2-羟基-3-磺酸基丙基细菌纤维素醚的合成

以细菌纤维素为原料,合成2-羟基-3-磺酸基丙基细菌纤维素醚,采用红外光谱仪对产物结构进行了分析,用正交设计法研究了2-羟基-3-磺酸基丙基细菌纤维素醚合成的最佳工艺条件。结果表明,在优化条件下合成的2-羟基-3-磺酸基丙基细菌纤维素醚交换容量为0.481 mm ol/g。     

Synthetically Tuning the 2‐Position of Halogenated Quinolines: Optimizing Antibacterial and Biofilm Eradication Activities via Alkylation and Reductive Amination Pathways

Agents capable of eradicating bacterial biofilms are of great importance to human health as biofilm‐associated infections are tolerant to our current antibiotic therapies. We have recently discovered that halogenated quinoline (HQ) small molecules are: 1) capable of eradicating methicillin‐resistant Staphylococcus aureus (MRSA), methicillin‐resistant Staphylococcus epidermidis (MRSE) and vancomycin‐resistant Enterococcus faecium (VRE) biofilms, and 2) synthetic tuning of the 2‐position of the HQ scaffold has a significant impact on antibacterial and antibiofilm activities. Here, we report the chemical synthesis and biological evaluation of 39 HQ analogues that have a high degree of structural diversity at the 2‐position. We identified diverse analogues that are alkylated and aminated at the 2‐position of the HQ scaffold and demonstrate potent antibacterial (MIC≤0.39 μm ) and biofilm eradication (MBEC 1.0–93.8 μm ) activities against drug‐resistant Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecium strains while demonstrating <5 % haemolysis activity against human red blood cells (RBCs) at 200 μm . In addition, these HQs demonstrated low cytotoxicity against HeLa cells. Halogenated quinolines are a promising class of antibiofilm agents against Gram‐positive pathogens that could lead to useful treatments against persistent bacterial infections.     

鲎试剂方法检测胎盘多肽注射液中细菌内毒素

考察采用鲎试剂方法检测胎盘多肽注射液中细菌内毒素的可行性.参照中国药典2010年版(二部)附录ⅪE细菌内毒素检查法,选择两个厂家生产的鲎试剂(灵敏度为0.5 EU/mL),对不同稀释倍数的胎盘多肽注射液供试品溶液进行细菌内毒素与鲎试剂之间凝集反应的干扰试验.结果显示胎盘多肽注射液经40倍稀释后对鲎试剂与细菌内毒素之间的...     

三种抗生素注射剂的细菌内毒素检查法研究

对云南省生产的８６批注射用青霉素钠、７５批硫酸卡那霉素注射液和２６批盐酸林可霉素注射液进行了中国药典规定的家兔法与细菌内毒素检测法之间的对比考察，两者的符合率均为１００％．     

Prospecting Exopolysaccharides Produced by Selected Bacteria Associated with Marine Organisms for Biotechnological Applications

In this study, bacteria associated with marine organisms were screened for the production of exopolysaccharides(EPSs) on MY media containing sea salts(2.5%-10%). Three selected isolates were identified as Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26 using 16 S r RNA gene sequencing. Optimization of the growth and EPS production kinetics in relation to incubation time were assessed. The purified EPS yield was 590, 650 and 540 mg·L-1 culture media respectively in Alteromonas sp. PRIM-21, Nitratireductor sp. PRIM-24 and Enterobacter sp. PRIM-26. Biochemical and FTIR analyses revealed the presence of biologically important functional groups in the EPS produced by all the three isolates. The EPS produced by Nitratireductor sp. PRIM-24 and Alteromonas sp. PRIM-21 showed 2.0% sulfate content. These bacterial EPS also showed antioxidant and emulsifying activities and the EPS produced by Enterobacter sp.PRIM-26 showed significantly higher antioxidant activities in terms of superoxide(IC50 0.33 mg·mL -1) and DPPH(IC50 0.44 mg·mL -1) radical scavenging. It also showed higher emulsifying activities against selected hydrophobic substrates with EI24 values above 60%. From the results of the study, it can be concluded that the isolated bacteria produce EPS that can be investigated in detail for biotechnological applications.     

Stereoselective Synthesis,Configurational Assignment and Biological Evaluations of the Lipid Mediator RvD2n-3 DPA

Herein we report the first total synthesis of RvD2_{n-3 DPA}, an endogenously formed mediator biosynthesized from the omega-3 fatty acid n-3 docosapentaenoic acid. The key steps are the Midland Alpine borane reduction, Sonogashira cross-coupling reactions, and a Z-selective alkyne reduction protocol, yielding RvD2_{n-3 DPA} methyl ester in 13 % yield over 12 steps (longest linear sequence). The physical property data (UV chromophore, chromatography and MS/MS fragmentation) of the synthetic lipid mediator matched those obtained from biologically produced material. Moreover, synthetic RvD2_{n-3 DPA} also carried the potent biological activities of enhancing macrophage uptake of Staphylococcus aureus and zymosan A bioparticles.     

热带观赏鱼虎头鲨细菌性败血病的诊断与治疗

阐述了热带观赏鱼虎头鲨细菌性败血病的诊断与治疗,通过治疗试验,说明由复方磺胺甲噁唑、甲氧苄胺嘧啶两种药物组合治疗的治愈效果最佳。     

Aerogels from Unaltered Bacterial Cellulose: Application of scCO2 Drying for the Preparation of Shaped,Ultra‐Lightweight Cellulosic Aerogels

Bacterial cellulose produced by the gram‐negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra‐lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 °C and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg · cm^?3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open‐porous network structure that consists of a comparatively high percentage of large mesopores and smaller macropores.

     

细菌纤维素增强环氧树脂透明复合材料的制备与性能

通过2种不同细菌纤维素添加方式,采用模压成型的方法制备细菌纤维素／环氧树脂（BC／EP）透明复合材料,研究了复合材料的微观形态、力学性能、动态热机械性能以及透明性能．结果表明：对于BC添加方式I制得的样品,BC可以同时增强增韧EP,随着BC含量增加,复合材料的拉伸强度和断裂伸长率逐渐增大,与纯EP相比,BC质量分数为55％的复合材料的拉伸强度和断裂伸长率分别提高4倍和11倍;对于BC添加方式Ⅱ制得的样品,BC的高强度高弹性模量及其与EP界面强烈相互作用,提高了BC／EP复合材料的弹性模量,BC的网络结构阻碍了EP的固化交联,从而降低其交联密度,使得EP玻璃化转变温度降低;BC／EP复合材料的断面显示纤维状的韧性断裂特征,表面显示均匀分布且面内取向的BC纳米网络结构,因而复合材料的力学性能显著提高;BC干膜透明性较差,BC／EP复合材料的透明性比BC干膜显著提高．