Properties of mouse vomeronasal receptor and assessment of its role in pheromone signalling

Vomeronasal type 2 receptor (V2Rx) from Swiss mouse (Mus musculus (L.)) was analyzed by high-resolution ion-exchange chromatography, reversed-phase high-performance liquid chromatography (RP-HPLC), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), Ion Spray tandem mass spectrometry (MS/MS), 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 1-aminoanthracene (1-AMA) fluorometric assay. Vomeronasal sensory neuronal cell bound proteins were resolved into major protein peaks. Several proteins were identified and subsequently purified as the V2Rx receptor on 10% SDS-PAGE with trace amounts of other protein bands. The molecular weight of the identified V2Rx was 109 kDa. MALDI-TOF and micro-sequencing experiments demonstrated that the identified V2Rx receptor shared considerable sequence similarity with vomeronasal receptor type 2 (NCBI Accession Number AB267725), which is a seven transmembrane peptide with 912 amino acid residues. The molecular characterization revealed that the N-terminus of the V2Rx receptor contained the 11GAEAAE16 domain involved in pheromone signalling. The biometric assay (octanamine-V2Rx binding) showed the identified V2Rx receptor and mouse sex pheromone to 2-octanamine (methyl heptyl) in a 1:1 ratio. Uptake of odourants determined in physiological condition showed enhanced V2Rx receptors as volatile hydrophobic pheromone receptors in the vomeronasal neuron of the Swiss mouse.     

SnCl2-catalyzed selective atom economic imino Diels-Alder reaction: synthesis of 2-(1H-pyrrolo[2,3-b]pyridin-3-yl)quinolines

The synthesis of 2-(1H-pyrrolo[2,3-b]pyridin-3-yl)quinolines by a SnCl(2)-catalyzed multicomponent reaction has been described. The reaction proceeds chemo- and regioselectively in an atom-economic way, generating a library of 24 quinoline derivatives.     

Copper(I)-catalyzed cascade sulfonimidate to sulfonamide rearrangement: synthesis of imidazo[1,2-a][1,4]diazepin-7(6H)-one

A novel strategy of copper(I)-catalyzed cascade intramolecular nucleophilic attack on N-sulfonylketenimine followed by rearrangement of sulfonimidates to sulfonamides resulting in a library of substituted 8,9-dihydro-5H-imidazo[1,2-a][1,4]diazepin-7(6H)-ones has been developed.     

Nucleophilic substitution reaction of Morita–Baylis–Hillman adducts of isatin with X,S, N,and O-nucleophiles: a facile and efficient synthesis of highly functionalized tetrasubstituted alkene appended oxindoles

The Morita–Baylis–Hillman adducts derived from isatins and maleimides have undergone a facile and efficient allylic nucleophilic substitution reaction with X, S, N, and O-nucleophiles to afford functionalized tetrasubstituted alkene appended oxindoles in very good yield. The MBH adducts and their acetates on treatment with halides, saturated and unsaturated amines, thiols, and trialkyl orthoformates afforded allyl halide, allyl amine, allyl thio-ether and allyl ether derivatives of oxindole, respectively.     

Copper catalysed domino decarboxylative cross coupling-cyclisation reactions: synthesis of 2-arylindoles

The efficient synthesis of 2-arylindoles and 6H-isoindolo[2,1-a]indol-6-one through copper catalysed domino sp-sp² decarboxylative cross-coupling and subsequent cyclisation reactions of arylpropiolic acids with 2-iodotrifluoroacetanilide has been described. This methodology also demonstrates that indolo[1,2-c]quinazolin-6(5H)-one can be obtained with the elimination of trifluoromethyl anion.     

Microwave‐Assisted Stereoselective 1,3‐Dipolar Cycloaddition of C,N‐Diarylnitrone (i.e., N‐(Arylmethylidene)benzenamine N‐Oxide) and Bis(arylmethylidene)acetone (=1,5‐Diarylpenta‐1,4‐dien‐3‐one): NMR and Crystal Analysis of Diastereoisomeric Bis(isoxazolidines)

Microwave‐assisted stereoselective 1,3‐dipolar cycloaddition of C,N‐diarylnitrones (i.e., N‐(arylmethylidene)benzenamine N‐oxides) 2 to substituted bis(arylmethylidene)acetones (=1,5‐diarylpenta‐1,4‐dien‐3‐ones) 1 leading to diastereoisomer pairs of bis‐isoxazolidines 3 and 4 in good to excellent yield is described (Scheme 2 and Table 2). The configuration outcome of the reaction is discussed based on the NMR and X‐ray data of the products.     

Electrical and optical properties of pure and Pb2+ ion doped PVA???PEG polymer composite electrolyte films

Pb²⁺ ion conducting polymer composite electrolyte films, based on polyvinyl alcohol and polyethylene glycol doped with Pb(NO₃)₂ salt, were prepared using the solution cast technique. X-ray diffraction patterns of polymer composite with salt reveal the decrease in the degree of crystallinity with increasing concentration of the salt. The dielectric plots show an increase in dielectric permittivity at low frequency side with increasing salt concentration as well as temperature. The frequency dependence of ac conductivity obeys the Jonscher power law, and the maximum dc conductivity value is found to be 2.264×10^?7 S/m at 303?K for the polymer composite with 30?mol% Pb(NO₃)₂. The activation energy for the ion in polymer electrolyte has been calculated from the modulus plots, and is in good agreement with the activation energy calculated from the temperature-dependent dc conductivity plot. The modulus plots indicate the non-Debye nature of the sample. For pure and doped films at room temperature, the impedance plots exhibit only one semicircle, indicating the presence of one type of conduction mechanism, whereas for 30?mol% salt doped with electrolyte film at different temperatures, it demonstrated the existence of bulk and electrode?Celectrolyte interface properties. Optical absorption spectra show a broad peak for all complexes, while compared with pure polymer composite, due to the complex formation of polymer electrolyte with Pb(NO₃)₂ and their absorption edge, direct band gap and indirect band gap were calculated. It was found that the absorption edge and energy gap values decreased on doping with Pb(NO₃)₂ dopant.     

Effect of surface charge of magnetite nanoparticles on their internalization into breast cancer and umbilical vein endothelial cells

Internalization of magnetite nanoparticles with diameter of approximately 40 nm into normal and cancer cells was examined by microscopic observation and flow cytometry. Magnetite nanoparticles were synthesized by hydrolysis in an aqueous solution containing ferrous chloride with organic amines as a base. It was demonstrated that the difference in surface charge of magnetite nanoparticles brought about the difference in uptake efficiency. The nanoparticles with positive charge showed higher internalization into human breast cancer cells than the nanoparticles with negative charge, while the degree of internalization of the positively- and negatively-charged nanoparticles into human umbilical vein endothelial cells (HUVEC) was almost the same.     

Phosphotungstic acid mediated,microwave assisted solvent-free green synthesis of highly functionalized 2ˈ-spiro and 2, 3-dihydro quinazolinone and 2-methylamino benzamide derivatives from aryl and heteroaryl 2-amino amides

Phosphotungstic acid has been found as green catalyst for the synthesis of spiro and cyclized quinazolinones and 2-amino substituted carboxamide under microwave irradiation and solvent-free condition has been developed. The scope of the reaction has been demonstrated for a variety of aldehydes and ketones with O-amino amides such as 2-amino-benzamide, 2-amino-5-iodo benzamide, 3-aminothiophene-2-carboxamide, 3-aminobenzofuran-2-carboxamide and 2-aminopyridine-3-carboxamides. The reaction afforded spiro-, cyclized quinazolinones and 2-amino substituted carboxamide derivatives within few minutes of irradiation in excellent yield. Plausible mechanism for the formation of products is provided. Synthetic utility of 1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 3a has been demonstrated by synthesis of 1,4-di(1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one) buta-1,3-diyne 12, 1′-((1-benzyl-1H-1,2,3-triazol-4-yl) methyl)-1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 13 and 1′-phenyl-1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 14 under standard protocols.