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The present study shows that a hydrogen bond between the OH group and the fluorine atom is not involved in the (1h)J(FH) spin-spin coupling transmission either for 4-bromo-2-fluorophenol or 2-fluorophenol. In fact, according to a quantum theory of atoms in molecules analysis, no bond critical point is found between O-H and F moieties. The nature of the transmission mechanism of the Fermi contact term of the (1h)J(FH) spin-spin coupling is studied by analyzing canonical molecular orbitals (see J. Phys. Chem. A 2010, 114, 1044), and it is observed that virtual orbitals play only a quite minor role in its transmission. This is typical of a Fermi contact term transmitted mainly through exchange interactions owing to the overlap of proximate electronic clouds; therefore, it is suggested to identify them as (nTS)J(FH) coupling where n stands for the number of formal bonds separating the coupling nuclei. In the cases studied in this work is n = 4. Results presented in this work could provide an interesting rationalization for different experimental signs known in the current literature for proximate J(FH) couplings.

OBJECTIVEIn obesity, an increased macrophage infiltration in adipose tissue occurs, contributing to low-grade inflammation and insulin resistance. Epidermal growth factor receptor (EGFR) mediates both chemotaxis and proliferation in monocytes and macrophages. However, the role of EGFR inhibitors in this subclinical inflammation has not yet been investigated. We investigated, herein, in vivo efficacy and associated molecular mechanisms by which PD153035, an EGFR tyrosine kinase inhibitor, improved diabetes control and insulin action.RESEARCH DESIGN AND METHODSThe effect of PD153035 was investigated on insulin sensitivity, insulin signaling, and c-Jun NH2-terminal kinase (JNK) and nuclear factor (NF)-κB activity in tissues of high-fat diet (HFD)-fed mice and also on infiltration and the activation state of adipose tissue macrophages (ATMs) in these mice.RESULTSPD153035 treatment for 1 day decreased the protein expression of inducible nitric oxide synthase, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in the stroma vascular fraction, suggesting that this drug reduces the M1 proinflammatory state in ATMs, as an initial effect, in turn reducing the circulating levels of TNF-α and IL-6, and initiating an improvement in insulin signaling and sensitivity. After 14 days of drug administration, there was a marked improvement in glucose tolerance; a reduction in insulin resistance; a reduction in macrophage infiltration in adipose tissue and in TNF-α, IL-6, and free fatty acids; accompanied by an improvement in insulin signaling in liver, muscle, and adipose tissue; and also a decrease in insulin receptor substrate-1 Ser307 phosphorylation in JNK and inhibitor of NF-κB kinase (IKKβ) activation in these tissues.CONCLUSIONSTreatment with PD153035 improves glucose tolerance, insulin sensitivity, and signaling and reduces subclinical inflammation in HFD-fed mice.

Full geometry optimizations were carried out at the HF/6-31G** and B3LYP/6-31G** levels for methylcyclohexane, 2-, 3-, and 4-methyltetrahydropyran, 2-, 3-, and 4-methylpiperidine, 2-, 3-, and 4-methylthiane, 2-, 4-, and 5-methyl-1,3-dioxane, and 2-, 4-, and 5-methyl-1,3-dithiane and also for S-methyl thianium. Constrained geometry optimizations were carried out for methylcyclohexane, 2-methyl-1,3-dioxane, and the axial conformers of 2- and 3-methyltetrahydropyran and 2- and 3-methylpiperidine. The steric repulsion model, which is believed to account for the conformational energies of the cited compounds, was tested by stretching bonds and bending angles so that the axial methyl group is either forced to approach the ring gamma methylenes or get farther away from them. The calculated energies show that the energy costs of these perturbations are not dependent on the distances between the axial methyl group and the ring gamma methylenes and are not dependent on whether the methyl is axial or equatorial. It is shown that, besides the steric repulsion model, the conformational energies of the compounds studied are dictated by hyperconjugative interactions involving mainly the methine hydrogen. The C[bond]C lengths of the axial and equatorial conformers of methylcyclohexane are shown to be related to hyperconjugation.

Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N(2) and CH(4) and includes traces of many simple organic compounds. This atmosphere also partly consists of haze and aerosol particles which during the last 4.5 gigayears have been processed by electric discharges, ions, and ionizing photons, being slowly deposited over the Titan surface. In this work, we investigate the possible effects produced by soft X-rays (and secondary electrons) on Titan aerosol analogs in an attempt to simulate some prebiotic photochemistry. The experiments have been performed inside a high vacuum chamber coupled to the soft X-ray spectroscopy beamline at the Brazilian Synchrotron Light Source, Campinas, Brazil. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The infrared spectra have presented several organic molecules, including nitriles and aromatic CN compounds. After the irradiation, the brownish-orange organic residue (tholin) was analyzed ex-situ by gas chromatographic (GC/MS) and nuclear magnetic resonance ((1)H NMR) techniques, revealing the presence of adenine (C(5)H(5)N(5)), one of the constituents of the DNA molecule. This confirms previous results which showed that the organic chemistry on the Titan surface can be very complex and extremely rich in prebiotic compounds. Molecules like these on the early Earth have found a place to allow life (as we know) to flourish.