苯丙醇胺对映体的毛细管电泳分离和定量

采用环糊精及其衍生物作为手性选择对苯丙醇胺对映体进行了分离,研究了环糊精种类和浓度对分离的影响。结果表明,采用２,６－０－二甲基－β－环糊精（ＤＭ－β－ＣＤ）可以使苯丙醇胺对映体达到基线分离。在选定的条件下,考察了苯丙醇 的定量线性范围、检测限和重现性,测得苯丙醇胺的线性范围为２０～２００ｍｇ／Ｌ,检测限为１ｍｇ／Ｌ迁移时间重现性的ＲＳＤ为１．０％,峰面积重现性的ＲＳＤ小于３．５％,并对康泰克实样     

手性气相色谱分离α-醇腈和α-羟基酸对映体

以３－丙酰基－２,６－Ｏ－二戊基－γ－环糊精和３－三氟乙酰基－２,６－Ｏ－二戊基－γ－环糊精为手性固定相,利用气相色谱进行了α－醇腈化合物、α羟基酸以及二共存时的对映体分离。系统观察了影响对映体分离的主要因素,优化了十种α－醇腈和七种α－羟基酸拆分条件,３－三氟乙酰基－２,６－Ｏ－二戊基－γ－环糊精毛细管柱的分离因子达到１．０５～３．１２,对α－羟基酸,并对分离的机理进行了初步分析。     

除虫剂二氯菊酸甲酯的手性分离

在全甲基－β－环糊精（ＰＭＢＣＤ）,２,６－０－二丁基－３－０－丁酰基－β－环糊精（ＤＢＢＣＤ）,２,６－０－二壬基－３－０－三氟乙酰基－β－环糊精（ＤＮＢＣＤ）及混合固定相（ＰＭＢＣＤ＋ＤＢＢＣＤ）等５种手怀固定相上分离了除虫剂二氯菊酸甲酯（ＰＴ）的对映异构体,并测定了部分热力学数据。发现ＤＰＡＢＣＤ对ＰＩ的分离效果最好,且不同固定相对ＰＩ具有相同或相似分机理。     

超分子体系中的分子识别研究──XXXV.含吡啶基β-环糊精衍生物的合成及其对氨基酸分子的手性识别

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．     

高效液相色谱手性流动相添加剂分离肾上腺素类对映体

将β－环糊精、２,６－二甲基－β－环糊精、２,３,６－三甲基－β－环糊精分别作为手性流动相添加剂,较系统地研究了Ｄ,Ｌ－肾上腺素、Ｄ,Ｌ－异丙肾上腺素、Ｄ,Ｌ－麻黄碱在反相ＨＰＬＣ系统中的拆分,建立了甲基化β－环糊精动态手性固定相法分离肾上腺素类药物对映体的方法,探讨了立体选择性与环糊精主体和客体分子结构之间的关系     

毛细管电动色谱带电环糊精拆分N—FMOC氨基酸对映体

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。     

交联壳聚糖树脂的活化及其对β—环糊精的固载化研究

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℃。     

盐酸美西律对映体的毛细管电泳分离

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。     

不同稀释剂对改性环糊精手性分离的影响

用α－苯乙胺、反式－二氯菊酸甲酯做手性试剂,考察了５种稀释剂稀释２,６－二－Ｏ－Ｔ基－３－Ｏ＝丁酰基－β－环糊精的对映体拆分效果。结果表明,用ＳＰ－７９做知释剂与ＯＶ－７、ＯＶ－１７０１、ＳＥ－５４、ＰＥＧ－２０Ｍ等相比,前者有基本相同的柱效、略高或基本一致的对映体选择性。通过焓熵关系分析发现,选用所述不同稀释剂不改变手性拆分机制。     

环糊精流动相添加剂分离色氨酸对映体的薄层色谱法

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。     

微生物燃料电池电能原位利用及其衍生形式的研究进展

作为一种生物催化的电化学系统,微生物燃料电池(MFC)目前研究多集中于提高产电能力和污水处理能力。将MFC产生的电能进行原位利用,可以有效对废水进行处理和修复。为了更有效地原位利用MFC产生的电能并修复污染水体,本文介绍了一种电能原位利用的新形式—微生物电化学呼吸器(MES)并综述了其的研究进展。MES作为一种短路的新型MFC,将产生的电能进行原位利用,可以提高废水的优化处理效率。作为一种新型污水处理装置,MES在环保领域将会拥有广阔的应用前景。     

抗菌处理含铜铁素体不锈钢的耐微生物腐蚀性能

采用电化学测试技术及微生物学方法, 研究了抗菌处理含铜铁素体不锈钢在含有培养基的异养菌溶液中的耐蚀性能. 结果表明, 不锈钢的腐蚀电位随异养菌的新陈代谢呈现规律性变化, 抗菌处理使不锈钢在菌液中钝化膜的稳定性得到改善, 点蚀敏感性降低; 抗菌不锈钢表面弥散分布的ε-Cu析出相的杀菌作用, 降低了异养菌的活性, 减缓了异养菌对抗菌不锈钢的腐蚀, 提高了抗菌不锈钢耐微生物腐蚀性能.     

电化学活性微生物在微生物燃料电池阳极中的应用

微生物燃料电池是一种利用电化学活性微生物催化降解有机物的同时产生电能的新型产能装置。阳极电化学活性微生物特征及催化活性是影响微生物燃料电池产电效率的关键因素之一。本文对应用于阳极上的电化学活性微生物的富集、来源、菌种的生理生化特征及产电能力等进行了综述。     

Selective and specific detection of sulfate-reducing bacteria using potentiometric stripping analysis

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.     

Isolation and Characterization of Levan from Moderate Halophilic Bacteria Bacillus licheniformis BK AG21

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.     

Study on the synthesis and antimicrobial activity of novel cationic porphyrins

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...     

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.     

1-取代芳基-4-乙氧羰基-5-二甲氨基亚甲基氨基-1,2,3-三唑衍生物的新法合成

以1-取代芳基-4-乙氧羰基-5-氨基-1,2,3-三唑衍生物为原料,用简单有效的方法在非常温和的条件下以较好的收率合成了一系列新型的1-取代芳基-4-乙氧羰基-5-二甲氨基亚甲基氨基-1,2,3-三唑及其衍生物,所得化合物未见文献报道.新化合物的结构用红外光谱、核磁共振、质谱和元素分析确证,同时初步研究了这些化合物的抑菌性能.     

Rapid Discrimination of Bacterial Drug Resistivity by Array-Based Cross-Validation Using 2D MoS2

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.