Classical and Advanced Chemical Sciences
Two chelate-forming Schiff bases derived from 4-aminoantipyrine with 4-aminobenzoic acid and benzoin, namely (Z)-4-(4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylideneamino)benzoic acid (HL1) and 4-((E)-4-((E)-((R)-2-hydroxy-1,2-diphenylethylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ylideneamino)benzoic acid (H2L2) were prepared and complexed with copper(II), nickel(II), cobalt(II), manganese(II) and mercury(II)chlorides in ethanol. The M(HL1)2Cl2 and M(HL2)2 type complexes could be isolated. The ligands and theirs metal complexes were characterized using elemental analysis, infrared and electronic, 1H and 13C NMR spectroscopy, molar conductance and magnetic moment measurements. The measurements showed that the HL1 ligand is coordinated in their complexes with N,N-bidendate mode, while HL2 ionic ligand in NNO tridentate pattern through the azomethine nitrogen, amino-group and the depotonated hydroxyl group of benzoin. The stability constants of complexes were determined spectrophotometricaly. All the studies reveal a six coordinated octahedral structure of M(HL2)2 type complexes. In vitro tests for antibacterial and antifungal activities showed that most of the prepared compounds display a good activity towards S. aureus, E. coli, B. subtilis, P. aureginosa, A. niger, A. flavus, R. stolonifer and C. albicans .
Keywords: Benzoin; 4-aminobenzoic acid; 4-aminoantipyrine; Schiff bases, metal complexes; biological activity
This study is concerned with the synthesis and characterization of γ-lactams (3a-3h). γ-Lactams were prepared by reacting phenylsuccinic anhydride with the appropriate Schiff bases (imines) by heating at 51-61 °C in chloroform with moderate yields (51-75 %). The structures of these compounds were established on the basis of the spectral studies using IR, 1H-NMR, 13C-NMR , 13C- NMR DEPT and MS.
Keywords: γ- lactams, imines, NMR
The amination of α-olefins (C4-C7) in the NН2OH·HCl-TiCl3 oxidation-reduction system was investigated and a number of mono- and diamines were prepared. It has been found that in the attack of NH2-radical to olefin a hydrogen migration from first carbon to second one takes place. It has been shown that in the reaction products, besides the desired individual amines, telomers, the molecular masses of which are approximately within the ranges of Мn = 460-800, were also detected
Keywords: α-olefins, 1,2-hydrogen migration, diamines, telomers
Materials and Environmental Chemistry
We report the synthesis of graphene oxide by the electrochemical method. The standard redox potentials of the carboxyl groups of carbon is used to select the oxidation potential. Graphene oxide obtained by anodic oxidation of multiwall carbon nanotubes in concentrated sulfuric acid, confirmed by electron microscopy, XRD, X-ray photoelectron spectroscopy, X-ray emission spectroscopy and Raman spectra, is a prospective electrode material for the chemical current sources. The oxidation potential in 96 % sulfuric acid is +3 V and the time of oxidation was 4 h. A good electrical conductivity is observed because of the presence of fragments of carbon nanotube in graphene oxide. Thus, this material is a very promising electrode material for oxygen electrodes. The current–voltage characteristics of the oxygen electrodes, based on electrochemically produced graphene oxide, is the graphene oxide produced by anodic oxidation of multiwall carbon nanotubes.
Keywords: Anodic oxidation of carbon nanotubes, Graphene oxide, Electrode materials, Oxygen electrode
The influence of the shape of magnetic particles and dielectric permittivity of the medium is investigated on the magneto-optical properties of the nano-dispersive structures using the thin discontinuous Co films. The behaviour of the magneto-optical spectra of thin Co films was explained in the framework of the effective medium approximation. The results have confirmed the significant change of the components of the tensor of effective dielectric permittivity and subsequently of the magneto-optical and optical properties which brought about the change of the shape of magnetic particles. These calculations proved that a good agreement between the experimental results and the theoretical calculations is achieved if the shape of the particles is taken into account.
Keywords: Magneto-optical spectra, Effective medium approximation, Thin metal films
Chemical and Biological Aspects of Life
Aromatic heterocycles especially indole plays an important part in treatment of cancer. This review highlights compounds in development bearing indole moiety in their scaffold for the treatment of cancers. This review also highlights the utilization of colchicine binding site in order to inhibit tubulin polymerization. Docking studies shows that colchicine binding site is used by various indole derivatives to exert their action. Vincristine and vinblastine are the natural compounds which have the anticancer activity but they act on the vinca domain of the tubulin protein. Vinca domain can be too large for small ligands, so small molecules can utilize colchicines binding site to inhibit microtubule polymerization.
Keywords: Vincristine; docking; Colchicine; Tubulin
Polycystic ovary syndrome (PCOS) is a common hormonal disorder characterized by gonadotropin dysregulation, hyperandrogenism, menstrual irregularity and ovarian morphology. The uncoupling protein-2 (UCP-2) gene is a member of the mitochondrial anion carrier protein (MACP) and is strongly associated with insulin resistance and obesity. An attempt is made to detect the association between PCOS and -866G/A polymorphism in UCP2 gene promoter. The study is carried on forty-seven patients with polycystic ovary syndrome and fifty–six controls. Blood samples were taken for biochemical tests and restriction fragment length polymorphism (RFLP) for detection of -866 G/A UCP2 gene polymorphisms. Significant associations between the -866A/A -866G/A of UCP2 gene promotor and PCOS are reported including a significant association between -866A/A polymorphism of UCP2 and both obesity (high BMI) and type 2 diabetes.
Keywords: polycystic ovary syndrome; single nucleotide polymorphism; type 2 diabetes; obesity