Crystal structure of 4,4'-diethynylbiphen-yl

The title compound, C16H10, crystallizes with four unique mol-ecules, designated 1-4, in the asymmetric unit of the monoclinic unit cell. None of the mol-ecules is planar, with the benzene rings of mol-ecules 1-4 inclined to one another at angles of 42.41 (4), 24.07 (6), 42.59 (4) and 46.88 (4)°, respectively. In the crystal, weak C-H⋯π(ring) interactions, augmented by even weaker C C-H⋯π(alkyne) contacts, generate a three-dimensional network structure with inter-linked columns of mol-ecules formed along the c-axis direction.

A mononuclear zinc(II) complex with piroxicam: crystal structure, DNA- and BSA-binding studies; in vitro cell cytotoxicity and molecular modeling of oxicam complexes

A new mononuclear Zn(II) complex, trans-[Zn(Pir)2(DMSO)2], where Pir(-) is 4-hydroxy-2-methyl-N-2-pyridyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (piroxicam), has been synthesized and characterized. The crystal structure of the complex was obtained by the single crystal X-ray diffraction technique. The interaction of the complex with DNA and BSA was investigated. The complex interacts with FS-DNA by two binding modes, viz., electrostatic and groove binding (major and minor). The microenvironment and the secondary structure of BSA are changed in the presence of the complex. The anticancer effects of the seven complexes of oxicam family were also determined on the human K562 cell lines and the results showed reasonable cytotoxicities. The interactions of the oxicam complexes with BSA and DNA were modeled by molecular docking and molecular dynamic simulation methods.

Successful percutaneous closure of spiral atrial septal defect

The case report of a 15-year-old patient with an unusual form of atrial septal defect is described. Echocardiography showed separation of the secundum and primum atrial septums due to abnormal posterior and leftward attachment of the primum septum into the roof of the left atrium. The morphology has been variably described as a 'double' atrial septum or 'spiral' atrial septal defect. Despite the technical challenge of this form of atrial septal defect, it was effectively closed by ensuring that all relevant septal structures were incorporated between the discs of the occlusion device. This was associated with a stable position and good medium-term outcome. This contrasts with the experience of others where device embolisation or technical failure has been described.

LEARNING POINTS

The spiral atrial septal defect is characterised by an apparently 'double' atrial septum.Such atrial septal defects (ASDs) have been associated with a high rate of technical failure of transcatheter closure.3D echocardiography assists in understanding the anatomy of the defect.Following deployment of the ASD occlusion device transoesophageal echocardiography is essential to ensure that both septum primum and secundum are between the occluder discs.Catheter closure can be successful if close attention is paid to the morphology of the defect and incorporation of margins within the discs of the septal occluder.

Experimental and molecular modeling studies of the interaction of the polypyridyl Fe(II) and Fe(III) complexes with DNA and BSA

Two mononuclear iron complexes, [Fe(tppz)₂](PF₆)₂·H₂O (1) and Fe(tppz)Cl₃·2CHCl₃ (2) where tppz is (2,3,5,6-tetra(2-pyridyl)pyrazine), have been synthesized and characterized by elemental analysis, spectroscopic methods (UV-Vis and IR) and single crystal X-ray structure analysis. The interaction of (1) as the nitrate salt ([Fe(tppz)₂](NO₃)₂) with calf-thymus DNA (CT-DNA) has been monitored by UV-Vis spectroscopy, competitive fluorescence titration, circular dichroism (CD), voltammetric techniques, viscosity measurement, and gel electrophoresis. Gel electrophoresis of DNA with [Fe(tppz)₂](NO₃)₂ demonstrated that the complex also has the ability to cleave supercoiled plasmid DNA. The results have indicated that the complex binds to CT-DNA by three binding modes, viz., electrostatic, groove and partial insertion of the pyridyl rings between the base stacks of double-stranded DNA. Molecular docking of [Fe(tppz)₂](NO₃)₂ with the DNA sequence d(ACCGACGTCGGT)₂ suggests the complex fits into the major groove. The water-insoluble complex (2) can catalyze the cleavage of BSA at 40 °C. There are no reports of the catalytic effect of polypyridyl metal complexes on the BSA cleavage. Molecular docking of (2) with BSA suggests that, when the chloro ligands in the axial positions are replaced by water molecules, the BSA can interact with the Fe(III) complex more easily.

Combination of Pyridinium and Isoquinolinium Ylides with Phenylisocyanate and Isothiocyanates: Synthesis, Characterisation, and X-Ray Crystal Structures of Mesoionic Monosubstituted 3-Oxo-Propanamides or Thioamides

Pyridinium ylides derived from 2-bromoacetophenone or methyl bromoacetate have been reacted with phenylisocyanate, phenyl- or methylisothiocyanate to afford mesoionic monosubstituted 3-oxo-propanamides or thioamides, via self-protonation of the intermediate N-anion. A similar reaction under the same conditions of isoquinolinium ylides with phenylisocyanate or phenyisothiocyante also produced the corresponding mesoionic compounds. In order to establish the exact structure of the mesoionic compounds, single crystal X-ray structures were obtained for three of the pyridinium ylides.

Influence of the diversified structural variations at the imine functionality of 4-bromophenylacetic acid derived hydrazones on alkaline phosphatase inhibition: synthesis and molecular modelling studies

Putative binding mode of 4g inside the active pocket of h-PLAP.

Crystal structure of (Z)-2-[(E)-2-benzyl-idene-hydrazin-1-yl-idene]-1,2-di-phenyl-ethanone

The title compound, C21H16N2O, has an almost planar (r.m.s. deviation = 0.0074 Å) 1,2-di-benzyl-idenehydrazine backbone with an approximately orthogonal almost planar (r.m.s. deviation = 0.0368 Å) phenyl-ethanone substituent on one of the imine C atoms. The dihedral angle between the two mean planes is 76.99 (4)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds and C-H⋯π contacts, forming a three-dimensional structure with mol-ecules stacked along the a-axis direction.

New triazolothiadiazole and triazolothiadiazine derivatives as kinesin Eg5 and HIV inhibitors: synthesis, QSAR and modeling studies

A new series of fused 1,2,4-triazoles, namely 6-aryl-3-(furan-2-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 3a–h and 4a–f as well as 6-aryl-3-(furan-2-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines 5a–h, were synthesized by the condensation of 4-amino-5-(furan-2-yl)-4H-1,2,4-triazole-3-thiol (2) with substituted aromatic acids and phenacyl bromides, respectively. The structures of the newly synthesized compounds were established using spectroscopic analysis, while that of 3e was confirmed independently by a single-crystal X-ray structure determination. The compounds were evaluated for their antiviral activity against the replication of HIV-1 and HIV-2 in MT-4 cells using an MTT assay. In a docking study, 4b interacted with several amino acids in the reverse transcriptase (RT) binding site of HIV-1. Some new analogues were selected for evaluation of their Eg5 inhibitory activity using an in vitro malachite green ATPase assay. The QSAR of these new analogues was studied as well.

Synthesis, physiochemical characterization, and biocompatibility of a chitosan/dextran-based hydrogel for postsurgical adhesion prevention

An amine-functionalized succinyl chitosan and an oxidized dextran were synthesized and mixed in aqueous solution to form an in situ chitosan/dextran injectable, surgical hydrogel for adhesion prevention. Rheological characterization showed that the rate of gelation and moduli were tunable based on amine and aldehyde levels, as well as polymer concentrations. The CD hydrogels have been shown to be effective post-operative aids in prevention of adhesions in ear, nose, and throat surgeries and abdominal surgeries in vivo. In vitro biocompatibility testing was performed on CD hydrogels containing one of two oxidized dextrans, an 80 % oxidized (CD-100) or 25 % (CD-25) oxidized dextran. However, the CD-100 hydrogel showed moderate cytotoxicity in vitro to Vero cells. SC component of the CD hydrogel, however, showed no cytotoxic effect. In order to increase the biocompatibility of the hydrogel, a lower aldehyde level hydrogel was developed. CD-25 was found to be non-cytotoxic to L929 fibroblasts. The in vivo pro-inflammatory response of the CD-25 hydrogel, after intraperitoneal injection in BALB/c mice, was also determined by measuring serum TNF-α levels and by histological analysis of tissues. TNF-α levels were similar in mice injected with CD-25 hydrogel as compared to the negative saline injected control; and were significantly different (P < 0.05) as compared to the positive, lipopolysaccharide, injected control. Histological examination revealed no inflammation seen in CD hydrogel injected mice. The results of these in vitro and in vivo studies demonstrate the biocompatibility of the CD hydrogel as a post-operative aid for adhesion prevention.

Crystal structure of 2-(4-chloro-phen-yl)-2-oxoethyl 3-bromo-benzoate

2-(4-Chloro-phen-yl)-2-oxoethyl 3-bromo-benzoate, C15H10BrClO3, was synthesized in a single-step reaction by condensation of 3-bromo-benzoic acid with 2-bromo-1-(4-chloro-phen-yl)ethanone in di-methyl-formamide in the presence of tri-ethyl-amine as a catalyst. The structure consists of an aryl ketone moiety linked to an aryl ester unit by a methyl-ene group. Both units are reasonably planar (r.m.s. deviations of 0.119 and 0.010 Å for the aryl ketone and aryl ester units, respectively) and are almost orthogonal, with an angle of 88.60 (3)° between them. In the crystal, mol-ecules form five separate sets of inversion dimers. Three of these are generated by two C-H⋯O inter-actions and a C-H⋯Br contact, and form chains along c and along the ab cell diagonal. In addition, two inversion-related π-π stacking inter-actions between like aryl rings again form chains of mol-ecules but in this instance along the bc diagonal. These contacts generate infinite layers of mol-ecules parallel to (011) and stack the mol-ecules along the a-axis direction.