Study On Oligosaccharides Synthesis Under Microwave Radiation In Solid State And Its Biological Value

Oligosaccharides are usually synthesized by enzymes, it takes a long time andhas low yield. The current chemical synthesis of oligosaccharides usually havehigh cost and bothering purification steps. Oligosaccharides synthesis undermicrowave radiation in solid state has a rapid speed and high yield , it also has noenvironment pollution. In this thesis, oligosaccharides were synthesized undermicrowave radiation in solid state, glucose as the reactant,acid A as the catalyst.Proper methods of synthesis technology conditions under microwave irradiationswere studied. The synthetic oligosaccharides was crude purified and its biologicalvalue was studied. At last the security of synthetic oligosaccharides was also studiedin this article.Firstly, the optimum reaction conditions were investigated by single factorexperiment and orthogonal test as follows: microwave power 1000w ,microwaveirradiation time 9 min, adding 30% water to initiate reaction, adding 4% acid A asthe catalyst. The yield of product was 77%. The product was characterized by HPLCanalysis. The constituter of product was established as follows: disaccharides20.81%,trisaccharides15.50%,tetrsaccharides10.84%, pentsaccharides7.79%, hexsaccharidesand other polysaccharides21.63 %. The constituter of monose, disaccharides andtrisaccharides was established as follows: glucose49.25% ,unknown1.48%,maltose10.10%, isomaltose21.78%, maltotriose2.15%,panose10.08%, isomaltotriose5.16%。The synthetic oligosaccharides were crude purified by GPC. Three constitutionswere got as F3, F2 and F1.The constituter of F3 was established as follows:pentsaccharides and hexsaccharides 55.4%, trisaccharides and tetrsaccharides6.8%,other polysaccharides 37.8%. The constituter of F2 was: hexsaccharides21.8%,pentsaccharides34.4%, tetrsaccharides48.4%. F1 was: trisaccharides21.8%,disaccharides36.4%, glucose 41.8%.The synthetic oligosaccharides have antibacterial effects on Bacillus subtilis,Staphylococcus aureus and Pseudomonas aeruginosa ,but they also have effects ofincreasing the growth of E.coli .The synthetic oligosaccharides have better effectthan isomaltose (IMO-500) in the hygroscopicity and moisture retention, they are84%and 68% for each other. Moreover, over 90% components of the product can'tbe hydrolysated by α--amylase.The level of serum glucose of the normal mice can be increased by the crudeproduct . but the content of serum total cholesterol and the GSP (P<0.05)in thenormal mice can be significantly reduced by the crude product with the control.At last, according to the experiment of acute toxicity and accumulated toxicityof synthetic oligosaccharides to the normal mice , the synthetic product be provedsecurity.