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A systematic structural study on the intercalation of the radical cation 2-(4-N-methylpyridinium)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl-3-N-oxide (p-MPYNN) into a synthetic fluoromica clay named Somasif® ME 100, Na2x Mg3.0−x Si4O10(F y OH1−y )2 (x = 0.33, y = 0.98), has been carried out. The guest–host interactions in these intercalation compounds have been characterized by X-ray powder diffraction and solid-state NMR of the constituent nuclei (23Na, 19F, 27Al and 29Si) of the Somasif lattice. The intercalation process can be quantitatively monitored using 23Na MAS-NMR. As a function of radical ion loading, different kinds of stacking arrangements can be realized, which modify the intermolecular interactions between the electron spins of the guest species, as probed by electron spin resonance (EPR) and 1H solid state nuclear magnetic resonance (NMR). The results are discussed in relation to previous literature data on similar systems.

An efficient Pd-catalyzed arylation of alkylpyridine based on the pyridinium activation strategy has been developed for synthesis of mixed aryl alkylpyridines. It was found that (1) the N-methyl group in the pyridinium salts acted as a transient activator and could be automatically departed after the reaction, (2) CuBr was an indispensable additive for achieving the C6-selective arylation, (3) the α-branched alkyl chain on the alkylpyridine greatly increased the yield of the product. Deuterium labelling experiment revealed that in the case of the α-branched alkylpyridine, the presence of CuBr completely inhibited the H/D exchange at the benzylic position and thus enabled the selective arylation at the C6 position. This protocol demonstrates a broad substrate scope, and with respect to both the aryl iodides and the α-branched alkylpyridine, the desired mixed aryl alkylpyridines were obtained in generally good to excellent yields.

Although coffee consumption has been historically associated with negative health outcomes, recent evidence suggests a lower risk of metabolic syndrome, obesity and diabetes among regular coffee drinkers. Among the plethora of minor organic compounds assessed as potential mediators of coffee health benefits, trigonelline and its pyrolysis product N-methylpyridinium (NMP) were preliminary shown to promote glucose uptake and exert anti-adipogenic properties. Against this background, we aimed at characterizing the effects of trigonelline and NMP in inflamed and dysfunctional human adipocytes. Human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were treated with NMP or, for comparison, trigonelline, for 5 h before stimulation with tumor necrosis factor (TNF)-α. NMP at concentrations as low as 1 µmol/L reduced the stimulated expression of several pro-inflammatory mediators, including C-C Motif chemokine ligand (CCL)-2, C-X-C Motif chemokine ligand (CXCL)-10, and intercellular adhesion Molecule (ICAM)-1, but left the induction of prostaglandin G/H synthase (PTGS)2, interleukin (IL)-1β, and colony stimulating factor (CSF)1 unaffected. Furthermore, NMP restored the downregulated expression of adiponectin (ADIPOQ). These effects were functionally associated with downregulation of the adhesion of monocytes to inflamed adipocytes. Under the same conditions, NMP also reversed the TNF-α-mediated suppression of insulin-stimulated Ser473 Akt phosphorylation and attenuated the induction of TNF-α-stimulated lipolysis restoring cell fat content. In an attempt to preliminarily explore the underlying mechanisms of its action, we show that NMP restores the expression of the master regulator of adipocyte differentiation peroxisome proliferator-activated receptor (PPAR)γ and downregulates activation of the pro-inflammatory mitogen-activated protein jun N-terminal kinase (JNK). In conclusion, NMP reduces adipose dysfunction in pro-inflammatory activated adipocytes. These data suggest that bioactive NMP in coffee may improve the inflammatory and dysmetabolic milieu associated with obesity.

Scope: Coffee consumption is widely recognized to improve the antioxidant status. We hypothesized a dark-roast coffee to reduce plasma oxidized LDL (oxLDL) and to improve alpha-tocopherol concentrations. Methods and results: After a 4 week, coffee-free run-in period, 86 healthy, randomized volunteers completed either a control (CTRL) or coffee (COFF) intervention in which either 750 mL water (CTRL) or coffee (COFF) were consumed daily for 8 weeks. Blood samples were taken at the begin and after the intervention. Mean changes in oxidized LDL concentrations after coffee consumption (−0.47 ± 15.4 U/L) differed from those of the CTRL-G (5.69 ± 18.8 U/L, p

cited By 0; International audience; The physicochemical and electrochemical properties, including electropolymerization, of the water soluble 2,9(10),16(17),23(24)-tetra-(2-mercapto-N-methylpyridinium)phthalocyaninato zinc(II), 1, have been studied in the present work. While this phthalocyanine is soluble in DMSO as the monomeric species, it exists as very stable dimers in aqueous solutions. These dimers break down into monomers upon addition of an anionic surfactant, sodium dodecylsulphate (SDS). The aqueous solutions of 1 have been studied by rotating disc electrode, cyclic and square-wave voltammetries, and spectroelectrochemistry. Upon reduction, an electroactive film of the zinc(II) phthalocyanine is formed at the surface of the electrode, due to the reduction of the N-methylpyridinium groups which induces the formation of bispyridines and therefore the deposition of an insoluble polymer. © 2016 Elsevier Ltd

Quantitative analysis of the bioactives trigonelline (1), N-methylpyridinium (2), caffeine (3), and caffeoylquinic acids (4) in a large set of roasted Arabica (total sample size n = 113) and Robusta coffees (total sample size n = 38) revealed that the concentrations of 1 and 4 significantly correlated with the roasting color (P0.001, two tailed), whereas that of 2 significantly correlated inversely with the color (P0.001, two tailed). As dark-roasted coffees were rich in N-methylpyridinium whereas light-roasted coffees were rich in trigonelline and caffeoylquinic acids, manufacturing of roast coffees rich in all four bioactives would therefore necessitate blending of two or even more coffees of different roasting colors. Additional experiments on the migration rates during coffee brewing showed that all four bioactives were nearly quantitatively extracted in the brew (90%) when a water volume/coffee powder ratio of16 was used.

A convenient solvent less cyclocondensation from thiosemicarbazone of benzofuranone and chloroacetic acid using an ionic liquid, N-methylpyridinium tosylate for obtaining novel 4-thiazolidinones in excellent yields is reported. Also, the green expedient synthesis of new 2,4-disubstituted thiazoles under grinding condition from phenacyl bromides and thiosemicarbazide derivatives in quantitative yields is reported.

The substituent effect on structure and surface activity of mono- and disubstituted N-methylpyridinium salts was investigated by means of Raman, infrared and surface-enhanced Raman spectroscopy (SERS). The significant differences observed in Raman and infrared spectra have been correlated with marker bands assigned to in-plane and out-of-plane vibrations, respectively. This vibrational analysis, complemented by quantum chemical calculations (B3LYP/6-311++G(d,p)) was a basis for investigation of the surface activity of the studied compounds. Significant differences in their SERS spectra related to the enhancement mechanism and adsorbate orientation have been observed and analyzed. Copyright © 2012 John Wiley & Sons, Ltd. Supporting information may be found in the online version of this article.

Following an application from Tchibo GmbH, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Germany, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to coffee C21 and reduction of DNA damage by decreasing spontaneous DNA strand breaks. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. Coffee C21, a coffee standardised by its content of caffeoylquinic acids, trigonelline and N‐methylpyridinium (NMP), which is the subject of the health claim, is sufficiently characterised. Reduction of DNA damage by decreasing spontaneous DNA strand breaks is a beneficial physiological effect. In weighing the evidence, the Panel took into account that one human intervention study showed that daily consumption of coffee C21 (750 ml/day) for four weeks decreased spontaneous DNA strand breaks in habitual coffee drinkers after coffee withdrawal over the previous four weeks, but that no other human studies in which these results have been replicated were provided, and that no evidence was provided for a mechanism by which coffee (including coffee C21) could exert the claimed effect. The Panel concludes that a cause and effect relationship has not been established between the consumption of coffee C21, a coffee standardised by its content of caffeoylquinic acids, trigonelline and NMP, and a reduction of DNA damage by decreasing spontaneous DNA strand breaks.

The reaction of (PyH)2[MoOCl5] with pyridine and methanol in the presence of CoCl2·6H2O and H2C2O4·2H2O at 130 °C under solvatothermal conditions afforded (Me–NC5H5)4n[Mo8O26]n 1. The structure consists of infinite molybdenum oxide chains bearing a negative charge and N-methylpyridinium cations. Eight {MoO6} octahedra are arranged in an edge-sharing manner to form compact octamolybdate subunits which are connected through pairs of Mo–O–Mo bridges into extended one-dimensional arrays.

In the crystal of the title molecular salt, C7H7N2+·ClO4−, the components are linked by C—H...O and C—H...N interactions, generating zigzag chains running parallel to [100].

A new dye trans-4-[p-(N-hydroxyethyl-N-ethylamino)styryl]-N-methylpyridinium p-toluene sulfonate (HEASPS) has been synthesized. The two-photon absorption (TPA), TPA-induced frequency up-conversion emission, and two-photon pumped (TPP) frequency up-converted lasing properties of this new dye were experimentally studied. This new dye has a TPA cross-section of σ2 = 4.7 × 10-48 cm4 · s/photon at 1064 nm, but exhibits a high lasing efficiency. The net conversion efficiency from the absorbed 1064 nm pump pulse energy to the 625 nm up-converted lasing energy is 3.6% at the pump energy level of 4 mJ.

The inclusion behaviour of a new water-soluble sulfonated calix[4]resorcinarene towards alkylammonium and N-methylpyridinium cations has been investigated on the basis of 1H NMR spectroscopy and pH-potentiometry data. The inclusion of the N-methylpyridinium cation has been found to be dependent on pH with the preferable inclusion of the methyl substituent in alkaline and the aromatic ring in neutral aqueous media.

The title compound, C7H7N2+·Br−, forms a layered solid with each cation forming three strong and one weaker C—H⋯Br hydrogen bonds within the layer. All atoms except two of the methyl H atoms lie on a mirror plane.

Scope: In order to validate the in vivo function of putatively healthy molecules in foods, human intervention studies are required. As the subject’s compliance concerning intake or abstinence of a given food is considered mandatory to be monitored by biomarkers, the objective was to identify analytical markers for coffee consumption. Methods and results: Urine samples collected from coffee drinkers were compared with those of non-coffee drinkers using hydrophilic liquid interaction chromatography (HILIC)/time-offlight mass spectrometry-based metabolite profiling. Two urinary molecules, found to be contributing most to the dissimilarities between both groups, were identified as N-methylpyridinium (NMP) and trigonelline and their suitability as coffee-specific biomarkers was validated by means of a coffee intervention study. After the volunteers (five females and four males) consumed a single dose of coffee, morning urine was collected for 10 days while staying abstinent from any coffee. HILIC-MS/MS-stable isotope dilution analysis (SIDA) revealed elevated urinary concentrations of trigonelline and NMP for up to 48 (p 5 0.001) and 72 h (p 5 0.002), respectively, after coffee consumption when compared with non-coffee drinkers. Conclusion: Analysis of urinary NMP allows to check for coffee consumption within a period of 3 days and is proposed as a dietary biomarker which might be used as an analytical probe to control compliance in human intervention studies on coffee.

Photoinduced electron transfer (ET) is studied in a series of novel molecules containing a dimethoxynaphthalene (DMN) donor and either a pyridine (P) or N-methylpyridinium (P-Me + ) acceptor covalently linked via a rigid nonbornalogous bridge ( n sigma bonds in length). ET rates of the order of 10 10 s −1 were measured for the DMN- n -P-Me + series ( n = 4, 6), while no appreciable ET was observed for the DMN- n -P compounds. Electronic and nuclear factors are discussed and the results rationalized in terms of Marcus—Hush and non-adiabatic ET theories.

The photoreactions of 3-methoxycarbonyl-N-methylpyridinium perchlorate (1a) and 3-carbamoyl-N-methylpyridinium perchlorate (1b) under N2 give the products methylated at the 6- and 4-positions in methanol. Under O2, the photoreaction of 1a is drastically changed to give a product methoxylated at the 2-position and hydroxylated at the 5-position simultaneously. This compound is unstable and changes to 5-hydroxy-3-methoxycarbonyl-N-methyl-2-pyridone (5a). Only one atom of O2 is incorporated in 5a. The photoreaction of 1b is completely inhibited by O2.

Isomeric bis-terpyridine complexes of iridium(III) incorporating meta- or para-N-methylpyridyl substituents at the terpyridine 4′-position display long-lived luminescence in solution which is quenched by chloride ions to very different extents.

The vibrational spectra of N -methylpyridinium iodide and three of its selectively deuterated derivatives have been recorded in the crystalline as w

Dithienylethenes having a pyridinium cation at one and both thiophene rings were synthesized. The derivatives with two pyridinium cation showed the cyclization quantum yield as high as 0.71, which is much larger than the values of the monocation derivative and the neutral form. This can be explained by the conformation of the open-ring isomer of the diarylethenes.

Three new N-methyl pyridinium alkaloids, platisidines A-C (1-3), were isolated from an Okinawan marine sponge of the genus Plakortis, and the structures were elucidated from spectroscopic data. The structures of platisidines A-C (1-3) were elucidated to be N-methyl nicotinic acid derivatives with a n-hexadecanoyl chain. Platisidines A-C (1-3) showed inhibitory activity against acetylcholinesterase.

La reaction du nitromethane avec des chlorures de pyridinium dans l'ammoniac liquide conduit a des [nitromethylene-4 dihydro-1,4] pyridines

N-Methylpyridinium-diiodocuprate(I), C6H8NCuI2 and dimethyl(3-dimethylamino-2-aza-2-propenyliden)ammonium-diiodocuprate(I), C6H14N3CuI2, are obtained by reacting Cu with C6H8NI3 or C6H14N3I3 in acetone. Both compounds are built up by the organic cations and chains of edge sharing tetrahedra1 ∞[Cul4/2-]. The iodocuprate(I) anions are in intimate contact with the cations via intermolecular I···C interactions. Though nearly the same average Cu-I distance of 267.2 or 268.2 pm was found for both iodocuprate(I) anions there are different Cu-Cu distances (301-354 pm).

The passage of 2-hydroxyiminomethyl- N -methylpyridinium methanesulfonate (P2S) to the perfused cerebral spaces of pregnant does and to their fetuses has been studied. The oxime did not penetrate into the fetus after intravenous injection of 30 mg/kg though it did after 60 mg/kg or continuous slow infusion of 2.5 mg/kg/min during 45 minutes. In all cases P2S was found in the perfusate of cerebral spaces. In animals intoxicated with tetraethyl pyrophosphate, the maternal blood cholinesterase was rapidly reactivated after injection of 30 mg/kg of P2S, but both brain and blood cholinesterase activity of the fetuses stayed reduced. Administration of 60 mg/kg reactivated the enzyme also in fetuses. It is suggested that in cases of organophosphate poisoning in pregnant females, high doses of P2S should be administered in order to reach the fetus. Continuous slow infusion of the oxime appears to be the method of choice, as it also maintains a satisfactory constant plasma level.

N-methylpyridinium-2-nitrile has been identified in urine from rats and human beings treated with N-methylpyridinium-2-aldoxime. When injected into rats the nitrile is partially converted to inorganic thiocyanate and a metabolite possibly identical with metabolite X found in urine from oxime-treated animals. The nitrile was somewhat more toxic than the oxime.

2-Hydroxyiminomethyl-N-methylpyridinium methanesulphonate (P2S) is prepared by boiling pyridine-2-aldoxime with methyl methanesulphonate in benzene. It can be estimated both in water and in biological materials by measuring its ultra-vìolet absorption in alkaline solution. In aqueous solution it is slowly decomposed by heat or prolonged storage with some cyanide ion formation. The stability varies with pH, being optimal at pH 4–5. P2S can be satisfactorily sterilised by filtration through a “millipore” filter.

N-methylpyridinium-2-aldoxime methanesulphonate (P2S) was administered to rats and the urinary excretion of thiocyanate was determined by different methods. In addition to a small increase in thiocyanate excretion a metabolite was found which interfered with one of the test methods. It was concluded that formation of cyanide could not account for the toxicity of the oxime. Similar experiments on human beings showed no significant increase in thiocyanate excretion, but small amounts of an unknown metabolite were formed.

The soluble methanesulphonate of the oxime 2-hydroxyiminomethyl-N-methylpyridinium (P2S) has been used to treat animals poisoned with sarin or ethyl pyrophosphate. The effect of the size of the dose, and its time of administration in relation to poisoning, have been examined. This oxime is very efficient in conjunction with atropine when given either before or after poisoning. About 30 mg./kg. seems to be the optimum therapeutic dose of the methanesulphonate. The significance of this optimum is discussed in relation to the treatment of accidental poisoning by organophosphate insecticides in man.

N-Methyl-pyridinium-3-oxid (I) reagiert bei der Bestrahlung in Gegenwart von Sauerstoff zum Furanon (II) und zu N-Methyl-maleinimid (III),in Athanol werden die isomeren Ester (IV), das Pyridon (V) und das Oxamat (VI) erhalten.

Oxidative imination of pyridinium salts such as (I) with KMnO4/liquid ammonia proceeds via amino derivatives such as (II).

N-methylpyridinium-2-aldoxime iodide (PAM), labelled with 14 C on the methyl group, was injected into rats and the excretion of the isotope in the urine was followed. Most of the radioactivity was excreted as unchanged PAM, but paper chromatography also demonstrated the formation of a number of metabolites, among which N-methylpyridinium-2-nitrile, N-methylpyridinium-2-carboxylic acid (homarine) and N-methyl-2-pyridone were identified.

A new reagent, 1-(N-methylpyridinium-4-yl-azo)-4-(4-diethylaminophenylazo)naphthalene iodide, can react with sodium 4-dodecylbenzenesulfonate to show a color change in an aqueous phase in the presence of iodide ion. The calibration graph is straight line up to 1.2×10−5 M (1 M=1 mol dm−3); e=3.25×104 1 mol−1 cm−1 at 580 nm.

The chemical shifts of the N-methyl group in a series of 2-, 3- and 4-substituted N-methylpyridinium salts have been measured in DMSO solution. The shift is primarily affected by resonance interaction between the substituent and aza group, and the results suggest that the resonance effect from a 2-substituent is at least as great as from the corresponding 4-substituent.

Kinetics of the reactions of halogeno-, methoxy-, methylthio-, and methylsulphonyl-substituted N-methylpyridinium salts with hydroxide ions have been determined. The salts with the leaving group in the 2-position were the most reactive: e.g. the k2 values for 2-, 3-, and 4-methoxypyridine methiodides at 20° were 2·9 × 10–2, 5·0 × 10–9, and 7·6 × 10–4 l mol–1 s–1, respectively. Quaternisation of 4-methylsulphonylpyridine by methylation increased its reactivity to hydroxide ions by 7·3 × 108-fold at 20°, owing to a decrease in energy of activation of 7·1 kcal mol–1, and an increase in log A 3·5 units.U.v. and 1H n.m.r. spectra are recorded and discussed.