Proteomic Analysis of Sarcoplasmic Peptides of Two Related Fish Species for Food Authentication

Detection of species-specific sarcoplasmic peptides can be used as proteomic markers for fish food authentication and identification of species of origin in processed products. In the present study, proteomics technology was employed for differential characterization of sarcoplasmic peptides of two closely related fish species, Sperata seenghala and Sperata aor. Species-specific peptides were searched in white muscle extracts of the two species for identification of unique peptides that might aid in differentiation of the species, under two-dimensional gel electrophoresis platform. A total of 19 proteins were identified by combined matrix-assisted laser desorption ionization time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry, of which nine and two proteins were found to be unique to S. seenghala and S. aor, respectively. One of the proteins, triosephosphate isomerase (TPI) was found to have three isoforms, out of which two were specific to S. aor, and one was specific to S. seenghala. All the three isoforms of TPI were present in the mixed samples of raw protein extracts of S. seenghala and S. aor, an observation that can be exploited to differentiate between the species and detection of deceptive practices of fraudulent substitution of commercially valuable fish species with inferior ones and differential characterization between closely related fish species.     

Synthetic Applications of the Baylis–Hillman Reaction: Simple and Convenient Synthesis of Five Important Insect Pheromones

A simple and convenient synthesis of five important insect pheromones by means of Baylis–Hillman adducts is described, i.e., of (2E,4S)‐2,4‐dimethylhex‐2‐enoic acid ( 1 ), a mandibular‐gland secretion of the male carpenter ant in the genus Camponotus, of (+)‐(S)‐manicone ( 2 ) and (+)‐(S)‐normanicone ( 3 ), two mandibular‐gland constituents of Manica ants, and of (+)‐dominicalure‐I ( 6 ) and (+)‐dominicalure‐II ( 7 ), two aggregation pheromones of the lesser grain borer Rhyzopertha dominica (F). For the first time, the potential of the Baylis–Hillman chemistry for the stereoselective synthesis of trisubstituted olefins was successfully applied to the synthesis of these pheromone compounds.     

Evaluation and comparison of global scalar properties for the simultaneous interaction of ionic liquids with thiophene and pyridine

Ab initio studies were carried out with mixtures containing ionic liquid with thiophene and pyridine for studying the simultaneous interaction. Global scalar properties such as HOMO/LUMO energies, HOMO–LUMO energy gap, chemical hardness, chemical potential, electronegativity, global hardness, global softness and electrophilicity index were determined for clusters containing ionic liquids with thiophene and pyridine. Ionic liquids containing: 1-butyl-3-methylpyrrolidinium [BUMPYR], 1-benzyl-3-methyimidazolioum [BeMIM] and 1-butyl-3-methylpyridinium [BUMPY] cations combined with inorganic anions containing fluorine ([BF₄] and [PF₆]) were studied in this work. [BeMIM][BF₄] (1-benzyl-3-methyimidazolioum tetrafluoroborate) with a HOMO–LUMO energy gap of 0.1882 Hartrees was found to be the most effective IL. Further a ranking based on all the mentioned scalar parameters also pointed out [BeMIM][BF₄] to be the most desirable IL. The overall ranking after taking into considerations all factors followed: [BeMIM][BF₄] > [BUMPYR][BF₄] > [BUMPY][PF₆] > [BUMPY][BF₄] > [BUMPYR][PF₆]. To validate the findings, infinite dilution activity coefficients were predicted using the quantum chemical based COSMO-RS methodology which gave the same trend as observed using scalar properties.     

Photophysical properties of the 8-phenyl analogue of PM567: A theoretical rationalization

The absorption and emission spectroscopic investigations of the C-8-phenyl substituted analogue of the pyrromethene dye PM567 in various polar, non-polar as well as protic and aprotic solvents are reported. The solvatochromic shifts of the spectral bands were studied in a multitude of polar, non-polar and protic, aprotic solvents followed by a multilinear regression in which several solvent parameters were simultaneously analysed. Comparison of the experimental results with those obtained by gas phase ab initio computation with CIS, TD-HF and TD-DFT theories using 6-31G* basis set reveal an overestimation of the experimentally measured excitation parameters by all these theoretical models. However, the trends in the experimental results agree with those calculated theoretically.     

Cholesterol Sequestration from Caveolae/Lipid Rafts Enhances Cationic Liposome-Mediated Nucleic Acid Delivery into Endothelial Cells

Delivering nucleic acids into the endothelium has great potential in treating vascular diseases. However, endothelial cells, which line the vasculature, are considered as sensitive in nature and hard to transfect. Low transfection efficacies in endothelial cells limit their potential therapeutic applications. Towards improving the transfection efficiency, we made an effort to understand the internalization of lipoplexes into the cells, which is the first and most critical step in nucleic acid transfections. In this study, we demonstrated that the transient modulation of caveolae/lipid rafts mediated endocytosis with the cholesterol-sequestrating agents, nystatin, filipin III, and siRNA against Cav-1, which significantly increased the transfection properties of cationic lipid-(2-hydroxy-N-methyl-N,N-bis(2-tetradecanamidoethyl)ethanaminium chloride), namely, amide liposomes in combination with 1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) (AD Liposomes) in liver sinusoidal endothelial cells (SK-Hep1). In particular, nystatin was found to be highly effective with 2–3-fold enhanced transfection efficacy when compared with amide liposomes in combination with Cholesterol (AC), by switching lipoplex internalization predominantly through clathrin-mediated endocytosis and macropinocytosis.     

Poly‐Schiff bases. V. Synthesis and characterization of novel soluble fluorine‐containing polyether azomethines

A new dialdehyde monomer, 4,4′‐(hexafluoroisopropylidine) bis(p‐phenoxy) benzaldehyde, was prepared; it led to a number of novel poly‐Schiff bases in reactions with different diamines, such as 4,4′‐diaminidiphenyl ether, 4,4′‐(isopropylidine) bis(p‐phenoxy) dianiline, 4,4′‐(hexafluoroisopropylidine) bis(p‐phenoxy) dianiline, and benzidine. The polymers were characterized with viscosity measurements, nitrogen analyses, and IR and ¹H NMR spectroscopy. These poly‐Schiff bases showed good thermal stability up to 491 °C for 10% weight loss in thermogravimetric analysis under air and high glass‐transition temperatures up to 215 °C in differential scanning calorimetry. These polymers were soluble in a wide range of organic solvents, such as CHCl₃, dimethylformamide (DMF), dimethyl sulfoxide, and 1‐methyl‐2‐pyrrolidon (NMP), and were insoluble in toluene and acetone. Thin films of these polymers cast from DMF exhibited tensile strengths up to 38 MPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 383–388, 2001     

Room temperature solution studies of complexation between o-chloranil and a series of anilines by spectrophotometric method.

Electron donor-acceptor (EDA) complex formation between o-chloranil and a series of anilines has been studied in CCl4 medium. In all the cases, EDA complexes are formed instantaneously on mixing the donor and acceptor solutions. N,N-dimethylaniline and N,N-dimethyl-p-toluidine form stable EDA complexes with o-chloranil while the other complexes decay slowly into secondary products. The kinetics of all these reactions has been studied by UV-VIS absorption spectrophotometric method and the rate constants of the reactions and formation constants of the EDA complexes have been determined. The charge transfer (CT) transition energies of the complexes are found to change systematically with change in the number and position of the methyl groups in the donor molecules (methylanilines). From an analysis of this variation, the electron affinity of o-chloranil has been found to be 2.54 eV. A perturbational inductive effect Hückel parameter hMe has been found from this trend and the value obtained (-0.27) is very close to that (-0.3) obtained by Lepley (J. Am. Chem. Soc., 86 (1964) 2545) from a study of tetracyano ethylene (TCNE)-methylbenzene complexes.     

Microwave‐assisted synthesis,spectroscopy and biological aspects of binuclear titanocene chelates of isatin‐2,3‐bis(thiosemicarbazones)

The reactions of bis(cyclopentadienyl)titanium(IV) chloride with a new class of bis(thiosemicarbazones) (H₂L), derived by condensing isatin with different N(4)‐substituted thiosemicarbazides, have been studied both by a conventional stirring method and also using microwave technology. Binuclear products of type [{(η⁵‐C₅H₅)₂TiCl} ₂(L)] have been isolated in both cases. Tentative structural conclusions are drawn for the reaction products based upon analysis, electrical conductance, magnetic moment and spectral (UV‐visible, IR, ¹H NMR and ¹³C NMR) data. FAB mass spectra of these compounds were also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the ligands and complexes against various fungal, viral and bacterial strains. Copyright © 2008 John Wiley & Sons, Ltd.     

Imaging elastic property of surfaces at nanoscale using atomic force microscope

We present a simple technique to characterize and image the distribution of local elastic property using ultrasonic atomic force microscope (UAFM). We interpret the UAFM images using simple arguments. We have demonstrated the capability of the UAFM technique to image the distribution of the local elastic property of the sample surface and semi-quantitatively map the local stiffness of the sample surface using a few selected samples. The local stiffness of the sample surface was obtained by measuring the changes in the frequency of contact resonance peak values and could verify the same using force-distance measurement at the same regions on the sample surface.     

Theoretical spectroscopic studies of InI and InI+

Relativistic configuration interaction calculations are carried out to study the electronic structure and spectroscopic properties of InI and InI⁺. Potential energy curves of the ground and a number of low‐lying states are constructed. Spectroscopic parameters of the bound states of both species are computed and compared with the experimental and other theoretical data. Effects of spin‐orbit coupling on the spectroscopic properties are studied. Because of the presence of the heavy atoms the effect is large. The spin‐orbit splitting of the ground state (X²Π) of InI⁺ is more than 8350 cm^?1. As a result of the strong spin‐orbit interaction between X²Π and A²Σ⁺ of InI⁺, the potential energy curve of A²Σ becomes repulsive. Radiative lifetimes for the spin‐forbidden transitions such as A³Π?X¹Σ and B³Π₁ ?X¹Σ of InI and spin‐allowed transitions such as B²Σ⁺?A²Σ⁺, C²Π?A²Σ⁺, and B²Σ⁺?X²Π are calculated. Vertical and adiabatic ionization energies of InI and the electric dipole moments of both the neutral and ionic species are estimated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010