Dioxomolybdenum(VI) complexes of dibasic tridentate Schiff bases having the HO-N-OH donor system

Summary The synthesis and structural features of some dibasictridentate Schiff base complexes of dioxomolybdenum of the type MoO₂L and MoO₂L·DMSO are described. The ligands, LH₂ were derived by the condensation of 2-hydroxy-1-naphthaldehyde, 2,4-pentanedione and 2-hydroxyacetophenone with glycine or -alanine. The new complexes were characterized by elemental analysis, conductance, molecular weight and magnetic measurements. Based on i.r.,¹H n.m.r.,¹³C n.m.r. studies, a pseudooctahedral and octahedral structure is proposed for MoO₂L and MoO₂L·DMSO respectively.     

Patterned assembly of Yarrowia lipolytica yeast cells onto thermally evaporated octadecylamine films

Thermally evaporated patterned films of the lipid, octadecylamine (ODA), have been used in the immobilization of the hydrocarbon-degrading cells, Yarrowia lipolytica. The immobilization of the yeast cells occurs on hydrophobic surfaces presented by the lipid film elements in the patterned structure, the attachment of the cells to the lipid film occurring possibly through hydrophobic interactions between the hydrocarbon chains of the fatty amine film and the cell wall of the yeasts. It is observed that the cell immobilization is extremely faithful to the underlying lipid template indicating potential use in tissue engineering as well as materials applications involving specific enzyme-based biotransformations.     

Trichlorooxovanadium(V) derivatives of thio-Schiff bases

Summary The synthesis and characterization of five- and six-coordinate oxovanadium(V) complexes of the type [(VOCl₂)(TSCZ)] and [(VOCl)(TSCZ)₂] (where HTSCZ represents thiosemicarbazones of furfuraldehyde, pyridine-2-aldehyde, thiophene-2-aldehyde and cinnamaldehyde) are reported. On the basis of i.r., u.v.,¹H and¹³C n.m.r. spectral studies, distorted trigonal bipyramidal and octahedral geometries are proposed for [(VOCl₂)(TSCZ)] and [(VOCl)(TSCZ)₂], respectively.     

Gold nanoparticles modified indium tin oxide electrode for the simultaneous determination of dopamine and serotonin: Application in pharmaceutical formulations and biological fluids

A new rapid, convenient and sensitive electrochemical method based on a gold nanoparticles modified ITO (Au/ITO) electrode is described for the detection of dopamine and serotonin in the presence of a high concentration of ascorbic acid. The electrocatalytic response was evaluated by differential pulse voltammetry (DPV) and the modified electrode exhibited good electrocatalytic properties towards dopamine and serotonin oxidation with a peak potential of 70 mV and 240 mV lower than that at the bare ITO electrode, respectively. The selective sensing of dopamine is further improved by applying square wave voltammetry (SWV) which leads to the lowering of its detection limit. A similar effect on the detection limit of serotonin was observed on using SWV. Linear calibration curves are obtained in the range 1.0 × 10⁻⁹-5.0 × 10⁻⁴ M and 1.0 × 10⁻⁸-2.5 × 10⁻⁴ M with a detection limit of 0.5 nM and 3.0 nM for dopamine and serotonin, respectively. The Au/ITO electrode efficiently determines both the biomolecules simultaneously, even in the presence of a large excess of ascorbic acid. The adequacy of the developed method was evaluated by applying it to the determination of the content of dopamine in dopamine hydrochloride injections. The proposed procedure was also successfully applied to simultaneously detect dopamine and serotonin in human serum and urine.     

Low-Temperature Synthesis of Solution Processable Carbon Nitride Polymers

Carbon nitride materials require high temperatures (>500 °C) for their preparation, which entails substantial energy consumption. Furthermore, the high reaction temperature limits the materials’ processability and the control over their elemental composition. Therefore, alternative synthetic pathways that operate under milder conditions are still very much sought after. In this work, we prepared semiconductive carbon nitride (CN) polymers at low temperatures (300 °C) by carrying out the thermal condensation of triaminopyrimidine and acetoguanamine under a N₂ atmosphere. These molecules are isomers: they display the same chemical formula but a different spatial distribution of their elements. X-ray photoelectron spectroscopy (XPS) experiments and electrochemical and photophysical characterization confirm that the initial spatial organization strongly determines the chemical composition and electronic structure of the materials, which, thanks to the preservation of functional groups in their surface, display excellent processability in liquid media.     

A preliminary study of soft cheese degradation in different packaging conditions by 1H-NMR

This preliminary work deals with the influence of packaging on the degradation of an Italian soft cheese studied by NMR. The NMR profiles of aqueous cheese extracts were acquired as a function of time during storage of cheese inside and outside the original package. From the NMR spectra 15 metabolites are quantified and used in a kinetic degradation model and in a multivariate algorithm in order to evaluate the changes in the metabolic composition of cheese stored under different conditions.     

Synthesis of Carvacrol Derivatives as Potential New Anticancer Agent against Lung Cancer

Lung cancer remains a major public health concern among all cancer diseases due to the toxicity and side-effects of the available commercially synthesized drugs. Natural product-derived synthesized anticancer drugs are now of promising interest to fight against cancer death. Carvacrol is a major component of most essential oil-bearing plants with potential pharmacological activity, especially against various cancer cell lines. Among the other organometallic compounds, copper complexes have been reported to be effective anticancer agents against various cancer cell lines, especially lung and leukemia cancers, due to the nontoxic nature of copper in normal cells since it is an endogenic metal. In this study, we synthesized three carvacrol derivatives, i.e., carvacrol aldehyde, Schiff base, and copper–Schiff base complex, through an established synthesis protocol and characterized the synthesized product using various spectroscopic techniques. The synthesized derivatives were evaluated for in vitro cytotoxic activity against different cancer cell lines, including human lung cancer (A549) and human fibroblast (BALB-3T3). Our findings showed that the copper–Schiff base complex derived from carvacrol inhibited the proliferation and migration of the A549 cell lines in a dose-dependent manner. This activity might be due to the inhibition of cell proliferation and migration at the G₂/M cell-cycle phase, as well as apoptosis, possibly through the activation of the mitochondrial apoptotic pathway. To our knowledge, this is the first report on the activity of the copper–Schiff base complex of carvacrol against A549 cell lines. Our result highlights that a new synthesized copper complex from carvacrol could be a novel potential drug in the treatment of lung cancer.     

Facile synthesis of hollow urchin-like Nb2O5 nanostructures and their performance in dye-sensitized solar cells

Journal of Solid State Electrochemistry - In present study, hollow urchin-like nanostructures of Nb2O5 with elongated nanofilaments as photoanode material for dye-sensitized solar cells (DSSCs) are...     

One-Pot Synthesis of 3,4-Dihydropyridin-2-one via Michael Addition of in situ–Generated Enaminones

Herein we have reported a facile solvent-, catalyst-, and aldehyde-free, one-pot synthesis of 3,4-dihydropyridin-2-one from 1,3-diones using simple and mild reaction conditions. The substrate scope has been also extended to β-ketoesters.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]