One-pot synthesis of functionalized furamide derivatives via a three-component reaction between an amine, diketene and dibenzoylacetylene in the presence of triphenylphosphine

An effective route to functionalized furamide derivatives is described. This involves reaction of N-alkyl-3-oxobutanamides, derived from the addition of amines to the diketene, and dibenzoylacetylene in the presence of triphenylphosphoine. The reactive 1:1 intermediate obtained from the addition of triphenylphosphine to dibenzoylacetylene was trapped by OH-acids such as N-alkyl-3-oxobutanamide to produce functionalized furamide derivatives.     

Synthesis,characterization, cytotoxic activity and DNA-binding studies of cobalt (II) mixed-ligand complex containing pyridine-2,6-dicarboxylate ion and 2-aminopyrimidine

Treatment of pyridine-2,6-dicarboxylic acid and 2-aminopyrimidine with Co(NO₃)₂?6H₂O under hydrothermal conditions led to a new Co (II) complex [Co(amp)(pydc)(H₂O)₂]?H₂O (1), which was characterized by infrared spectroscopy, elemental analysis as well as X-ray diffraction studies. The DNA-binding behavior of the complex has been studied by UV–Vis absorption and fluorescence spectroscopic titration, viscosity measurements, thermal denaturation and circular dichroism (CD). The experimental results indicated that Co (II) complex was bound to DNA by an intercalative mode. The intrinsic binding constant of Co (II) complex with DNA was (3.80 ± 0.02) × 10⁴ M^?1. The biological effects of the Co (II) complex were also studied by MTT assay in MCF-7 and HT-29 cancer cell lines. Treatment of MCF-7 and HT-29 cells with Co (II) complex resulted in a concentration-dependent cell growth inhibition.     

Using synchrotron radiation inline phase‐contrast imaging computed tomography to visualize three‐dimensional printed hybrid constructs for cartilage tissue engineering

Synchrotron radiation inline phase‐contrast imaging combined with computed tomography (SR‐inline‐PCI‐CT) offers great potential for non‐invasive characterization and three‐dimensional visualization of fine features in weakly absorbing materials and tissues. For cartilage tissue engineering, the biomaterials and any associated cartilage extracellular matrix (ECM) that is secreted over time are difficult to image using conventional absorption‐based imaging techniques. For example, three‐dimensional printed polycaprolactone (PCL)/alginate/cell hybrid constructs have low, but different, refractive indices and thicknesses. This paper presents a study on the optimization and utilization of inline‐PCI‐CT for visualizing the components of three‐dimensional printed PCL/alginate/cell hybrid constructs for cartilage tissue engineering. First, histological analysis using Alcian blue staining and immunofluorescent staining assessed the secretion of sulfated glycosaminoglycan (GAGs) and collagen type II (Col2) in the cell‐laden hybrid constructs over time. Second, optimization of inline PCI‐CT was performed by investigating three sample‐to‐detector distances (SDD): 0.25, 1 and 3 m. Then, the optimal SDD was utilized to visualize structural changes in the constructs over a 42‐day culture period. The results showed that there was progressive secretion of cartilage‐specific ECM by ATDC5 cells in the hybrid constructs over time. An SDD of 3 m provided edge‐enhancement fringes that enabled simultaneous visualization of all components of hybrid constructs in aqueous solution. Structural changes that might reflect formation of ECM also were evident in SR‐inline‐PCI‐CT images. Summarily, SR‐inline‐PCI‐CT images captured at the optimized SDD enables visualization of the different components in hybrid cartilage constructs over a 42‐day culture period.     

A One‐Pot Synthesis of 1,2‐Dihydroisoquinoline Derivatives from Isoquinoline via a Four‐Component Reaction

A four‐component reaction for the synthesis of 1,2‐dihydroisoquinoline derivatives is described. The Huisgen 1,4‐dipolar intermediate, which is produced from isoquinoline and an electron‐deficient acetylene compound 1 , reacts with H₂O in the presence of diketene to produce 1,2‐dihydroisoquinoline derivatives 2 (Scheme 1). In addition, reaction of isoquinoline, dibenzoylacetylene (=1,4‐diphenylbut‐2‐yne‐1,4‐dione), and diketene in the presence of H₂O leads to pyrroloisoquinoline derivative 7 . The structures of the compounds 2a – f and 7 were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, EI‐MS) and by elemental analyses. A plausible mechanism for the reaction is proposed (Schemes 2 and 3).     

Nanosized aptameric cavities imprinted on the surface of magnetic nanoparticles for high-throughput protein recognition

The authors introduce a new kind of surface artificial biomimetic receptor, referred to as aptameric imprinted polymer (AIP), for separation of biological macromolecules. Highly dispersed magnetic nanoparticles (MNPs) were coated with silica and then functionalized with methacrylate groups via silane chemistry. The aptamer was covalently immobilized on the surface of nanoparticles via a “thiol-ene” click reaction. Once the target analyte (bovine serum albumin; BSA) has bound to the aptamer, a polymer is created by 2-dimensional copolymerization of short-length poly(ethylene glycol) and (3-aminopropyl)triethoxysilane. Following removal of BSA from the polymer, the AIP-MNPs presented here can selectively capture BSA with a specific absorbance (κ) as high as 65. When using this AIP, the recovery of BSA from spiked real biological samples is >97%, and the adsorption capacity is as high as 146 mg g^?1. In our perception, this method has a wide scope in that it may be applied to the specific extraction of numerous other biomolecules.

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Graphical abstract Schematic presentation of the AIP (aptamer-imprinted polymer) introduced here. The surface of silica coated magnetic nanoparticles is modified with a polymer that is covalently modified with an aptamer against bovine serum albumin (BSA).

     

The substitution effect on heavy versions of cyclobutadiene

The structural and electronic characteristics of the M₄R₄ with M = C, Si, Ge and R = H, F, Cl, OH, MgH, BH₂, NH₂ Li are studied by ab initio calculations based on density functional theory using the hybrid B3LYP functional and 6‐311++G* basis set. The results of natural bond orbital analysis (NBO), the analysis of structural parameters (bond lengths and bond angle, dihedral angle), atoms in molecules based theory (AIM) topological parameters such as the characteristics of bond critical points (electron densities and their Laplacians) leads to the conclusion that interamolecular interaction due with OH, MgH₂, and NH₂ substitutions are different from other derivatives. The cyclobutadiene ring and its heavy versions display very different geometrical structures. The cations and anions of C₄R₄, Si₄R₄, and Ge₄R₄ were studied to determine the effect of substitution on structure and stability. It has been shown that substitutions with ability of forming hydrogen bonds, bound to the silicon and germanium atoms are able to change the properties of the four‐member rings more than the other substitutions. Comprehensive analyses of calculated NICS (nucleus‐independent chemical shifts), polarizability, electrophilicity, and electron density are done. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Spectroscopic, Thermal and Structural Studies of Cocrystals of 2,2′-Diamino-4,4′-bis(1,3-thiazole) with 2,5-Bis(4-pyridyl)-3,4-Diaza-2,4-Hexadiene and 1,2-Bis(4-pyridyl)Ethylenediamine

Abstract  

Two cocrystals of 2,2′-diamino-4,4′-bis(1,3-thiazole) (DABTZ) with 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh) and 1,2-bis(4-pyridyl)ethylenediamine (bpen) {[(DABTZ)(bpdh)] and [(DABTZ)(bpen)], respectively} have been synthesized and characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR spectroscopy and were studied by thermal analysis and X-ray crystallography. Self-assembly of these compounds in the solid state is likely caused by hydrogen bonding with minor contributions from π–π stacking, C–H···π and possibly charge transfer interactions.     

Anion‐binding properties of two calix[4]arene derivatives containing two ferrocene imine or ferrocene amine units at the upper rim

Calix[4]arene derivatives containing ferrocene units at the upper rim have been synthesized and their anion‐binding and sensing investigated towards anions such as chloride, bromide and hydrogen sulfate by cyclic voltammetry. Electrochemical studies show that these redox‐active ligands electrochemically recognize chloride and bromide anions. These compounds have excellent selectivity for chloride and bromide ions, in the comparison with hydrogen sulfate anion. With ferrocenyl Schiff base calix[4]arene 1 an anodic shift as large as 302 mV is observed on addition of four equivalents of Cl⁻ anion. Also electrochemical and UV–vis spectroscopic titrations ferrocenyl calix[4]arene derivatives 1 with chloride and bromide ions and 2 (only with Cl⁻) indicate a 1:1 binding‐stiochiometry. Copyright © 2011 John Wiley & Sons, Ltd.