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The electrooxidation of linear saturated aliphatic alcohols from C1 to C8 on gold in alkaline media has been studied by cyclic voltammetry and with an electrochemical quartz crystal microbalance. The current density of alcohol oxidation very markedly increased and, correspondingly, the onset potential decreased, with increasing chain length, that is, with initially slightly increasing, and then constant, pKa. We attribute this oxidazability increase with chain length to the increasing hydrophobicity of the alcohol. Effectively, a molecular dynamics simulation of the hydration of alcohols and alcoholates shows that the hydrophobicity of the alcohols increases with increasing chain length. The higher activity of gold for the oxidation of organic, and also inorganic (CO), compounds in alkaline media is well known, and should be due to an activation of the gold surface by OH adsorption, and not to a change of the compounds themselves, the (majority) neutral alcohol being the oxidized species both in acid and alkaline media. At the potentials at which 1-heptanol oxidation starts, the mass in both base electrolyte and in 1-heptanol is at a minimum, or nearly so, which shows that water is driven away from the surface of gold prior to the oxidation of both gold and 1-heptanol. [ABSTRACT FROM AUTHOR]

Abstract: The UV/Vis spectral behavior of three solvatochromic N-alkyl α-pyridones of varying lipophilicity was investigated in aqueous solutions of a block copolymer at variable temperatures. The solvatochromic responses of the three analogues to the distinct microenvironments were compared and interpreted in terms of their different location in the microheterogeneous system. The interpretation was supported by 1H NMR measurements and by molecular dynamics simulations that mimicked the interactions of the dyes with the polymeric micelle in water. [Copyright &y& Elsevier]

In the search of new cymantrenyl- and ferrocenyl-sulfonamides as potencial inhibitors of human carbonic anhydrases (hCAs), four compounds based on N -ethyl or N -methyl benzenesulfonamide units have been obtained. These cymantrenyl (1a-b) and ferrocenyl (2a - b) derivatives were prepared by the reaction between aminobenzene sulfonamides ([NH 2 -(CH 2) n -(C 6 H 4)-SO 2 -NH 2)], where n = 1, 2) with cymantrenyl sulfonyl chloride (P1) or ferrocenyl sulfonyl chloride (P2), respectively. All compounds were characterized by conventional spectroscopic techniques and cyclic voltammetry. In the solid state, the molecular structures of compounds 1a , 1b , and 2b were determined by single-crystal X–ray diffraction. Biological evaluation as carbonic anhydrases inhibitors were carried out and showed derivatives 1b y 2b present a higher inhibition than the drug control for the Human Carbonic Anhydrase (hCA) II and IX isoforms (K I = 7.3 nM and 5.8 nM, respectively) and behave as selective inhibition for hCA II isoform. Finally, the docking studies confirmed they share the same binding site and interactions as the known inhibitors acetazolamide (AAZ) and agree with biological studies. New cymantrenyl- and ferrocenyl-sulfonamides based on N -ethyl or N -methyl benzenesulfonamide units have been obtained. All compounds were characterized by conventional spectroscopic techniques, cyclic voltammetry, and single-crystal X–ray diffraction. All compounds were evaluated as carbonic anhydrase inhibitors agents, and the docking studies were agreed with biological studies. [Display omitted] • New organometallic-sulfonamides with benzenesulfonamides units have been obtained. • All complexes were full characterized, included single-crystal X–ray diffraction. • Redox behavior of the complexes was studied by cyclic voltammetry. • Biological assays as carbonic anhydrase inhibitors agents were carried out. • The docking studies were carried out and these agreed with biological studies. [ABSTRACT FROM AUTHOR]

• The influence of the structure of butanol on its oxidation on a gold electrode in an alkaline medium was studied. • The boiling temperature is a good descriptor for the oxidation of butanols on gold electrode in alkaline medium. • Butanols with unsaturation in the carbon chain are more active than those without carbon-carbon double bond. • The gold electrode surface is more active if the active site has been newly regenerated. Alcohols are of great interest both for fuel cells and for the preparation of aldehydes. The electrooxidation of six C-4 alcohols (1-, 2- and iso-butanol, crotyl, cis-2-buten-1,4-diol and erythritol on gold in alkaline medium has been studied by cyclic voltammetry (CV), the Electrochemical Quartz Crystal Microbalance (EQCM) and Electrochemical Impedance Spectroscopy (EIS). Furthermore, molecular dynamics calculations were used for determining the probability of solvation of the alcoholic head, g(r), as a function of the distance, r, to the alcoholic head. This probability was found to be maximum at r = 2 Å The six alcohols fell into two groups. One group, namely 1-, 2- and iso-butanol, showed first-order electrooxidation kinetics at concentrations <20 mM, without poisoning of the electrode surface. These alcohols, as well as including crotyl, showed relative low reactivity (It was estimated as the ratio of the charge of peak b1 in a given alcohol to that of iso-butanol, the less active alcohol) correlation against the Radial Distribution Function (RDF) at a given distance (g(2 Å)), in total agreement with our hypothesis about the effect of the hydrophobicity of the analyte on the reactivity of the electrode. The second group, formed by crotyl, cis-2-buten-1,4-diol and erythritol, were almost 10 times more reactive, had a kinetic order near 0.5, showed adsorption on the gold surface, and their activity correlated better with their boiling points, that is, with their dipolar character. So, in the electrooxidation of unsaturated alcohols there is adsorption of residues and/or reaction products, which does not affect their high reactivity. [Display omitted] [ABSTRACT FROM AUTHOR]

Inclusion complexes based on β-cyclodextrin (β-CD) and antimicrobial compounds, were prepared by co-precipitation method, and characterized by entrapment efficiency (EE), thermal analysis, X-ray diffraction, 1H NMR spectroscopy, and water sorption. In addition, experiments associated to evaluate the effect of relative humidity on the release of active compounds and antifungal tests were performed. The analysis evidenced the encapsulation of active compounds into the β-CD structure with EE of 91 ± 4.1% and 66 ± 2.1% for β-CD/cinnamaldehyde and β-CD/eugenol complexes, respectively. Additionally, high relative humidities favored the release of active compounds from inclusion complexes. On the other hand, inclusion complexes were able to control the growth of B. cinerea , which was evidenced by a reduction of its mycelialradial growth. Finally, specific interactions between the active compounds and β-CD were evaluated through molecular dynamics simulation techniques. According to the obtained results, these complexes could be applied as additives in the design of antifungal packaging. Unlabelled Image • β-CD inclusion complexes were prepared by co-precipitation method. • Differences in host-guest interactions were evidenced. • Inclusion complexes evidenced antifungal activity against B. cinerea. • Higher relative humidities favored the release of active compounds. [ABSTRACT FROM AUTHOR]

Two series of diaza derivatives were prepared by solvent-free condensation of benzoic acid and 4-substituted phenylhydrazines in order to obtain phenylhydrazides (HYD series) and, by oxidation of these compounds, the corresponding benzoyldiazenes (DIA series). Both sets were evaluated as inhibitors of soybean 15-lipoxygenase activity and antioxidant capability in the FRAP and CUPRAC assays. The most potent inhibitors of both series exhibited IC 50 values in the low micromolar range. Kinetic studies showed that at least the more active compounds were competitive inhibitors. Docking results indicated that the most potent inhibitor interacts strongly with Ile-839 and iron in the active site. [ABSTRACT FROM AUTHOR]

In the search for new 5-LOX inhibitors, two ferrocenyl Schiff base complexes functionalized with catechol ((ƞ5-(E)-C 5 H 4 -N CH-3,4-benzodiol)Fe(ƞ5-C 5 H 5) (3a)) and vanillin ((ƞ5-(E)-C 5 H 4 -N CH-3-methoxy-4-phenol)Fe(ƞ5-C 5 H 5) (3b)) were obtained. Complexes 3a and 3b were biologically evaluated as 5-LOX inhibitors showed potent inhibition compared to their organic analogs (2a and 2b) and known commercial inhibitors, with IC 50 = 0.17 ± 0.05 μM for (3a) and 0.73 ± 0.06 μM for (3b) demonstrated a highly inhibitory and potent effect against 5-LOX due to the incorporation of the ferrocenyl fragment. Molecular dynamic studies showed a preferential orientation of the ferrocenyl fragment toward the non-heme iron of 5-LOX, which, together with electrochemical and in-vitro studies, allowed us to propose a competitive redox deactivation mechanism mediated by water, where Fe(III)-enzyme can be reduced by the ferrocenyl fragment. An E pa /IC 50 relationship was observed, and the stability of the Schiff bases was evaluated by SWV in the biological medium, observing that the hydrolysis does not affect the high potency of the complexes, making them interesting alternatives for pharmacological applications. Ferrocenyl Schiff base complexes are potent inhibitors of 5-Lypoxigenase through a competitive redox mechanism mediated by water (Fe(III)-enzyme/H 2 O/Fe(II)-ferrocene), making them interesting alternatives for pharmacological applications. [Display omitted] • Ferrocenyl Schiff base complexes showed potent inhibition on 5-Lipoxygenase. • Hydrolysis products were quantified by Square Wave Voltammetry. • Molecular dynamics of the ferrocenyl complexes were carried out. • Antioxidant assays were performed. • A redox inhibition was evidenced by electrochemical, in-silico , and in-vitro studies. [ABSTRACT FROM AUTHOR]

Abstract: A pair of solvatochromic phenolate betaines that differed only in their lipophilicity was synthesized. Their solvatochromic responses in pure solvents, in a DMSO–MeOH solvent mixture as well as in micellar solutions were different, an observation which confirmed the fact that sensor lipophilicity contributes to the interpretation of solvatochromism. Quantum mechanical calculations reproduced the observed spectral differences. Molecular dynamics simulations shed light on the solute–solvent interactions responsible for their differences in solvent mixtures. [Copyright &y& Elsevier]