Spectroscopic, structure and antimicrobial activity of new Y(III) and Zr(IV) ciprofloxacin

The preparation and characterization of the new solid complexes [Y(CIP)2(H2O)2]Cl(3)·10H2O and [ZrO(CIP)2Cl]Cl·15H2O formed in the reaction of ciprofloxacin (CIP) with YCl3 and ZrOCl(2)·8H2O in ethanol and methanol, respectively, at room temperature were reported. The isolated complexes have been characterized with elemental analysis, IR spectroscopy, conductance measurements, UV-vis and 1H NMR spectroscopic methods and thermal analyses. The results support the formation of the complexes and indicate that ciprofloxacin reacts as a bidentate ligand bound to the metal ion through the pyridone oxygen and one carboxylato oxygen. The activation energies, E*; entropies, ΔS*; enthalpies, ΔH*; Gibbs free energies, ΔG*, of the thermal decomposition reactions have been derived from thermogravimetric (TGA) and differential thermogravimetric (DTG) curves, using Coats-Redfern and Horowitz-Metzeger methods. The proposed structure of the two complexes was detected by using the density functional theory (DFT) at the B3LYP/CEP-31G level of theory. The ligand as well as their metal complexes was also evaluated for their antibacterial activity against several bacterial species, such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) and antifungal screening was studied against two species (Penicillium (P. rotatum) and Trichoderma (T. sp.)). This study showed that the metal complexes are more antibacterial as compared to free ligand and no antifungal activity observed for ligand and their complexes.     

Synthesis and antitumor activity evaluation of some 1, 2, 4-triazine and fused triazine derivatives

Reactions of 3-hyrazino-5,6-diphenyl-1,2,4-triazine with various carbonyl compounds such as ethyl acetoacetate, acetylacetone, benzoin, isatin, phthalic anhydride, phenyl isocyanate and acetic anhydride were discussed. Its reactions with α, β unsaturated compounds such as arylidinemalononitrile, diethyl acetylenedicarboxylate, dibenzylidine hydrazine were studied. These reactions led to the formation of various triazine and fused-triazine derivatives. The antitumor activity of the synthesized compounds was tested against HePG2 and MCF-7 cell lines. Some of the tested compounds were most active, whereas other compounds exhibited little or no activity.     

A 3D model of the cyclic thermomechanical behavior of shape memory alloys

The model in the first part of this paper is extended to account for SMA behavior under cyclic loading. To this end, three new state variables are introduced: internal stress B, residual strain ?_r and cumulated martensite volume fraction z_e. Several parameters of the extended model depend on z_e, making them evolve with cyclic phase change. Cyclic SMA effects including training and two-way shape memory are accounted for and several numerical simulations are provided and validated in the case of cyclic superelasticity.     

Synthesis and antimicrobial activity of substituted [(pyrazol‐4‐yl)methylene]hydrazono‐2,3‐dihydrothiazoles and their sugar derivatives

A number of new [(pyrazol‐4‐yl)methylene]hydrazono‐2,3‐dihydrothiazole derivatives, their sugar hydrazones and N‐glycosides were synthesized. Furthermore, N‐substituted oxygenated alkyl and hydroxyl derivatives and 1,3,4,‐oxadiazoline acyclic nucleoside analogs were prepared. The newly synthesized compounds were tested for their antimicrobial activities and showed moderate to high inhibition activities. J. Heterocyclic Chem., (2012).     

Synthesis and Antimicrobial Activity of New 1,2,3‐Triazolopyrimidine Derivatives and Their Glycoside and Acyclic Nucleoside Analogs

New [1,2,4‐oxadiazolyl]methyl‐3H‐[1,2,3]triazolo[4,5‐d]pyrimidin derivatives were synthesized starting from N′‐Hydroxy‐1‐naphthimidamide. The N‐substituted acyclic nucleoside analogs as well as the substituted glycosides were also prepared by reaction with the corresponding reagents. The antimicrobial results indicated that most of the tested compounds exhibited moderate to high antimicrobial activity whereas few compounds were found to exhibit little or no activity against the tested microorganisms.     

Garlic Powder as a Safe Environment Green Corrosion Inhibitor for Mild Steel in Acidic Media; Adsorption and Quantum Chemical Studies

The corrosion inhibition of mild steel in H3PO4 solution by garlic powder was investigated using weight loss and polarization techniques. The adsorption of garlic powder was found to obey Langmuir adsorption isotherm. Maximum inhibition efficiency was 75% at 50 °C and 250 ppm inhibitor concentration. The values of heat of adsorption were negative indicating the spontaneous adsorption process. Quantum chemical calculations were used successfully to evaluate the theoretical inhibitor efficiency. Mathematical and statistical analyses were also used to represent the corrosion rate data with high correlation coefficients. Polarization measurements showed that garlic powder was a mixed — type inhibitor.