Facile solid phase synthesis of N-cycloguanidinyl-formyl peptides

A novel strategy of solid phase synthesis of N-cycloguanidinyl-formyl peptides has been established and investigated which involved coupling orthogonal protected diaminoacid with resin bound peptide, α-amino group deprotection, guanidinylation of α-amino group by bis-Cbz-1H-pyrazole-1-carboxamidine followed by cleavage and cyclization in solution, and finally removing Cbz by palladium catalyzed hydrogenation. Through this method, cycloguanidine could be introduced to either N-terminus or sidechain of designated peptides. The reaction conditions were facile, straightforward, and totally adaptive to common solid phase peptide synthesis strategy.     

Two novel polycyclic spiro lignans from Gymnotheca involucrata

Two novel lignans, gymnothespirolignans A (1) and B (2), possessing a rare polycyclic spiro skeleton, were isolated from the endemic plant of Gymnotheca involucrata Pei. Their structures were determined by spectroscopic evidences and the absolute configurations were confirmed by single crystal X-ray diffraction analysis. Compounds 1 and 2 showed promising antiviral activities against RSV with an IC₅₀ value of 31.87 and 17.51 μM, respectively.     

Electrophile-driven copper-catalyzed one-pot synthesis of 3-halogen quinoline derivatives

A convenient and regioselective one-pot synthesis of 3-chloride or 3-bromide quinoline derivatives was achieved through a Grignard addition reaction by alkynyl Grignard regent to o-trifluoroacetyl aniline and a Cu(II)-catalyzed cyclization–halogenation tandem reaction with aqueous HCl or HBr as electrophilic reagent.     

Study of Interactions and Association Thermodynamics Between Sudan Red and Sodium Dodecyl Sulfate in Microemulsions

The absorption spectrum of Sudan red III (SR) in oil solutions and a series of O/W microemulsion with surfactant sodium dodecyl sulfate (SDS) has been determined by the UV-Vis spectrophotometer. We found that an association interaction existed between the stain SR and anionic surfactant SDS in water/mixed oil/SDS microemulsions. By measuring the absorbance of Sudan red in a series of microemulsions which has different R values and using the appropriate association models to analyze the experimental data, we obtain the association constants of SR and SDS, and the values of thermodynamics functions of associationΔ_r G _m has also been calculated from the association constants.     

Solvent extraction of uranium from aqueous solutions by α-benzoinoxime

Solvent extraction of uranium with α-benzoinoxime from aqueous solutions has been systematically investigated. The extraction equilibration was very fast and achieved at 60 s for uranium. The extraction of uranium was pH-dependent using α-benzoinoxime as extractant. The effect concentration of uranium and α-benzoinoxime was studied. The uranium loaded in the organic phase can be stripped efficiently with 93 % yield using 0.1 M HCl as the stripping agent in a single stripping step. A good selectivity for uranium was observed through α-benzoinoxime as extractant from aqueous solution with other interfering cation ions. Present study suggested that α-benzoinoxime can be used as a potential extractant for separation of uranium from aqueous solution using centrifugal extractor in industrial application.     

Adsorption of uranium ions from aqueous solution by amine-group functionalized magnetic Fe3O4 nanoparticle

The magnetic Fe₃O₄ nanoparticle was functionalized by covalently grafting amine group with (3-aminopropyl) trimethoxy silane, and the Fe₃O₄–NH₂ nanoparticle and the Fe₃O₄ nanoparticle were characterized by Fourier transform infrared, and X-ray diffraction. And the results indicated the amine-group was immobilized successfully on the surface of Fe₃O₄. The adsorption behavior of uranium from aqueous solution by the Fe₃O₄ nanoparticle and the Fe₃O₄–NH₂ nanoparticle was investigated using batch experiments. The pH of initial aqueous solution at 5.0 and 6.0 were in favour of adsorption of uranium, and the adsorption percentage of uranium by the Fe₃O₄ nanoparticle and the Fe₃O₄–NH₂ nanoparticle were 81.2 and 95.6 %, respectively. In addition, the adsorption of uranium ions could be well-described by the Langmuir, Freundlich isotherms and pseudo-second kinetic models. The monolayer adsorption maximum capacity of the Fe₃O₄ nanoparticle and the Fe₃O₄–NH₂ nanoparticle were 85.35 and 268.49 mg/g at 298.15 K, respectively, which indicate the adsorption capacity the Fe₃O₄ nanoparticle was improved by amine functionalization.     

囊泡状二氧化硅的合成及油气吸附性能

以正硅酸四甲酯(TMOS)为硅源,P123(EO20PO70EO20)为表面活性剂,在p H=6的磷酸缓冲体系中制备了囊泡状二氧化硅材料.利用乙醇萃取脱除模板剂P123,电镜观测结果表明所得二氧化硅具有大孔囊泡结构,N2吸附结果表明其具有高比表面积和大孔容.通过Boehm滴定法确定了硅羟基数量与吸水率呈正相关.用囊泡状二氧化硅材料与商业化活性炭(AC)和硅胶(SG)对水蒸气、正己烷和油气进行静态吸附.在自建的动态正己烷吸附装置上用对囊泡状二氧化硅材料和商业化AC和SG对正己烷进行动态吸附.吸附结果表明,囊泡状二氧化硅材料的静/动态吸附容量和稳定性都远高于商业化活性炭和硅胶.     

生物燃料电池处理生活污水同步产电特性研究

以某生活污水处理厂缺氧池活性污泥为接种体,以葡萄糖为模拟生活废水,构建双室型微生物燃料电池。利用微生物燃料电池(MFC,Microbial fuel cell)实现生活废水降解与同步产电。研究基质降解动力学及温度对MFC电极过程动力学的影响,明确微生物电化学活性、阳极传荷阻抗、阳极电势、电池产能之间的关系,考察库伦效率及COD去除率。研究结果表明,电池功率输出与基质浓度关系遵循莫顿动力学方程:P=Pmaxc/(ks+c),其中,半饱和常数ks为138.5 mg/L,最大功率密度Pmax为320.2 mW/m2。葡萄糖浓度较小时,反应遵循一级动力学规律:-dcA/dt=kcA,k=0.262 h-1。操作温度从20℃提高到35℃,生物膜电化学活性不断提高,传荷阻抗从361.2Ω减小到36.2Ω,阳极电极电势不断降低,同时,峰值功率密度从80.6 mW/m2提高到183.3 mW/m2。45℃时,产电菌活性降低,峰值功率密度减小到36.8 mW/m2。葡萄糖浓度为1 500 mg/L,温度为35℃时,MFC电化学性能最佳,稳定运行6 h后库伦效率为44.6%,COD去除率为49.2%。     

新型吡唑联吡咯类杂环化合物的合成及杀菌活性

为寻找具有更高生物活性、更环保的新农药杀菌剂,基于杀菌剂氟咯菌腈设计并合成了10个新型吡唑联吡咯类杂环化合物,以吡唑环代替氟咯菌腈上原有的苯环,以期提高其杀菌活性.采用1H NMR,FTIR,单晶X射线衍射、元素分析和熔点测定等测试手段对目标化合物及其中间体的结构进行了表征与确认,并通过挥发法培养得到了6个目标化合物的单晶.还对其中6个化合物进行了生物活性测试,测试结果表明各化合物对水稻纹枯病、黄瓜灰霉病、黄瓜霜霉病均表现出一定的抑菌效果,可作为先导化合物对其结构进行深入的研究,为新农药杀菌剂的开发提供了理论支持.     

Hydrothermal preparation of hybrid carbon/silica monolithic capillary column for liquid chromatography

A simple, easy and economical approach for the preparation of a hybrid carbon/silica monolithic capillary column was described for the first time by using silica monolith as framework in combination with hydrothermal carbonization at 180°C. During the preparation process, formamide was introduced to the reaction solutions to reduce the dissolution rate of monolithic silica skeleton and its optimal concentration was 1.5 M. Fourier transform infrared spectrometry, scanning electron microscopy, energy dispersive X‐ray spectrometry, and inverse size exclusion chromatography were carried out to characterize the as‐prepared column. The results demonstrated that carbon spheres ranging from 150 to 1000 nm were successfully attached to the surface of silica skeleton. The prepared hybrid carbon/silica column had a permeability of 4.4 × 10^?14 m². Chromatographic performance of the column was evaluated by separation of various compounds including alkylbenzenes, nucleosides and bases, and aromatic acids. The column exhibited an efficiency of 75 000 plates/m for butylbenzene at the optimal linear velocity of 0.23 mm/s. The successful separation of these compounds and the study on mechanism indicated that the column can be applied in mixed‐mode chromatography.