Molecular Structures of Isomeric Ortho, Meta, and Para Bromo-Substituted α-Methylsulfonyl-α-diethoxyphosphoryl Acetophenones by X-ray and DFT Molecular Orbital Calculations.

The X-ray single crystal analysis of isomeric ortho, meta, and para bromo-substituted α-methylsulfonyl-α-diethoxyphosphoryl acetophenones showed that this class of compound adopts synclinal (gauche) conformations for both [-P(O)(OEt)2] and [-S(O)2Me] groups, with respect to the carbonyl functional group. The phosphonate, sulfonyl, and carbonyl functional groups are joined through an intramolecular network of attractive interactions, as detected by molecular orbital calculations at the M06-2X/6-31G(d,p) level. These interactions are responsible for the more stable conformations in the gas phase, which also persist in the solid-state structures. The main structural distinction in the title compounds relates to the torsion angle of the aryl group (with respect to the carbonyl group), which gives rise to different interactions in the crystal packing, due to the different positions of the Br atom.

Complete assignment of 1H and 13C NMR spectra of alpha-phenylsulfinyl-N-methoxy-N-methylpropionamide and some p-substituted derivatives.

The complete assignment of the (1)H and (13)C NMR spectra of the diastereomeric pairs of some alpha-arylsulfinyl-substituted N-methoxy-N-methylpropionamides with the substituents methoxy, methyl, chloro, nitro is reported.

Substituent effects in the 13C NMR chemical shifts of alpha-mono-substituted acetonitriles.

13C chemical shifts empirical calculations, through a very simple additivity relationship, for the alpha-methylene carbon of some alpha-mono-substituted acetonitriles, Y-CH(2)-CN (Y=H, F, Cl, Br, I, OMe, OEt, SMe, SEt, NMe(2), NEt(2), Me and Et), lead to similar, or even better, results in comparison to the reported values obtained through Quantum Mechanics methods. The observed deviations, for some substituents, are very similar for both approaches. This divergence between experimental and calculated, either empirically or theoretically, values are smaller than for the corresponding acetones, amides, acetic acids and methyl esters, which had been named non-additivity effects (or intramolecular interaction chemical shifts, ICS) and attributed to some orbital interactions. Here, these orbital interactions do not seem to be the main reason for the non-additivity effects in the empirical calculations, which must be due solely to the magnetic anisotropy of the heavy atom present in the substituent. These deviations, which were also observed in the theoretical calculations, were attributed in that case to the non-inclusion of relativistic effects and spin-orbit coupling in the Hamiltonian. Some divergence is also observed for the cyano carbon chemical shifts, probably due to the same reasons.

Nitric oxide: Protein tyrosine phosphorylation and protein S-nitrosylation in cancer.

Cancer is a worldwide health problem leading to a high incidence of morbidity and mortality. Malignant transformation can occur by expression of oncogenes, over-expression and deregulated activation of proto-oncogenes, and inactivation of tumor suppressor genes. These cellular actions occur through stimulation of oncogenic signaling pathways. Nitric oxide (NO) can induce genetic changes in cells and its intracellular generation can lead to tumor formation and progression. It can also promote anti-tumor activities. The pro- and anti-tumor activities of NO are dependent on its intracellular concentration, cell compartmentalization, and cell sensitivity. NO affects a number of oncogenic signaling pathways. This review focuses on two oncogenic signaling pathways: NO-EGFR-Src-FAK and NO-Ras-EGFR-ERK1/2 MAP kinases. In these pathways, low to intermediate concentrations of NO/S-nitrosothiols (RSNOs) stimulate oncogenic signaling, while high concentrations of NO/RSNO stimulate anti-oncogenic signaling. Increasing knowledge on pro- and anti-tumorigenic activities of NO and related reactive species such as RSNOs has fostered the research and synthesis of novel NO-based chemotherapeutic agents. RSNOs, effective as NO donors and trans-nitrosylating agents under appropriate conditions, may operate as potential chemotherapeutic agents.

Complete assignment of 1H and 13C NMR spectra of some alpha-arylthio and alpha-arylsulfonyl substituted N-methoxy-N-methyl propionamides.

The complete assignments of the 1H and 13C NMR spectra of the some alpha-arylthio and alpha-arylsulfonyl substituted N-methoxy-N-methyl propionamides, bearing methoxy, methyl, chloro, and nitro as substituents at the phenyl ring are reported.