Purification,structural data and biological properties of polysaccharide from Prunus amygdalus gum

This work demonstrates the efficiency of almond gum polysaccharides (AGPs) as bioactive compounds. AGPs were first extracted using H₂O₂, in the presence of NaOH, at different times and temperatures. The optimal extraction conditions were 4% H₂O₂ and 2 N NaOH, for 7 h at 50 °C, leading to an extraction yield of 58.2% (w/w). After a purification step, the retained AGPs were characterised using high‐performance liquid chromatography showing a molecular weight of 99.3 kDa. The monosaccharide composition of AGPs were assessed using gas chromatography–mass spectrometry. AGPs were found to be a complex heteropolysaccharide with a repeating unit mainly composed of galactose, arabinose, xylose, mannose, rhamnose, and glucuronic acid with the respective ratios: 45:26:7:10:1:11. The acidic nature of the polysaccharide is due to the presence of glucuronic acid. Total antioxidant activity, free radical‐scavenging activity and reducing power assay of AGPs were investigated. The obtained results showed high antioxidant activities of AGPs. Furthermore, beyond 60 mg mL^?1, AGPs exhibited bacterial growth inhibition for five pathogenic strains: Escherichia coli, Staphylococcus aureus, Enterococcus feacalis, Pseudomonas aeruginosa and Salmonella typhimurium.     

Formulation and in vitro Evaluation of pH-Sensitive Cross-linked Xanthan Gum-Grafted Acrylic Acid Copolymer for Controlled Delivery of Perindopril Erbumine (PE)

A novel xanthan gum-co-acrylic acid superabsorbent hydrogel composite was formulated by free radical polymerization reaction of acrylic acid on xanthan gum. Effect of variables like dynamic swelling ratio, equilibrium swelling ratio, drug loading and drug release was investigated. Swelling ratio increases with decrease in crosslinker concentration. Drug release studies were conducted in pH 7.4 and 0.1N HCl. In acidic environment, drug release was low whereas it was sustained release in alkaline. XG4 showed significant swelling and drug release up to 24?hr. Physicochemical evaluation also confirmed it was optimized formulation. Hence XG4-co-AA was optimized for once daily dose of Perindopril Erbumine.     

分段控温黄原胶发酵过程

温度是影响黄原胶发酵的重要因素之一。为了优化黄原胶发酵过程的温度控制,在5 L通气式搅拌发酵罐中,非溶氧限制的条件下,对恒温黄原胶发酵过程进行了研究。结果显示,发酵温度为28℃时,在发酵稳定期有较高的菌体浓度,所得黄原胶的丙酮酸含量与表观粘度较高,但有较长的发酵周期。而发酵温度为33℃时,有较短的发酵周期,在发酵稳定期有较高的比产胶速率,但所得黄原胶的丙酮酸含量与表观粘度较低。实验测定了控制黄原胶发酵生长期温度为28℃,稳定期温度为33℃的发酵过程数据。结果表明,与恒温发酵过程相比,通过温度的分段控制可以缩短发酵周期,提高产胶浓度及改善胶的品质,分段控温是黄原胶发酵的一种方便有效的调节手段。     

香豆胶衍生物的化学结构及稳定性研究

将市售商品溶于水,用异丙醇沉析提纯,溶于0.1 mol/L NaNO3纯水溶液中,经0.5μm滤膜过滤后用水相凝胶渗透色谱法(GPC)测定,测得香豆胶(FG)、羟丙基香豆胶(HPFG)、阳离子香豆胶(CFG)的数均、重均相对分子质量Mn、Mw分别为:1.19×105、3.36×105,8.52×104、2.85×105,9.33×104、2.87×105。用甘露聚糖链在碱性条件下醚化时发生降解,解释两种改性FG的相对分子质量较FG低而多分散性(Mw/Mn)较FG高的测试结果。认为商品FG的1%水溶液黏度(1300 mPa.s)高于商品HPFG和CFG(分别为705和610 mPa.s)的原因是前者相对分子质量较高且残渣含量也较高(~10%,后二者为1%~2%)。HPFG的取代度为0.12,根据文献发表的13C-NMR数据确认HPFG分子链上羟丙基取代位置为C6。讨论了香豆胶(半乳甘露聚糖)的化学结构。热重分析法测定的热稳定性,HPFG高于CFG,CFG又高于FG。图6表3参13。     

The emulsifying properties of a polysaccharide isolated from the fruit of Cordia abyssinica

Polysaccharide was isolated from Cordia abyssinica and its effect, at differing concentrations, on its emulsifying ability was determined. Emulsions of vegetable oil containing up to 1% of the polysaccharide in phosphate pH 7.4 buffer, were prepared by using a hand piston homogenizer. Emulsification was assessed by diluting samples of the emulsions in sodium dodecyl sulphate and measuring absorbance at 500 nm. Addition of increasing concentrations of the polysaccharide up to 1% enhanced emulsification and emulsion stability. Above 1% concentration the polysaccharide solutions were too viscous for making emulsions conveniently. At a constant concentration of the polysaccharide, addition of up to a 1% concentration of salt enhanced emulsion formation. Further addition of salt above 1% resulted in no further changes in emulsifying ability, but the stability of the emulsions formed decreased on increasing the concentration of salt above 1%. The effect of pH on emulsifying ability was investigated by preparing emulsions using buffers of different pH, from pH 3 to pH 13. The polysaccharide had poor emulsifying ability below pH 7. Emulsifying ability increased with pH between pH 7 and 11. At pH above 11 there was a decrease in emulsifying ability.     

黄原胶接枝共聚物降滤失剂应用性能评价

黄原胶（XG）具有优良的耐盐性和增稠降滤失性能，但耐温性较差。对XG分子结构的分析认为，可利用XG链上的活泼基团接枝丙烯酰胺等乙烯基单体，增强其耐温性能，用作耐温抗盐钻井液处理剂。对比了合成的黄原胶丙烯酰胺等接枝共聚物（XGG）降滤失剂与XG在淡水、4％盐水和饱和盐水钻井液中的增粘降滤失性能和抗温性能，并通过岩心膨胀试验对比了XGG、XG和KCl对页岩的抑制性能。试验结果表明，在淡水钻井液中XGG具有极强的增粘效果和降滤失能力，远远超过XG1随着钻井液矿化度的提高，XGG的性能有一定下降，但XGG在各种钻井液中均具有比XG更好的高温增稠和控制失水的能力；XG已具有优良的抑制性，XGG的抑制性得到进一步提高。     

碘与淀粉的相互作用及在Vc分析中的应用

本文探讨了碘与淀粉的相互作用以及碘－淀粉显色体系的稳定性。结果表明：在碘量一定时，体系的吸光度随淀粉用量的增大而增大，最后趋向稳定；在淀粉量一定时，体系的吸光度随碘用量的增大而增大，最后亦趋向稳定。碘－淀粉显色体系很不稳定，吸光度随时间呈比较明显的下降趋势，但加入复合表面活性剂可以使显色体系的稳定性大大提高。在上述结果的基础上，我们建立了测定Ｖｃ的新方法，此法具有简单、快捷、试剂易得、灵敏度高以及对浑浊试液不必分离即可直接测定等优点。该法的灵敏度为０．２５μｇ／ｍｌ，对１μｇ／ｍｌ的Ｖｃ试液进行平行测定，１０次平行测定结果的相对标准偏差为８．８６％，加标回收率为９０．５％－９３．６％，用于番石榴汁饮料中Ｖｃ的测定，结果满意。     

户外像素管软质灌注胶的研制与应用

采用脂环族环氧树脂、柔韧性环氧树脂、改性脂环胺类固化剂为主要原料，研制出户外像素管灌注软胶，产品具有耐紫外线辐照、耐冷热冲击、粘接性好等特点。介绍其制备方法、性能及用。     

浩伦松碱合剂防治柑桔蚧壳虫的田间应用

通过在3个省份的田间试验充分表明，浩伦松碱合剂是防治柑桔蚧壳虫的良好药剂。推荐使用45％浩伦松碱合剂4500—5625mg／kg的剂量较好，在药后15d对柑桔蚧壳虫的防效为86．95％～89．11％。     

羧甲基纤维素钠/阳离子瓜尔胶共混膜用作药物缓释材料的研究

以可生物降解和生物相容的羧甲基纤维素钠(NaCMC)与阳离子瓜尔胶(GG)为原料,制得系列不同配比的多糖共混膜。以此共混膜作为药物布洛芬的载体,考察了共混比、药物浓度以及pH值对药物释放的影响,并研究了其药物释放机理。结果发现,对布洛芬药物释放影响最大的是介质的pH值,其次是共混膜的共混比例,药物含量在弱碱介质中有一定的影响,在酸性介质中基本无影响。大部分的药物释放n>0.89,为非Fick扩散(骨架溶蚀机制),药物以零级进行释放。共混膜对疏水性药物布洛芬具有较好的缓释性能。