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Kohmei Kubo Toshiya Nakamura Keiichi Takagaki Yutaka Yoshida Masahiko Endo 《Glycoconjugate journal》1993,10(6):435-439
High molecular weight hyaluronan (M
r 400 000) obtained from human umbilical cord was depolymerized by sonication for 10 h into small molecules and finally into molecules of constant size (M
r 11 000). The molecular size of the depolymerized hyaluronan was unaltered even under different conditions of sonication. After sonication, the main sugar residues at the reducing and non-reducing termini of depolymerized hyaluronan wereN-acetylglucosamine (86%) and glucuronic acid (98%), respectively. Hyaluronans derived from rooster comb (M
r 1×106) andStreptococcus zooepidemicus (M
r 1.2×106) were deploymerized into molecules of different but characteristic sizes by sonication. On the other hand, neither chondroitin sulfate nor glycogen was depolymerized by sonication. These results suggest that high molecular weight hyaluronan may have some weak linkages related toN-acetylglucosamine in the chain, which are extremely sensitive to sonication. At present, however, the nature of these linkages is still unclear.Abbreviations HA
hyaluronan
- PA
2-aminopyridine 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(12):2001-2004
Oxidative depolymerization of chitosan induced by oxygen radical-generating systems was studied. Chitosan, but not chitin, was susceptible to oxidative depolymerization by hydroxyl radical generated through Cu(II)–ascorbate and ultraviolet–H2O2 systems in time- and concentration-dependent manners. Superoxide, H2O2, and singlet oxygen did not cause depolymerization. Metal ion chelators inhibited depolymerization by Cu(II)–ascorbate system, suggesting that the formation of chitosan–copper ion complex is important in the oxidative depolymerization. The molecular weight of the initial product during depolymerization was similar to that of glucosamine. The results suggest that copper ion could tend to coordinate to the NH2-groups at the terminal of chitosan and hydroxyl radical generated at its binding site cut off chitosan at the near position. 相似文献
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为进一步提高兽疫链球菌透明质酸产量,本实验采用分阶段控制温度工艺,当温度由36℃培养到28 h转入38℃培养至发酵结束,其透明质酸产量有很大提高。经发酵罐验证温度优化结果,其粗品产量由684 g提高到735 g。 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(12):2005-2009
Depolymerization of hyaluronic acid obtained from Streptococcus zooepidemicus by D-fructose 6-phosphate was investigated for characterization of reducing sugar-mediated degradation of biopolymers under physiological conditions. The extent of depolymerization was monitored by the decrease of viscosity of a reaction mixture containing 1.0% hyaluronic acid, D-fructose 6-phosphate, and 1.0 × 10?2 mM of Cu2+ in phosphate buffer, pH 7.4. It was found that the depolymerization of hyaluronic acid was dependent on the concentration of the reducing sugar and was specifically accelerated by the presence of Cu2+. The reaction was found to be significantly inhibited by catalase, superoxide dismutase (SOD), 1,2-dihy droxybenzene 3,5-disulfonic acid (Tiron), and chelating agents such as EDTA and diethylene triamine penta acetic acid (DETAPAC), although the inhibition by SOD was low. Almost the same depolymerization rates were observed in hyaluronic acid preparations of different molecular weight (1.1 × 106, 8.8 × 105, and 6.8 × 105). The rates, however, were different for hyaluronic acids obtained from S. zooepidemicus, rooster comb, and umbilical cord. It was concluded that depolymerization of the polysaccharide was caused by active oxygen species generated by the autoxidation of D-fructose 6-phosphate in the presence of Cu2+, in a mechanism similar to that previously reported for the degradation of DNA and inactivation of virus in vitro. 相似文献
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透明质酸(Hyaluronic acid,以下简称HA)是一种高分子粘多糖,具有良好的亲水性、生物相容性和保湿功能,广泛应用于食品、化妆品和医药领域.透明质酸的传统生产方法是主要从动物组织中提取,用微生物发酵法生产透明质酸正逐步取代传统生产方法,其优点是原料易得、成本低、所产透明质酸有更高的产量和分子量等原因. 相似文献
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透明质酸是由β(1-3)-N - 乙酰-D- 葡萄糖胺和 β(1-4)-D- 葡萄糖醛酸的双糖反复交替连接而构成的酸性黏多糖,广泛分布于脊
椎动物体内各种组织细胞间质中,具有重要生理功能。而外源性透明质酸具有理想的生物相容性和可降解性,其作为支架材料在组织工
程领域的应用具有独特优势。综述近年来透明质酸在组织工程不同领域的应用研究进展。 相似文献
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营养条件对兽疫链球菌发酵生产透明质酸的影响 总被引:15,自引:1,他引:15
透明质酸 (Hyaluronicacid ,简称HA)是N 乙酰氨基葡萄糖胺和葡萄糖醛酸以 β 1 3糖苷键和 β 1 4糖苷键连接而成的二糖单体重复构建而成的杂多糖 ,广泛存在于高等动物的结缔组织内。由于结构上的特点 ,HA具有很高的粘弹性和极强的保水性等特征 ,已被大量用于医学医药、化妆品工业[1,2 ] 。1937年Kendall[3 ] 等发现用溶血性链球菌 (Streptococcushaemolyticus)可以产生HA。其后 ,陆续发现许多能产生HA的微生物菌种 ,逐渐开发出一条可替代传统的动物组织提取法[4 ] 生产HA的新途径… 相似文献
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为了探讨电子束辐照对透明质酸功能及结构特性的影响,选择5、10、20、40、80 、100和150 kGy的电子束辐照固体透明质酸,测定透明质酸辐照前后分子量、特性粘度 、pH值、抗氧化性、紫外光谱、红外光谱、电镜图片的变化.结果表明,辐照降低透明 质酸的分子量、特性粘度、pH值;透明质酸在辐照前后的吸收特征峰没有显著的改变, 吸收强度增强;透明质酸形状随着辐照剂量的升高,由块状逐渐变成颗粒状;透明质酸 对DPPH·自由基的清除作用和还原力随着辐照剂量的增大逐渐增强.电子束辐照对透明 质酸分子结构和功能有一定的影响,但对其一级结构没有影响. 相似文献
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透明质酸产生菌的选育及发酵培养基的优化 总被引:1,自引:0,他引:1
将实验室保存UVD-34透明质酸产生菌再进行超声波处理,挑选出了一株透明质酸产量较高的菌,并对其发酵培养基进行初步优化。结果表明当可溶性淀粉质量分数为2%,复合氮源为3%,碳酸氢钠为0.1%时,其透明质酸的产量可达4.59 g.L-1,比优化前提高了1.29倍。该突变株值得进一步研究。 相似文献
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目的:改进利福平滴眼液的配制方法。方法:以计算量的盐酸溶解利福平,然后用等摩尔量的氢氧化钠中和,生成等处方量的氯化钠;并以玻璃酸钠为载体,配制利福平滴眼液。结果:该滴眼液质量稳定、可控,对眼睛无刺激性。结论:本办法设计巧妙,切实可行,既克服了的利福平的溶解困难,又解决了用乙醇作溶剂所产生的眼睛刺激性问题。 相似文献
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牛眼透明质酸的分离及性质测定 总被引:2,自引:0,他引:2
研究了牛眼透明质酸(HA)的提纯方法,采用0.125 mol/L Na2SO4取代0.1 mol/L NaCl溶解粗品,发现前者溶解液中有2个组分,一个组分被十六烷基溴代吡啶(CBP)吸附回收,产物呈纤维状,另一组分保留在溶液中并能通过分级稀释而被沉淀回收,产物呈粉末状;而用0.1 mol/ml NaCl溶解粗品,除了被CBP吸附回收外,保留在溶液中的HA不能被回收;与同类方法相比,回收率提高1.7倍以上.还分析了产物的性质,与同类样品比较,提高了纯度,降低了提纯中有机溶剂的消耗. 相似文献
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《Free radical research》2013,47(1-5):85-92
The effects of ascorbic acid, iron and ADP on hyaluronic acid, a compound present in inflamed joints, were investigated in an in vitro system. Ascorbic acid induces degradation of hyaluronic acid which increased in the presence of FeCl, and which is additionally stimulated by ADP chelated ferric ions. The hyaluronic acid degrading reactions induced by the Fe-III/ADP/ascorbic acid system were inhibited by catalase and formate to various extents whereas the presence of superoxide dismutase did not exert any inhibitory effect. Desferrioxamine, a specific iron chelator, completely inhibited hyaluronic acid depolymerisation by ascorbic acid as well as in combination with FeCl3 or FeCl3/ADP, respectively. We suggest that the ultimate hyaluronic acid degrading species is OH', generated via the Fe-III/ADP catalysed Haber Weiss reaction. There is also an indication for the involvement of perferryl or/and ferryl species in the degradation process. 相似文献
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The effects of ascorbic acid, iron and ADP on hyaluronic acid, a compound present in inflamed joints, were investigated in an in vitro system. Ascorbic acid induces degradation of hyaluronic acid which increased in the presence of FeCl, and which is additionally stimulated by ADP chelated ferric ions. The hyaluronic acid degrading reactions induced by the Fe-III/ADP/ascorbic acid system were inhibited by catalase and formate to various extents whereas the presence of superoxide dismutase did not exert any inhibitory effect. Desferrioxamine, a specific iron chelator, completely inhibited hyaluronic acid depolymerisation by ascorbic acid as well as in combination with FeCl3 or FeCl3/ADP, respectively. We suggest that the ultimate hyaluronic acid degrading species is OH', generated via the Fe-III/ADP catalysed Haber Weiss reaction. There is also an indication for the involvement of perferryl or/and ferryl species in the degradation process. 相似文献
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《Free radical research》2013,47(4):227-233
In order to determine whether exposure of hyaluronic acid to oxygen radicals caused an alteration in its properties. independent of the change in molecular weight induced. we examined its effect upon macro-phage Fc receptor binding. High molecular weight hyaluronic acid (Healon-Pharmacia) caused a dose dependent inhibition of binding between the concentrations of 0.2–1 mg/ml. At a concentration of 0.3 mg/ml both oxygen radical depolymerized and enzymatically degraded hyaluronic acid caused an inhibition of Fc receptor binding at molecular weights of 1 × 106. 1.5 × 106 and 2 × 106. Oxygen radical degraded hyaluronic acid caused a stimulation of Fc receptor binding at molecular weights of 2 × 105 and 3.5 × 105. and enzyme degraded hyaluronic acid causes stimulation at a molecular weight of 2.5 × 106. Thus this “biological property” of hyaluronic acid is dependent upon molecular weight solely and not upon the mode of depolymerization. 相似文献