共查询到20条相似文献,搜索用时 62 毫秒
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通过2-氨基吡啶与β环糊精醛3在甲醇水溶液中反应合成了一种新型含吡啶基β-环糊精衍生物4,并采用荧光光谱滴定法测定了它与几种脂肪氨基酸在磷酸盐缓冲溶液(pH= 7.2, 0. 1mol· L-1)中于 25℃时形成超分子配合物的稳定常数.化学计量法结果显示,化合物4与氨基酸形成了1:1的超分子配合物.圆二色谱研究表明,在溶液中化合物4的取代基浅包结进入自身环糊精空腔.修饰环糊精中的吡啶基作为一种光谱探针,不仅可以识别氨基酸分子的尺寸或形状,而且还可以识别L/D-型手性对映体之间的差异.与单-[6-(1-吡啶基)-6-脱氧]-β-环糊精5相比,化合物4对氨基酸的对映体选择性发生翻转,其中对D/L-丝氨酸给出最高的对映体选择性达5.4.从主-客体间几何互补、诱导楔合以及几种弱相互作用力的协同效应,讨论了环糊精衍生物选择性结合氨基酸形成超分子配合物的稳定性. 相似文献
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毛细管电动色谱带电环糊精拆分N—FMOC氨基酸对映体 总被引:3,自引:0,他引:3
将负电性磺丁基-β-环糊精手性添加剂应用于毛细管电泳氨基酸对映体的拆分研究中,对8种氨基酸对映体与9-芴甲基氧基甲酰氯(FMOC-Cl)生成的衍生物进行了分离,其中5种得到了基线分离。考察了背景电解质pH值及磺丁基-β-环糊精的浓度对N-FMOC氨基酸对映体拆分的影响。 相似文献
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交联壳聚糖树脂的活化及其对β—环糊精的固载化研究 总被引:9,自引:1,他引:8
天然碱性多糖-壳聚糖用戊二醛交联成球,通过环氧氯炳烷活化后与β-环糊精反应,得到交联壳聚糖固载化的β-环糊精,研究了活化过程及固载化条件对β-环糊精固载量的央环氧氯炳烷浓度为30%(v/v)时最佳活化条件为:40℃、3h、0.4mol/LNaOH及三甲基亚砚(DMSO)含量50%(v/v);而在β-环糊精:树脂=1:1(w/w)时,最佳固载化条件为:4h、0.1mol/L NaOH、60℃。 相似文献
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盐酸美西律对映体的毛细管电泳分离 总被引:4,自引:0,他引:4
以β-环糊精的两种生物做为毛细管电泳手性分离添加剂,对盐酸美西律的对映体进行了拆分研究。其中,2,6-O-二甲基β-环糊精可将对映体部分拆分,而2,3,6-O-三甲基β-环糊精时,可基线分离对映体。研究了两种甲基化β-环糊精的浓度及工作电压对分离的影响。 相似文献
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环糊精流动相添加剂分离色氨酸对映体的薄层色谱法 总被引:3,自引:0,他引:3
用β环糊精(β-CD)作为流动相手性添加剂,在聚酰胺薄膜上分离2,4二硝基苯基色氨酸(DNP-Trp)对映体,流动相最佳组成:βCD尿素饱和溶液-甲醇甲酸(9:1:2,V/V/V),还分离了非对映异构体辛可宁和辛可尼丁以及邻、间、对硝基苯胺。 相似文献
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A fast, sensitive and reliable potentiometric stripping analysis (PSA) is described for the selective detection of the marine pathogenic sulfate-reducing bacterium (SRB), Desulforibrio caledoiensis. The chemical and electrochemical parameters that exert influence on the deposition and stripping of lead ion, such as deposition potential, deposition time and pH value were carefully studied. The concentration of SRB was determined in acetate buffer solution (pH 5.2) under the optimized condition (deposition potential of −1.3 V, deposition time of 250 s, ionic strength of 0.2 mol L−1 and oxidant mercury (II) concentration of 40 mg L−1). A linear relationship between the stripping response and the logarithm of the bacterial concentration was observed in the range of 2.3 × 10 to 2.3 × 107 cfu mL−1. In addition, the potentiometric stripping technique gave a distinct response to the SRB, but had no obvious response to Escherichia coli. The measurement system has a potential for further applications and provides a facile and sample method for detection of pathogenic bacteria. 相似文献
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Levan is fructose polymer as the result of biosynthesis by levansucrase. This study is aimed to explore the potential of moderate halophilic bacteria Bacillus licheniformis BK AG21 isolated from Bledug Kuwu, Purwodadi Central Java, in producing levan. This bacteria displayed positive potential in producing levan based on the appearance of slime mucoid on a sucrose medium. The optimum production of levan was attained when the culture medium containing sucrose and peptone as respective carbon and nitrogen sources was shaking incubated with speed of 150 rpm for 24 hours at 37 oC. Thermal gravimetric analysis revealed that levan produced by B. licheniformis BK AG21 decomposed at 214 oC. The structure of the isolated levan was elucidated with FTIR, 1H and 13C NMR spectroscopies. Based on the obtained spectroscopic data, the isolated levan was composed of β-(2,6)-linkages of fructose residues. 相似文献
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A novel series of quaternary ammonium cationic derivatives based on tetrapyridyl-porphyrin was synthesized.All the compounds were evaluated for their in vitro antibacterial activities against S.aureus,E.coli and P.aeruginosa,and antifungal activities against C.albicans,where microorganisms were exposed and unexposed to the irradiation.The results revealed that some of these compounds,especially,3a and 4a displayed satisfactory antibacterial activity against Gram-positive bacteria S.aureus and moderate an... 相似文献
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Isolation of L. casei 925 a.k. Culture - Medium Components Bacteriocinogenic for Helicobacter pylori
A search was made for bacterial antagonists against the gastroduodenal pathogenH. pylori.Protein fractions active against the pathogen were isolated from culture medium of lactobacterium. 相似文献
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Dr. Pradipta Behera Dr. Krishna Kumar Singh Prof. Deepak Kumar Saini Prof. Mrinmoy De 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(47):e202201386
The precise discrimination of microbes based on family, class and drug resistivity is essential for the early diagnosis of infectious diseases. Information about the type and strength of drug resistivity can help the analyst to prescribe a suitable antibiotic at the proper dosage to completely eradicate microbes without giving them a chance to gain further resistance. Herein, we propose a sensor array based on the use of cationic two-dimensional MoS2 units and green fluorescence protein as building blocks. Cationic surfaces of receptors with various functionality were suitable for tunable interaction with anionic surfaces of microbes. The array successfully discriminates six different bacterial strains. The versatile ability of the receptors to bind with the wild-type as well as the corresponding ampicillin-resistant strain contributed significantly to rapid detection with high sensitivity. The optimized array was able to classify five different types and three different extents of drug-resistant variants of Escherichia coli by using bacteria cells and lysates. Finally, we have introduced the cross identification method using both bacteria cells and lysates and we found a great enhancement of detection in sensitivity and accuracy. This is the first report of this approach, which can be extended to many other methods for better accuracy in array-based detection. 相似文献
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