecular weight, thermal stability weakened. 2. The chitooligosaccharide usually easy discoloration metamorphism, only cryopreservation. The use of UV-Vis Spectra of various chitooligosaccharides discoloration may affect factors such as the temperature, time, pH, relative humidity, oxygen, and a reducing agent. As the temperature increases, the chitooligosaccharide browning speed up; relative air humidity is conducive chitooligosaccharide browning; very significant effect of pH on the browning. The infrared spectrum and solubility test results showed that the browning of its CHITOOLIGOSACCHARIDE has a great influence on the structure and properties, the structure of the product after browning changed, its solubility and hygroscopicity also will deteriorate. Therefore, we propose to save CHITOOLIGOSACCHARIDE suitable conditions: low temperature, low relative humidity, oxygen-free, pH below 4 or above 10.3. With dilute hydrochloric acid solution as a solvent to dissolve the chitosan, research in the structure of the conditions as well as the product of the hydrolysis action of the enzyme degradation of chitosan. Hydrochloric acid and chitosan amino molar ratio equal to 0.90, more suitable for the enzymatic degradation of chitosan. Oligosaccharide hydrochloride thermal stability of the resulting product than the corresponding acetic acid salt thereof, in the preservation process is not easy browning. Degradation process of the method is simple, easy to handle product, low cost and stable product, it is an ideal method suitable for large-scale production of chitooligosaccharides. 4. In order to study the molecular weight of the chitosan and its water-soluble to its absorption in the gastrointestinal tract as well as in vivo distribution of three different molecular weights Mw (HCS 7.60 × 10 ~~ 5 of MCS 3.60 × 10 4 and LCS5. 30 × 10 ~ 3) series of chitosan and a water-soluble chitosan (WSC, Mw 3.91 × 10 ~ 4) as experimental materials to investigate the absorption and distribution in the body. The results show that: the chitosan can be mice absorption, absorption is affected by the molecular weight and water soluble. With the increase in the molecular weight of chitosan, the intestinal absorption weakened; chitosan the solubility increase to to enhance intestinal its absorption. Chitosan distributed to the liver, kidney, spleen, thymus, heart, blood and lung, but the concentration in the liver is significantly higher than other organizations, of chitosan in the liver have a certain cumulative. 5. Kunming mice experiments, the use of oral mice continued medication for 90 days, the dose of 1.50 g / (kg.bw.day) to explore were long-term use of different molecular weight chitosan on trace elements in the body. The results showed that: the long-term use of the medium molecular weight chitosan (Mw 3.60 × 10 ~ 4) have improved the trace elements Fe and Zn content in the body in the liver and spleen, respectively, taking a high molecular weight chitosan (Mw 7.60 × 10 ~ 5), the water-soluble medium molecular weight chitosan (Mw of 3.91 × 10 ~~ 4), the low molecular weight chitosan (Mw of 5.30 × 10 3), trace elements as measured in vivo had no significant impact.

Preparation of Chitooligosaccharides and Their Effects in Vivo

Abstract

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