Solvent dependence of absorption intensities and wavenumbers of the fundamental and first overtone of NH stretching vibration of pyrrole studied by near-infrared/infrared spectroscopy and DFT calculations

Near-infrared (NIR) and IR spectra were measured for pyrrole in CCl(4), CHCl(3), and CH(2)Cl(2) to study solvent dependence of absorption intensities and wavenumbers of the fundamental and first overtone of NH stretching vibration. It was found that the wavenumbers of the NH fundamental and its first overtone decrease in the order of CCl(4), CHCl(3), and CH(2)Cl(2), which is the increasing order for of the dielectric constant of the solvents. Their absorption intensities increase in the same order, and the intensity increase is more significant for the fundamental than the overtone. These results for the solvent dependence of the wavenumbers and absorption intensities of NH stretching bands of pyrrole are quite different from those due to the formation of hydrogen bonds. Quantum chemical calculations of the wavenumbers and absorption intensities of NH stretching bands by using the 1D Schr?dinger equation based on the self-consistent reaction field (SCRF)/isodensity surface polarized continuum model (IPCM) suggest that the decreases in the wavenumbers of both the fundamental and the overtone of the NH stretching mode with the increase in the dielectric constant of the solvents arise from the anharmonicity of vibrational potential and their intensity increases come from the gradual increase in the slope of the dipole moment function.     

Construction of on-line supercritical fluid extraction with reverse phase liquid chromatography–tandem mass spectrometry for the determination of capsaicin

A column-switching system, composed of supercritical fluid extraction (SFE) and reverse phase liquid chromatography/mass spectrometry (RPLC/MS) was constructed for on-line extraction and reverse-phase separation of capsaicinoids in capsicum fruits.     

Grafting of Polymers from Carbon Fiber. Anionic Graft Polymerization of Vinyl Monomers Initiated by Metallized Aromatic Rings on Carbon Fiber

The anionic graft polymerization of vinyl monomers onto carbon fiber initiated by metallized carbon fiber was investigated. The metalation of polycondensed aromatic rings of the carbon fiber surface was achieved by the treatment of carbon fiber with n-butyl-lithium (BuLi) in N, N, N′, N′ -tetramethylethylenediamine (TMEDA) or hexamethylphosphorous triamide (HMPT) at 0°C. The anionic polymerization of methyl methacrylate (MMA) and styrene (St) was initiated by the metallized carbon fiber, and these polymers were grafted onto the surface. The conversion and the percentage of grafting increased with increasing amount of BuLi used for the metalation of carbon fiber. When 0.20 g carbon fiber was treated with 0.3 mmol BuLi in TMEDA, the percentage of grafting of PMMA and PSt reached a maximum value (PMMA, 34.5%; PSt, 37.1 %). Furthermore, the metalation of aromatic rings of carbon fiber also proceeds by the treatment with BuLi in HMPT. On the contrary, no grafting was observed when carbon fiber was treated with BuLi in tetrahydrofuran (THF) or toluene. This may be due to the fact that metalation of carbon fiber does not proceed in THF or toluene.     

Oxidative kinetic resolution of racemic alkyl aryl carbinols by an electronically tuned chiral nitroxyl radical

A method for oxidative kinetic resolution of racemic alcohols catalyzed by chiral nitroxyl radical (R,R)-1 has been developed. This method is especially effective for the kinetic resolution of tert-butyl aryl carbinols (s = up to 23).     

An artificial virus-like nano carrier system: enhanced endosomal escape of nanoparticles via synergistic action of pH-sensitive fusogenic peptide derivatives

We previously reported that transferrin (Tf)-modified liposomes (Tf-L) additionally modified with a cholesterylated pH-sensitive fusogenic peptide (Chol-GALA) can release an encapsulated aqueous phase marker to cytosol via endosomal membrane fusion. However, further obstacles need to be overcome to bring the Tf-L to the level of a viral-like gene delivery system. In this study, we developed a novel packaging method to encapsulate condensed plasmid DNA into PEgylated Tf-L (Tf-PEG-L) to form a core–shell-type nanoparticle. The most difficult challenge was to provide a mechanism of escape for the condensed core from endosome to cytosol in the presence of polyethylene glycol (PEG). We hypothesized that a membrane-introduced Chol-GALA and a PEgylated GALA would interact synergistically to induce membrane fusion between liposome and endosome. By simultaneously incorporating Chol-GALA into the membrane of Tf-PEG-L and GALA at tips of PEG chains, a condensed core was released into cytosol, and transfection acitivty increased 100-fold. We concluded that topological control was responsible for the synergistic effect of GALA derivatives introduced on Tf-PEG-L. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Kentaro Sasaki and Kentaro Kogure contributed equally to this work.     

Fluorescence Screening of Organophosphorus Pesticides in Water by an Enzyme Inhibition Procedure on TLC Plates

JPC – Journal of Planar Chromatography – Modern TLC - An enzymatic inhibition method sufficiently sensitive for rapid screening of seven organophosphorus pesticides in water is...     

Synthesis, characterization, DNA-binding study and anticancer properties of ternary metal(II) complexes of edda and an intercalating ligand

A series of ternary metal(ii) complexes {M(phen)(edda); 1a (Cu), 1b (Co), 1c (Zn), 1d (Ni); H(2)edda = N,N(')-ethylenediaminediacetic acid} of N,N'-ethylene-bridged diglycine and 1,10-phenanthroline were synthesized and characterized by elemental analysis, FTIR, UV-visible spectroscopy and magnetic susceptibility measurement. The interaction of these complexes with DNA was investigated using CD and EPR spectroscopy. MTT assay results of 1a-1c , screened on MCF-7 cancer cell lines, show that synergy between the metal and ligands results in significant enhancement of their antiproliferative properties. Preliminary results from apoptosis and cell cycle analyses with flow cytometry are reported. seems to be able to induce cell cycle arrest at G(0)/G(1). The crystal structure of 1a is also included.     

The scope and limitation of the regio- and enantioselective hydrolysis of aliphatic epoxides using Bacillus subtilis epoxide hydrolase,and exploration toward chirally differentiated tris(hydroxymethyl)methanol

The substrate specificity of an engineered Bacillus subtilis epoxide hydrolase, which so far had shown high activity and enantioselectivity with 1-benzyloxymethyl-1-methyloxirane, has been studied by altering the methyl substituent into hydrogen, oxygen-containing functionalities, and unsaturated homologs. High enantioselectivity (E = 44) was observed with 1-benzyloxymethyl-1-vinyloxirane with a proper catalytic activity. The elaboration of the reaction conditions and work-up procedures enabled a preparative-scale kinetic resolution, to give (R)-2-benzyloxymethyl-3-butene-1,2-diol and its antipodal (R)-epoxide in high ees.     

Force fields of allylamine conformers as studied by an ab initio calculation and infrared spectroscopy

The quadratic force constants of the five possible conformers of allylamine were calculated by an ab initio MC method. The infrared spectra of this molecule in the gas phase were remeasured and analyzed on the basis of the calculated vibrational frequencies. A potential energy surface with respect to the skeletal torsions was also calculated. The relative abundances of the S⁺G⁺, ST, CT, CG, and S⁺G^? conformers, predicted to be 44:32:16:7:1 at room temperature, are consistent with the experimental data.