Synthesis,characterization and in vitro antimicrobial activity of some novel 5-substituted Schiff and Mannich base of isatin derivatives

With the aim of developing potential antimicrobials, a series of novel Ciprofloxacin methylene isatin derivatives incorporating different aromatic aldehydes were synthesized and characterized by FTIR, ¹H NMR, Mass spectroscopy and bases of elemental analysis. In addition, the in vitro antibacterial and antifungal properties were tested against some human pathogenic microorganisms by employing the disc diffusion technique. A majority of compounds were showing activity against several of the microorganisms. The relationship between the functional group variation and the biological activity of the evaluated compounds is discussed. From comparisons of the compounds, 3c was determined to be the most active compound.     

核酸碱基的非谐性振动:正规及错配碱基对的一维和二维红外光谱及其结构基础

用量子化学计算研究了正规Watson-Crick碱基对和四例典型的错配碱基对.对碱基单体和二聚体进行了详细的非谐性频率分析,以揭示其结构方面的一些振动特征.研究发现这些振动特征能在模拟的一维和二维红外光谱中很好地表现出来.利用势能分布研究了所选简正模式的离域化程度,发现从孤立的碱基单体到参与氢键的二聚体,模式的离域化程度变化很大;同时,这些模式的非谐性常数也发生了相应的改变.以人们通常认为的位于红外光谱中6-μm波长区域的羰基伸缩模式为例进行了探讨.     

含硫Schiff碱的合成及其抑菌活性

1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮分别与氨基硫脲、肼基二硫代甲酸苄酯、肼基二硫代甲酸甲酯和1,3-二氨基硫脲反应合成了6个含硫Schiff碱(6a~6 e),其结构经UV,1H NMR,IR和元素分析表征。初步生物活性测试结果表明,部分6对大肠杆菌和枯草芽孢杆菌具有一定的抑菌活性。     

铽(Ⅲ)的邻香兰素二胺类双希夫碱配合物的合成和表征

本文首次合成了邻香兰素(2-羟基-3-甲氧基苯甲醛)与乙二胺、联苯胺、对苯二胺缩合而成的双希夫碱(分别以L~1、L~2、L~3表示)的铽(Ⅲ)配合物。用元素分析、红外光谱、摩尔电导、X-射线粉末衍射物相分析、X-射线光电子能谱、差热及热重分析近代物理化学测试手段,确定了这些配合物的组成和键合情况,并对其结构和某些物理化学性质进行了研究。     

含二茂铁基希夫碱及其配合物的研究

本文报道了含二茂铁基希夫碱-1,2-亚乙基双(二茂铁甲酰基异丙亚胺)及其某些d,f过渡金属配合物的合成,并对其结构进行了表征。     

Synthesis of WO2pyprMCM-41 as selective and reusable catalyst for the epoxidation of alkenes

The sythesis, characterization and catalytic activity of WO₂pypr [N,N′-bis (2-pyrrolmethlidenaminopropyl) amine] complexed to MCM-41 surface in the epoxidation of some alkenes with excellent selectivity toward the corresponding epoxides is described in this presentation.     

邻香兰素缩邻氨基苯甲酸与稀土硝酸盐配合物的合成与表征

邻香兰素缩邻氨基苯甲酸与稀土硝酸盐配合物的合成与表征范玉华毕彩丰赵淑英（山东建材学院应用化学系济南２５００２２）程桂英（山东省化工学院济南２５００００）关键词稀土硝酸盐希夫碱配合物中图分类号Ｏ６４１．４某些水杨醛类氨基酸的金属配合物具有显著的生物活性...     

双环[2，2，1]庚-5-烯-2-甲酰基芳香醛腙的合成和生物活性

合成了七个未见文献报道的双环[2，2，1]庚-5-烯-2-甲酰基芳香醛腙席夫碱 类化合物。用核磁共振氢谱、红外光谱和元素分析对新化合物进行了表征，考察了 它们的生物活性。结果表明某些化合物具有除草作用、抗菌作用和植物生长调节作 用。     

席夫碱及其金属配合物的合成及生物活性研究进展

席夫碱及其金属配合物具有独特的抗菌、抗肿瘤和抗氧化等生物活性.为筛选高效低毒的药物,人们合成了大量不同类型的席夫碱及其金属配合物并对其生物活性进行了研究.本文综述了近年来席夫碱及其金属配合物的合成,以及在抗菌、抗氧化、抗肿瘤等方面生物活性的研究进展,并为进一步研究其在医药领域的应用提供了信息支持.     

Synthesis,Characterization and Antimicrobial Activity of a New Aromatic Sulfonyl Hydrazone Derivative and Its Transition Metal Complexes

In this study, benzenesulfonicacid‐1‐methylhydrazide (bsmh) derivatives such as 2‐hydroxy‐1‐naphtaldehydebenzenesulfonylhydrazone (Hnafbsmh) and its Ni(II), Pd(II), Pt(II), Cu(II), Co(II) complexes were synthesized. The structures of these complexes were investigated using elemental analyses (FT‐IR, LC‐MS, UV‐VIS), magnetic susceptibility and conductivity measurement techniques. The complexes were found to have general compositions [ML₂]. All the synthesized complexes were evaluated in vitro as antimicrobial agents against representative strains of six gram‐positive and four gram‐negative bacteria and as an antifungal agent by disc diffusion methods. All the bacteria and fungi studied were screened against some commercial antibiotics to compare them with our chemical's zone diameters.     

壳聚糖亚胺环钯化合物对碘代苯与丙烯酸反应的催化性能

以苯甲醛或其衍生物对壳聚糖进行接枝改性制得了壳聚糖席夫碱配体,再与Li2PdCl4进行环钯化合成了壳聚糖亚胺环钯化合物催化剂1-10.研究了该类催化剂对碘代苯或碘苯衍生物与丙烯酸偶联反应的催化性能,结果表明该类催化剂具有较好的催化活性和一定的重复使用性能.     

[α-(2-氧代烷基)-α-(取代苯胺基)甲基苯基]-β-D-吡喃阿洛糖苷的合成及镇静活性研究

以豆腐果苷为原料, 通过Mannich反应与取代苯胺和脂肪酮共合成了七个豆腐果苷衍生物, 均未见文献报道. 其结构经¹H NMR, IR, MS和HRMS确认, 并进行了药理活性筛选. 结果表明, 部分化合物均具有良好的镇静活性. 其中, 化合物2a (200 mg/kg), 2b (200 or 100 mg/kg)和2e (200 mg/kg)与豆腐果苷相比较, 具有更强的疗效.     

α-(5—四唑基)氨基烃基膦酸酯的合成及其生物活性

合成了12个新的5—氨基—1H—1，2，3，4—四唑的Schiff碱，而后与亚磷酸 二乙酯反应，合成出了12个新的含四唑基的α-氨基烃基膦酸酯，通过IR，^1H NMR，^31P NMR和元素分析证实了它们的结构．生物活性实验证明，一些目标化合 物具有良好的植物生长调节活性，其中氯代苯甲醛和吲哚甲醛的Schiff碱生成的α -氨基烃基膦酸酯的生长素活性更好。     

含氨基酸席夫碱的5-氟尿嘧啶衍生物的合成及其抗肿瘤活性

以N 1-(2-四氢呋喃烷基)-5-氟尿嘧啶为原料, 与1,4-二溴丁烷反应, 得到N¹-(2-四氢呋喃烷基)-N³-(4-溴丁基)-5-氟尿嘧啶(2), 最后与氨基酸席夫碱的钾盐缩合, 得到13个新的目标化合物3. 其结构经IR, ¹H NMR, MS和元素分析确证. 初步的体外抗肿瘤试验结果表明, 目标化合物具有一定的抗肿瘤活性.     

银基微电极方波伏安法测定矿样中痕量铅镉

研究了银基质微电极的伏安特性，经与玻碳电极比较，具有灵敏度高、重现性好、分辨率强、线性范围宽、使用寿命长等优点。并克服了宏观电极的某些缺点，消除了充电电流的影响，基线平稳，峰形清晰。     

Supramolecular interactions in some organic hydrated 2,4,6-triaminopyrimidinium carboxylate and sulfate salts

Four salts, namely, 2,4,6-triaminopyrimidinium 6-chloronicotinate dihydrate, C₄H₈N₅⁺·C₆H₃ClNO₂⁻·2H₂O, (I), 2,4,6-triaminopyrimidinediium pyridine-2,6-dicarboxylate dihydrate, C₄H₉N₅²⁺·C₇H₃NO₄²⁻·2H₂O, (II), 2,4,6-triaminopyrimidinediium sulfate monohydrate, C₄H₉N₅²⁺·SO₄²⁻·H₂O, (III), and 2,4,6-triaminopyrimidinium 3,5-dinitrobenzoate dihydrate, C₄H₈N₅⁺·C₇H₃N₂O₆⁻·2H₂O, (IV), were synthesized and characterized by X-ray diffraction techniques. Proton transfer from the corresponding acid to the pyrimidine base has occurred in all four crystal structures. Of the four salts, two [(I) and (IV)] exist as monoprotonated bases and two [(II) and (III)] exist as diprotonated bases. In all four crystal structures, the acid interacts with the pyrimidine base through N—H…O hydrogen bonds, generating an R₂²(8) ring motif. The sulfate group mimics the role of the carboxylate anions. The water molecules present in compounds (I)–(IV) form water-mediated large ring motifs. The formation of water-mediated interactions in these crystal structures can be used as a model in the study of the hydration of nucleobases. Water molecules play an important role in building supramolecular structures. In addition to these strong hydrogen-bonding interactions, some of the crystal structures are further enriched by aromatic π–π stacking interactions [(I) and (II)].     

In vitro antimicrobial and antioxidant evaluation of rare earth metal Schiff base complexes derived from threonine

Six novel Ln(III) Schiff base complexes were synthesized using rare earth metals with threonine and 5‐bromosalicylaldehyde, namely Pr(III), Sm(III), Gd(III), Tb(III), Er(III) and Yb(III) Schiff bases. These complexes were characterized using elemental analysis, molar conductivity, Fourier transform infrared and UV–visible spectroscopies, and thermogravimetry–differential thermal analysis. The general formula of the complexes is [Ln(L)(NO₃)₂(H₂O)].NO₃ (L = Schiff base ligand). The spectroscopic data reveal that the Schiff base ligand behaves as a tridentate ligand with ONO donor atoms sequencing towards the central metal ion. An investigation of fluorescence properties of the Sm(III), Er(III) and Tb(III) complexes shows that the Ln(III) ions can be sensitized efficiently by the ligand to some extent. Antimicrobial activity testing indicates that all six complexes exhibit antibacterial and antifungal ability against microbes with broad antimicrobial spectra. In addition, the antioxidant properties of the complexes were also screened. Copyright © 2014 John Wiley & Sons, Ltd.     

Biaryl-bridged Schiff base complexes of zirconium alkyls: synthesis structure and stability

Three substituted salicylaldimine derivatives H₂L^1-3 of 2,2′-diamino-6,6′-dimethylbiphenyl give, under appropriate conditions, isolable alkyls of zirconium [ZrL^1-3R₂] (R=CH₂Ph, CH₂Bu^t). Two molecular structures confirm their cis-α geometry (C₂-symmetric with cis alkyl ligands). They decompose via 1,2-migratory insertion of an alkyl group to imine, followed in some instances by a second similar reaction. The dimeric molecular structure of one such doubly-inserted product is presented. The kinetics of decomposition by this process are studied briefly, and it is noted that the rate increases with increased steric demand of the salicylaldimine unit.     

Spectrophotometric and spectrofluorimetric studies of novel heterocyclic Schiff base dyes

Novel heterocyclic Schiff base dyes were prepared by the reaction of salicylaldehyde/2-Hydroxy-1-naphthaldehyde with different heterocyclic amines. Results of the newly synthesized compounds established by FT-IR, ¹H-NMR, ¹³C-NMR and GC–MS spectroscopic experiments were consistent with their chemical structures. Resulted heterocyclic Schiff base dyes were found to be pure from data obtained by the elemental analysis. In addition, spectrophotometric and spectrofluorimetric studies showed that these dyes were good absorbent and fluorescent. Fluorescence polarity study data revealed that some of these compounds were sensitive to the polarity of the microenvironment provided by different solvents. Time-based fluorescence steady-state measurements also showed that these heterocyclic Schiff base dyes have high photostability against photobleaching.     

Discovery of novel double pyrazole Schiff base derivatives as anti-tobacco mosaic virus (TMV) agents

Many pyrazole derivatives were reported to exhibit highly activity towards tobacco mosaic virus (TMV). In this work, an optimized pyrazole Schiff base scaffold was designed and introduced to derive novel potential TMV inhibitors. Thirty-six compounds were synthesized, characterized by elemental analysis, mass spectra and nuclear magnetic resonance (NMR) spectroscopy and evaluated by biological experiments. The bioassay results showed that some of the synthesized compounds exhibited excellent anti-TMV activities. Especially, 5-chloro-3-methyl-1H-pyrazole contained compound 4j showed ningnanmycin comparable inhibitory activity and can be considered as potential anti-TMV candidate agent. With molecular docking, compound 4j insert into nucleotide sequence (GAAGUU) of OriRNA stably which revealed nucleotide could be a target of these compounds.