Polyamide Layer Chromatography. VIII. Preparation of Polyamide Layer on Poly(ethylene terephthalate) Film and its Application to Aromatic Nitro Compounds

Poly(ethylene terephthalate) film was used as supporter for preparation of polyamide layer. The most convenient method of preparation was described. This layer can be cut into any size and its sensitivity is higher than the glass plate supported layer. Twenty aromatic nitro compounds were used to show the behavior of polyester film based polyamide layer.     

Selective modification of the 2-position of pyridoxol

Pyridoxol, protected by acetylation of the hydroxyl groups, has been converted to its N-oxide which upon reaction with perfluoroacetie anhydride yields a 2-nor-2-hydroxymethylpyridoxol derivative as an intermediate. This compound undergoes acyl migration from the 3-position. Protection of the pyridoxol hydroxyls by benzylalion followed by the same treatment yields the unrearranged α²-hydroxy derivative. This compound has been converted to a series of α²-substituted pyridoxols (X = -Cl, -Br, -OCOCH₃, -OCH₃, -OC₂H₅).     

Preparations and spectroscopic studies of organotin complexes of diclofenac

The reactions of the potent and widely used anti-inflammatory drug diclofenac, HL, with diorganotin(IV) oxides were studied. The dimeric tetraorganodistannoxane complexes [Me(2)LSnOSnLMe(2)](2), [Bu(2)LSnOSnLBu(2)](2), [Ph(2)LSnOSnLPh(2)](2) and the dibutyltin complex [Bu(2)SnL(2)], have been prepared and structurally characterized in the solid state by means of vibrational and 119Sn M?ssbauer spectroscopy. Determination of lattice dynamics by temperature-dependent 119Sn M?ssbauer spectroscopy. From the variable-temperature M?ssbauer effect, the Debye temperature was determined. The complexes have been characterized in solution by NMR (1H and 13C) spectroscopy. Vibrational, M?ssbauer, and NMR data are discussed in terms of the proposed structures.     

Terroir Effect on the Phenolic Composition and Chromatic Characteristics of Mencía/Jaen Monovarietal Wines: Bierzo D.O. (Spain) and Dão D.O. (Portugal)

‘Mencía’/‘Jaen’ it’s an important red grape variety, exclusive of the Iberian Peninsula, used in wine production namely in Bierzo D.O. and Dão D.O., respectively. This work evaluates the effect of the two different “terroirs” on the phenolic composition and chromatic characteristics of ‘Mencía’/‘Jaen’ monovarietal wines produced at an industrial scale in the same vintage. Using Principal Component Analysis (PCA), Partial Least Squares-Discrimination Analysis (PLS-DA), and Orthogonal PLS-DA (OPLS-DA) it was found that peonidin-3-coumaroylglucoside, petunidin-3-glucoside, malvidin-3-coumaroylglucoside, peonidin-3-glucoside, malvidin-3-acetylglucoside, malvidin-3-glucoside, and ferulic acid were the phenolic compounds with the highest differences between the two regions. PLS regression allowed to correlate the differences in lightness (L*) and redness (a*) of wines from ‘Jaen’ and ‘Mencía’ to differences in colored anthocyanins, polymeric pigments, total pigments, total anthocyanins, cyanidin-3-acetylglucoside, delphinidin-3-acetylglucoside, delphinidin-3-glucoside, peonidin-3-coumaroylglucoside, petunidin-3-glucoside and malvidin-3-glucoside in wines, and the colorless ferulic, caffeic, and coutaric acids, and ethyl caffeate. The wines a* values were more affected by colored anthocyanins, ferulic acid, total anthocyanins, delphinidin-3-acetylglucoside, delphinidin-3-glucoside and petunidin-3-acetylglucoside, and catechin. The positive influence of ferulic acid in the a* values and ferulic, caffeic, coutaric acids, and ethyl caffeate on the L* values can be due to the co-pigmentation phenomena. The higher dryness and lower temperatures during the September nights in this vintage might explain the differences observed in the anthocyanin content and chromatic characteristics of the wines.     

The Density Functional Theory Account of Interplaying Long-Range Exchange and Dispersion Effects in Supramolecular Assemblies of Aromatic Hydrocarbons with Spin

Aromatic hydrocarbons with fused benzene rings and regular triangular shapes, called n-triangulenes according to the number of rings on one edge, form groundstates with n-1 unpaired spins because of topological reasons. Here, we focus on methodological aspects emerging from the density functional theory (DFT) treatments of dimer models of the n = 2 triangulene (called also phenalenyl), observing that it poses interesting new problems to the issue of long-range corrections. Namely, the interaction comprises simultaneous spincoupling and van der Waals effects, i.e., a technical conjuncture not considered explicitly in the benchmarks calibrating long-range corrections for the DFT account of supramolecular systems. The academic side of considering dimer models for calculations and related analysis is well mirrored in experimental aspects, and synthetic literature revealed many compounds consisting of stacked phenalenyl cores, with intriguing properties, assignable to their long-range spin coupling. Thus, one may speculate that a thorough study assessing the performance of state-of-the-art DFT procedures has relevance for potential applications in spintronics based on organic compounds.     

Monthly Increase in Vitamin D Levels upon Supplementation with 2000 IU/Day in Healthy Volunteers: Result from “Integriamoci”, a Pilot Pharmacokinetic Study

Vitamin D (VD) is a calcium- and phosphate-controlling hormone used to treat bone disorders; yet, several other effects are progressively emerging. VD deficiency is highly prevalent worldwide, with suboptimal exposure to sunlight listed among the leading causes: oral supplementation with either cholecalciferol or calcitriol is used. However, there is a scarcity of clinical studies investigating how quickly VD concentrations can increase after supplementation. In this pilot study, the commercial supplement ImmuD3 (by Erboristeria Magentina^®) was chosen as the source of VD and 2000 IU/day was administered for one month to 21 healthy volunteers that had not taken any other VD supplements in the previous 30 days. Plasma VD levels were measured through liquid chromatography coupled to tandem mass spectrometry after 7, 14, and 28 days of supplementation. We found that 95% of the participants had insufficient VD levels at baseline (<30 ng/mL; median 23.72 ng/mL; IQR 18.10–26.15), but after 28 days of supplementation, this percentage dropped to 62% (median 28.35 ng/mL; IQR 25.78–35.20). The median increase in VD level was 3.09 ng/mL (IQR 1.60–5.68) after 7 days and 8.85 ng/mL (IQR 2.85–13.97F) after 28 days. This study suggests the need for continuing VD supplementation and for measuring target level attainment.     

Impact of High-Pressure Homogenization on the Cell Integrity of Tetradesmus obliquus and Seed Germination

Microalgae have almost unlimited applications due to their versatility and robustness to grow in different environmental conditions, their biodiversity and variety of valuable bioactive compounds. Wastewater can be used as a low-cost and readily available medium for microalgae, while the latter removes the pollutants to produce clean water. Nevertheless, since the most valuable metabolites are mainly located inside the microalga cell, their release implies rupturing the cell wall. In this study, Tetradesmus obliquus grown in 5% piggery effluent was disrupted using high-pressure homogenization (HPH). Effects of HPH pressure (100, 300, and 600 bar) and cycles (1, 2 and 3) were tested on the membrane integrity and evaluated using flow cytometry and microscopy. In addition, wheat seed germination trials were carried out using the biomass at different conditions. Increased HPH pressure or number of cycles led to more cell disruption (75% at 600 bar and 3 cycles). However, the highest increase in wheat germination and growth (40–45%) was observed at the lowest pressure (100 bar), where only 46% of the microalga cells were permeabilised, but not disrupted. Non-treated T. obliquus cultures also revealed an enhancing effect on root and shoot length (up to 40%). The filtrate of the initial culture also promoted shoot development compared to water (21%), reinforcing the full use of all the process fractions. Thus, piggery wastewater can be used to produce microalgae biomass, and mild HPH conditions can promote cell permeabilization to release sufficient amounts of bioactive compounds with the ability to enhance plant germination and growth, converting an economic and environmental concern into environmentally sustainable applications.     

Mixing of electronic states in pentacene adsorption on copper

By combining experimental and theoretical approaches, we study the adsorption of pentacene on copper as a model for the coupling between aromatic molecules and metal surfaces. Our results for the interface electronic structure are not compatible with a purely physisorption picture, which is conventionally employed for such systems. Nay, we demonstrate electronic mixing between molecular orbitals and metal electronic states.     

Reorientational relaxation and rotational–translational coupling in water clusters in a d.c. external electric field

Molecular dynamics simulations have been carried out for small water clusters (N=16, 32, 64) in a d.c. electric field at T=200 K. It was shown that for relatively weak fields, there was a significant decrease of reorientational and structural relaxation times for all cluster sizes examined. Regarding the molecular reorientational motions, in the strong field regime, a decoupling of tumbling and spinning librations was observed. Reorientational relaxation times of the dipole and vector joining the two hydrogen atoms were found to follow different relaxation laws, with the former decreasing and the latter increasing with electric field increase. These trends were qualitatively explained by invoking the Debye model with field-dependent friction for dipole librations and the symmetric double-well for spinning rotations on a plane perpendicular to the field axis. Finally, the interdependence of the reorientation on the translational modes of the cluster was indicated, with the translationally slow molecules being rotationally slow as well and vice versa.