Cs2CO3-Promoted Alkylation of 3-Cyano-2(1H)-pyridones: Anticancer Evaluation and Molecular Docking.

Herein, a Cs2CO3-promoted N-alkylation of 3-cyano-2(1H)-pyridones containing alkyl groups with diverse alkyl halides to synthesize N-alkyl-2-pyridones over O-alkylpyridines is reported. Alkyl dihalides resulted in complex mixtures of N- and O-alkylated products. The primary factor influencing regioselectivity in these reactions is the electronic effects of substituents on the 2(1H)-pyridone ring, as evidenced by the preferential formation of O-alkylpyridines upon the introduction of aryl groups. Remarkably, we efficiently employed CuAAC and Ti(Oi-Pr)4-catalyzed amidation reactions to functionalize N-alkyl-2-pyridones containing propargyl and ester groups, leading to the synthesis of 1,2,3-triazoles and amides, respectively. Moreover, O-alkylpyridines 10b and 10d displayed remarkable selectivity toward the A-498 renal cancer cell line with growth inhibition percentages (%GI) of 54.75 and 67.64, respectively. The binding modes of compounds 10b and 10d to the PIM-1 kinase enzyme were determined through molecular docking studies.

Biochar-MgO from Soursop Seeds in the Production of Biofuel Additive Intermediates.

The conversion of residual biomass from fruit seeds into biochar can be achieved using MgCl2 as an activating agent and calcining at 700 °C. The resulting MgO-biochars were employed in the aldol condensation reaction between furfural and acetone. This reaction is essential as the first step in the obtention of biofuels derived from biomass. The biochars were characterized through various physicochemical techniques, revealing that the presence of MgO nanoparticles deposited on the carbon surface modifies the structural and acidic-basic properties of the carbonaceous materials with a graphitic structure. The biochar with a surface content of MgO of 0.34 % w/w enables the achievement of 100 % of selectivity towards 4-(2-furanyl)-3-buten-2-one (I) with quantitative conversions under optimized conditions. This property highlights the potential of using this type of biochar, commonly used for CO2 capture, as a versatile acidic-basic catalyst, thereby introducing a novel approach to sustainable chemistry.

Efficient NiO/F-TiO2 nanocomposites for 4-chlorophenol photodegradation.

This work aimed to study NiO/F-TiO2 composites in the photocatalytic degradation of 4-chlorophenol. F-TiO2 support was prepared by in-situ fluorination of TiO2 using the sol-gel method. The heterostructured materials were prepared by wet impregnation method, varying NiO content (0.5, 1.0, and 2.0% wt). The solids were characterized by X-ray fluorescence, X-ray diffraction, nitrogen physisorption, diffuse reflectance UV-Vis spectrophotometry, infrared spectroscopy, and X-ray photoelectron spectroscopy. The characterization studies showed that the coupling of TiO2 with fluoride ions promoted the generation of ≡Ti-F surface species that could be responsible for the decrease in the recombination frequency of charge carriers and the increased photoactivity. In addition, it was found that the coupling of NiO/F-TiO2 semiconductors improved the photocatalytic properties of the fluorinated support, obtaining higher percentages of degradation and mineralization of the phenolic contaminant. These results are possibly a consequence of factors such as the formation of larger crystallites, lower band gap energies, and the generation of p-n type interfacial heterojunctions that potentiate the proper separation of electron-hole pairs. An effect of NiO content on photoactivity was observed, being a percentage of 1.0% wt the optimum in this photocatalytic treatment.

Bioactive 2-pyridone-containing heterocycle syntheses using multicomponent reactions.

2-Pyridone-containing heterocycles are considered privileged scaffolds in drug discovery due to their behavior as hydrogen bond donors and/or acceptors and nonpeptidic mimics, and remarkable physicochemical properties such as metabolic stability, solubility in water, and lipophilicity. This review provides a comprehensive overview of multicomponent reactions (MCRs) for the synthesis of 2-pyridone-containing heterocycles. In particular, it covers the articles published from 1999 to date related to anticancer, antibacterial, antifungal, anti-inflammatory, α-glucosidase inhibitor, and cardiotonic activities of 2-pyridone-containing heterocycles obtained exclusively by an MCR. The discussion focuses on bioactivity data, synthetic approaches, plausible reaction mechanisms, and molecular docking simulations to facilitate comparison and underscore the applications of the 2-pyridone motif in drug discovery and medicinal chemistry. We also present our conclusions and outlook for the future.

Development of an insect cell-based adeno-associated virus packaging cell line employing advanced Rep gene expression control system.

The insect cell-based baculovirus expression vector (BEV) system is a leading platform for scalable production of adeno-associated viruses (AAVs). The previously described One-Bac system consists of an insect packaging cell line harboring the AAV Rep and Cap genes and a BEV carrying the transgene and AAV inverted terminal repeats. Here we describe a new system where we successfully translated the molecular design of a double AAV Rep expression cassette to inducible plasmid vectors. These optimized plasmid vectors employ non-canonical late promoters and alternative start codons that alleviate promoter-promoter competition. Because too much Rep expression can be toxic to the host cells, tighter regulation of AAV Rep expression is warranted. This has been achieved by adopting alternate baculovirus homologous region enhancers. Inoculation of the resultant stable insect Rep packaging cell line by a recombinant BEV produced high-titer recombinant AAV (rAAV) preparations (1 × 1011 genome copies/mL). Sequential batch reactor experiments indicate that this system is amenable to large-scale AAV production. We generated an insect packaging cell line that employs an optimized Rep gene control system, ensuring stable and appropriate Rep expression. This platform produces potent and high-yield AAV particles and demonstrates potential for scale up.

Tailoring Chlorthalidone Aqueous Solubility by Cocrystallization: Stability and Dissolution Behavior of a Novel Chlorthalidone-Caffeine Cocrystal.

A cocrystal of the antihypertensive drug chlorthalidone (CTD) with caffeine (CAF) was obtained (CTD-CAF) by the slurry method, for which a 2:1 stoichiometric ratio was found by powder and single-crystal X-ray diffraction analysis. Cocrystal CTD-CAF showed a supramolecular organization in which CAF molecules are embedded in channels of a 3D network of CTD molecules. The advantage of the cocrystal in comparison to CTD is reflected in a threefold solubility increase and in the dose/solubility ratios, which diminished from near-unit values for D0D to 0.29 for D0CC. Furthermore, dissolution experiments under non-sink conditions showed improved performance of CTD-CAF compared with pure CTD. Subsequent studies showed that CTD-CAF cocrystals transform to CTD form I where CTD precipitation inhibition could be achieved in the presence of pre-dissolved polymer HPMC 80-120 cPs, maintaining supersaturation drug concentrations for at least 180 min. Finally, dissolution experiments under sink conditions unveiled that the CTD-CAF cocrystal induced, in pH-independent manner, faster and more complete CTD dissolution when compared to commercial tablets of CTD. Due to the stability and dissolution behavior of the novel CTD-CAF cocrystal, it could be used to develop solid dosage forms using a lower CTD dose to obtain the same therapeutic response and fewer adverse effects.

Nanoconfinement of a Pharmaceutical Cocrystal with Praziquantel in Mesoporous Silica: The Influence of the Solid Form on Dissolution Enhancement.

Nanoconfinement is a recent strategy to enhance solubility and dissolution of active pharmaceutical ingredients (APIs) with poor biopharmaceutical properties. In this work, we combine the advantage of cocrystals of racemic praziquantel (PZQ) containing a water-soluble coformer (i.e., increased solubility and supersaturation) and its confinement in a mesoporous silica material (i.e., increased dissolution rate). Among various potential cocrystalline phases of PZQ with dicarboxylic acid coformers, the cocrystal with glutaric acid (PZQ-GLU) was selected and successfully loaded by the melting method into nanopores of SBA-15 (experimental pore size of 5.6 nm) as suggested by physical and spectroscopic characterization using various complementary techniques like N2 adsorption, powder X-ray diffraction (PXRD), infrared spectroscopy (IR), solid-state NMR (ss-NMR), differential scanning calorimetry (DSC), and field emission-scanning electron microscopy (FE-SEM) analysis. The PZQ-GLU phase confined in SBA-15 presents more mobility according to ss-NMR studies but still retains its cocrystal-like features in the IR spectra, and it also shows depression of the melting transition temperature in DSC. On the contrary, pristine PZQ loaded into SBA-15 was found only in the amorphous state, according to the aforementioned studies. This dissimilar behavior of the composites was attributed to the larger crystal lattice of PZQ over the PZQ-GLU cocrystal (3320.1 vs 1167.9 Å3) and to stronger intermolecular interactions between PZQ and GLU, facilitating the confinement of a more mobile solid-like phase in the constrained channels. Powder dissolution studies under extremely nonsink conditions (SI = 0.014) of the confined PZQ-GLU and amorphous PZQ phases embedded in mesoporous silica showed transient supersaturation behavior when dissolving in simulated gastric fluid (HCl pH 1.2 at 37 ± 0.5 °C) in a similar fashion to the bare cocrystal PZQ-GLU. A comparison of the area under the curve (AUC0-90 min) of the dissolution profiles afforded a dissolution advantage of 2-fold (p < 0.05) of the new solid phases over pristine racemic PZQ after 90 min; under these conditions, the solubilized API reprecipitated as the recently discovered PZQ hemihydrate (PZQ-HH). In the presence of a cellulosic polymer, sustained solubilization of PZQ from composites SBA-15/PZQ or SBA-15/PZQ-GLU was observed, increasing AUC0-90 min up to 5.1-fold in comparison to pristine PZQ. The combination of a confined solid phase in mesoporous silica and a methylcellulose polymer in the dissolution medium effectively maintained the drug solubilized during times significant to promote absorption. Finally, powder dissolution studies under intermediate nonsink conditions (SI = 1.99) showed a fast release profile from the nanoconfined PZQ-GLU phase in SBA-15, which reached rapid saturation (95% drug dissolved at 30 min); the amorphous PZQ composite and bare PZQ-GLU also displayed an immediate release of the API but at a lower rate (69% drug dissolved at 30 min). In all of these cases, a large dissolution advantage was observed from any of the novel solid phases over PZQ.

Caffeine photocatalytic degradation using composites of NiO/TiO2-F and CuO/TiO2-F under UV irradiation.

The interest in the removal of emerging contaminants has increased in the last decade. Photocatalytic degradation using p-n heterojunctions could effectively provide the degradation of these type of substances that are persistent in the environment. In this work, the synthesis, characterization, and photocatalytic evaluation of TiO2-F as well as CuO/TiO2-F and NiO/TiO2-F composite materials were studied in the photo-assisted degradation of caffeine using UV radiation. The fluorination of titanium dioxide induced changes in some physicochemical properties of the materials, which contributed to a decrease in surface area and bandgap energy as well as an increase in crystallite size as compared to pristine TiO2. ≡Ti-F species were evidenced to be formed, which could favor charge separation processes. A highest segregation of CuO species in comparison with NiO on the surface of TiO2-F could be formed, which could increase defect sites and decrease the band gap. The formation of a heterojunction between the semiconductors was evidenced, responsible for the observed improvements in photocatalytic properties of the composite materials. The photocatalytic tests evidenced an important degradation of caffeine; however, mineralization was incomplete. The stability of the composite materials and their potential use in the photocatalytic treatment of caffeine was evaluated by reuse tests.

Whey as an Alternative Nutrient Medium for Growth of Sporosarcina pasteurii and Its Effect on CaCO3 Polymorphism and Fly Ash Bioconsolidation.

Whey in large quantities can cause environmental problems when discarded, because it reduces dissolved oxygen and aquatic life. Nonetheless, it could be used as an easily available and economical alternative to reduce culture medium costs in microbially induced calcium carbonate precipitation (MICP). In this work, a native Sporosarcina pasteurii was isolated and then cultured by using different proportions of whey (W) in nutrient broth (NB). The solids were characterized by XRD, FT-IR, TGA, and SEM. The potential applications in bioconsolidation were also studied. Whey concentration was directly related to CaCO3 production. Higher whey concentrations reduced calcium carbonate purity to nearly 80%. All experiments showed calcite and vaterite fractions, where a whey increment in the media increased calcite content and decreased vaterite content, causing a decrease in crystal size. MICP improved compressive strength (CS) in sand and fly ash. The best CS results were obtained by fly ash treated with 25 W-75 NB (37.2 kPa) and sand with 75 W-25 NB (32.1 kPa). Whey changed crystal polymorphism in biogenic CaCO3 production. Material bioconsolidation depends on the CaCO3 polymorph, thus fly ash was effectively bioconsolidated by crystallization of vaterite and sand by crystallization of calcite.

Impacto de la participación del residente y su rol en desenlaces clínicos de los pacientes llevados a colecistectomía en un hospital universitario / Impact of resident participation and their role on clinical outcomes of patients undergoing cholecystectomy at a university hospita

Introducción. La colecistectomía es uno de los procedimientos quirúrgicos más realizados a nivel mundial, por lo que su aprendizaje es cada vez más necesario para los médicos residentes en entrenamiento, pero sin comprometer la seguridad de los pacientes. El objetivo de este estudio fue determinar el impacto de la participación de los médicos residentes en los principales desenlaces clínicos de la colecistectomía. Métodos. Se realizó un estudio prospectivo de cohortes, donde se incluyeron los pacientes llevados a colecistectomía laparoscópica, desde junio de 2019 hasta julio de 2020. Se llevó a cabo el análisis estadístico para describir medidas de frecuencia, tendencia central, dispersión y análisis bivariados para los desenlaces de interés. Resultados. Se incluyeron 482 pacientes a quienes se les practicó colecistectomía, 475 de ellas por vía laparoscópica. El 62,5 % fueron mujeres y el 76,2 % se realizaron de carácter urgente. En el 96 % de los procedimientos se contó con la participación de un residente. En el análisis bivariado no se encontró una diferencia estadísticamente significativa entre la participación del residente y un impacto negativo en los desenlaces clínicos de las variables relevantes. Discusión. No hay evidencia de que la participación de médicos residentes en la colecistectomía laparoscópica se asocie con desenlaces adversos en los pacientes, lo que sugiere estar en relación con una introducción temprana y responsable a este procedimiento por parte de los docentes, permitiendo que la colecistectomía sea un procedimiento seguro

Introduction. Cholecystectomy is one of the most performed surgical procedures worldwide, so its learning is increasingly necessary for resident physicians in training, but without compromising the safety of patients. The objective of this study was to determine the impact of the participation of resident physicians on the main clinical outcomes of cholecystectomy. Methods. A prospective cohort study was performed, which included patients undergoing laparoscopic cholecys-tectomy from June 2019 to July 2020. Statistical analysis was carried out to describe measures of frequency, central tendency, dispersion, and bivariate analysis for outcomes of interest. Results. 482 patients who underwent cholecystectomy were included, 475 of them laparoscopically; 62.5% were women and 76.2% were performed urgently, and 96% of the procedures involved the participation of a resident. In the bivariate analysis, no statistically significant difference was found between resident participation and a negative impact on the clinical outcomes of the relevant variables. Discussion. There is no evidence that the participation of resident physicians in laparoscopic cholecystectomy is associated with adverse outcomes in patients, which suggests being related to an early and responsible introduction to this procedure by teachers, allowing cholecystectomy to be a safe procedure

A Radiometric Technique for Monitoring the Desulfurization Process of Blister Copper.

In this paper, a novel optical technique for following the progress of the blister copper desulfurization process is presented. The technique is based on the changes observed in the continuous spectrum of the visible-near-infrared (VIS-NIR) radiation that the blister melt emits while the chemical reactions of the sulfur elimination process are taking place. Specifically, the proposed technique uses an optical probe composed of an optical fiber, a collimating lens, and a quartz tube, which is immersed in the melt. This optical probe provides a field of view of the blowing zone where the desulfurization reaction occurs. The experimental results show that the melt VIS-NIR total irradiance evolves inversely to the SO2 concentration reported by a gas analyzer based on differential optical absorption spectroscopy. Furthermore, the blister copper spectral emissivity as well as the total emissivity observed throughout the process show strong correlation with the sulfur content during desulfurization reaction.

Biogeographical factors determining Triatoma recurva distribution in Chihuahua, México, 2014. / Factores biogeográficos determinantes de la distribución de Triatoma recurva en Chihuahua, México, 2014

INTRODUCTION: Triatoma recurva is a Trypanosoma cruzi vector whose distribution and biological development are determined by factors that may influence the transmission of trypanosomiasis to humans. OBJECTIVE: To identify the potential spatial distribution of Triatoma recurve, as well as social factors determining its presence. MATERIALS AND METHODS: We used the MaxEnt software to construct ecological niche models while bioclimatic variables (WorldClim) were derived from the monthly values of temperature and precipitation to generate biologically significant variables. The resulting cartography was interpreted as suitable areas for T. recurva presence. RESULTS: Our results showed that the precipitation during the driest month (Bio 14), the maximum temperature during the warmest month (Bio 5), and the altitude (Alt) and mean temperature during the driest quarter (Bio 9) determined T. recurva distribution area at a higher percentage evidencing its strong relationship with domestic and surrounding structures. CONCLUSIONS: This methodology can be used in other geographical contexts to locate potential sampling sites where these triatomines occur.

Introducción. Triatoma recurva es un vector de Trypanosoma cruzi cuya existencia y desarrollo biológico están determinados por factores que pueden influir en la transmisión de la tripanosomiasis a los seres humanos. Objetivo. Determinar una posible distribución espacial de Triatoma recurva y algunos factores sociales que determinan su presencia. Materiales y métodos. El modelado de nicho ecológico se hizo con el programa MaxEnt empleando las variables bioclimáticas (WorldClim) derivadas de los valores mensuales de temperatura y precipitación para generar variables biológicamente significativas. La cartografía resultante evidenció áreas adecuadas para la presencia de T. recurva. Resultados. Los resultados indicaron que la precipitación del mes más seco (Bio 14), la temperatura máxima del mes más cálido (Bio 5), y la altitud (Alt) y la temperatura media del trimestre más seco (Bio 9), determinaron en mayor porcentaje el área de distribución de T. recurva, observándose que es una especie con una acentuada relación con las estructuras domésticas y circundantes. Conclusión. Esta metodología puede emplearse en otros contextos geográficos para localizar posibles sitios de muestreo de estos triatominos.

Biogeographical factors determining Triatoma recurva distribution in Chihuahua, México, 2014 / Factores biogeográficos determinantes de la distribución de Triatoma recurva en Chihuahua, México, 2014

Introduction: Triatoma recurva is a Trypanosoma cruzi vector whose distribution and biological development are determined by factors that may influence the transmission of trypanosomiasis to humans. Objective: To identify the potential spatial distribution of Triatoma recurve, as well as social factors determining its presence. Materials and methods: We used the MaxEnt software to construct ecological niche models while bioclimatic variables (WorldClim) were derived from the monthly values of temperature and precipitation to generate biologically significant variables. The resulting cartography was interpreted as suitable areas for T. recurva presence. Results: Our results showed that the precipitation during the driest month (Bio 14), the maximum temperature during the warmest month (Bio 5), and the altitude (Alt) and mean temperature during the driest quarter (Bio 9) determined T. recurva distribution area at a higher percentage evidencing its strong relationship with domestic and surrounding structures. Conclusions. This methodology can be used in other geographical contexts to locate potential sampling sites where these triatomines occur.

Introducción. Triatoma recurva es un vector de Trypanosoma cruzi cuya existencia y desarrollo biológico están determinados por factores que pueden influir en la transmisión de la tripanosomiasis a los seres humanos. Objetivo. Determinar una posible distribución espacial de Triatoma recurva y algunos factores sociales que determinan su presencia. Materiales y métodos. El modelado de nicho ecológico se hizo con el programa MaxEnt empleando las variables bioclimáticas (WorldClim) derivadas de los valores mensuales de temperatura y precipitación para generar variables biológicamente significativas. La cartografía resultante evidenció áreas adecuadas para la presencia de T. recurva. Resultados. Los resultados indicaron que la precipitación del mes más seco (Bio 14), la temperatura máxima del mes más cálido (Bio 5), y la altitud (Alt) y la temperatura media del trimestre más seco (Bio 9), determinaron en mayor porcentaje el área de distribución de T. recurva, observándose que es una especie con una acentuada relación con las estructuras domésticas y circundantes. Conclusión. Esta metodología puede emplearse en otros contextos geográficos para localizar posibles sitios de muestreo de estos triatominos.

Boron-Nitrogen Double Tweezers Comprising Arylboronic Esters and Diamines: Self-Assembly in Solution and Adaptability as Hosts for Aromatic Guests in the Solid State.

The thermodynamic stability of 1 : 1 and 2 : 1 boron-nitrogen (B←N) adducts formed between aromatic boronic esters with mono- and diamines was studied in solution by NMR and UV-vis spectroscopy with association energies (ΔG°) ranging from -11 to -28 kJ mol-1 . The effect of different substituents in the boronic ester, the nature of the diamine linker, and the effect of the solvent was explored. Stable 2 : 1 B←N adducts with diamines such as 1,3-diaminopropane were produced in solutions of hydrogen-bonding acceptor solvents (acetonitrile and ethyl acetate), which can be isolated in the solid state as crystalline solvates, whereas the use of noncoordinating solvents such as 1,2-dichloroethane afforded mainly 1 : 1 B←N adducts. In suitable combinations, aromatic bis-pyridyl diamines produced stable 2 : 1 B←N adducts that were isolated either as solvent-free solids, solvates, or cocrystals. In these crystalline forms, double-tweezer hosts were observed with an exceptional syn/anti conformational guest-adaptability driven by simultaneous donor-acceptor and C-H⋅⋅⋅π interactions in the tweezer cavities, resembling preorganized covalent tweezer hosts. Interestingly, cocrystals with electron-rich guests such as tetrathiafulvalene and pyrene showed non-centrosymmetric crystal lattices with infinite π-stacked donor-acceptor columns.

Effect of Metal Content on Ethanol Decomposition over Ni-Co Catalysts Supported on La-Ce Oxides.

The search for catalysts with features that can improve coke resistance and decrease byproduct formation is a current goal in H2 production from renewable sources. In this work, the effect of the presence of Ni nanoparticles over Co/La-Ce oxides on the ethanol decomposition reaction was studied. Catalysts were synthetized using as precursor a La0.8Ce0.2NixCo1-xO3 perovskite-type material to ensure a low segregation of phases and a high dispersion of metals. After reduction at 873 K, the perovskite structure was destroyed, and metal Co-Ni particles were supported over a lanthanum-cerium oxide. The materials were characterized by different techniques before and after reaction. Solids exhibited metal particle sizes between 5 and 15 nm demonstrating the advantages of the preparation method to obtain Ni-Co alloys. Although the results of adsorption of ethanol followed by diffuse reflectance infrared fourier transformed spectroscopy (DRIFTS) showed acetate species strongly adsorbed on the catalyst's surface, the material (Ni0.7Co0.3/La0.8Ce0.2) with the lowest particle size was the most stable system leading to the lowest amount of carbon deposits during ethanol decomposition. This catalyst showed the better performance, with a higher ethanol conversion (98.4%) and hydrogen selectivity (75%). All catalysts exhibited carbonaceous deposits, which were an ordered and disordered carbon phase mixture.

Synthesis of Biologically Active Molecules through Multicomponent Reactions.

Focusing on the literature progress since 2002, the present review explores the highly significant role that multicomponent reactions (MCRs) have played as a very important tool for expedite synthesis of a vast number of organic molecules, but also, highlights the fact that many of such molecules are biologically active or at least have been submitted to any biological screen. The selected papers covered in this review must meet two mandatory requirements: (1) the reported products should be obtained via a multicomponent reaction; (2) the reported products should be biologically actives or at least tested for any biological property. Given the diversity of synthetic approaches utilized in MCRs, the highly diverse nature of the biological activities evaluated for the synthesized compounds, and considering their huge structural variability, much of the reported data are organized into concise schemes and tables to facilitate comparison, and to underscore the key points of this review.

HLA-G Ins/Del polymorphism and +3142C/G SNP are not related to neuromyelitis optica spectrum disorder (NMOSD) development, disability status or anti-aquaporin 4 presence in Brazilian patients.

We analyzed the association of polymorphisms from the 3' untranslated region of the HLA-G gene in 70 neuromyelitis optica spectrum disorder (NMOSD) patients and 162 healthy controls. No associations were found between the polymorphisms in NMOSD when compared to healthy controls, serology of the anti-AQP4 NMOSD biomarker and Expanded Disability Status Scale (EDSS). In conclusion, the 3' untranslated region 14 bp Ins/Del and +3142C/G polymorphisms seem not to be associated with NMOSD susceptibility, autoantibody production, nor a neurological deficit in patients.

Dissolution Advantage of Nitazoxanide Cocrystals in the Presence of Cellulosic Polymers.

The effect of hydroxypropyl methylcellulose (HPMC) and methylcellulose (Methocel® 60 HG) on the dissolution behavior of two cocrystals derived from nitazoxanide (NTZ), viz., nitazoxanide-glutaric acid (NTZ-GLU, 1:1) and nitazoxanide-succinic acid (NTZ-SUC, 2:1), was explored. Powder dissolution experiments under non-sink conditions showed similar dissolution profiles for the cocrystals and pure NTZ. However, pre-dissolved cellulosic polymer in the phosphate dissolution medium (pH 7.5) modified the dissolution profile of NTZ when starting from the cocrystals, achieving transient drug supersaturation. Subsequent dissolution studies under sink conditions of polymer-based pharmaceutical powder formulations with NTZ-SUC cocrystals gave a significant improvement of the apparent solubility of NTZ when compared with analogous formulations of pure NTZ and the physical mixture of NTZ and SUC. Scanning electron microscopy and powder X-ray diffraction analysis of samples recovered after the powder dissolution studies showed that the cocrystals undergo fast dissolution, drug supersaturation and precipitation both in the absence and presence of polymer, suggesting that the solubilization enhancement is due to polymer-induced delay of nucleation and crystal growth of the less soluble NTZ form. The study demonstrates that the incorporation of an appropriate excipient in adequate concentration can be a key factor for inducing and maintaining the solubilization of poorly soluble drugs starting from co-crystallized solid forms. In such a way, cocrystals can be suitable for the development of solid dosage forms with improved bioavailability and efficacy in the treatment of important parasitic and viral diseases, among others.

Channel Confinement of Aromatic Petrochemicals via Aryl-Perfluoroaryl Interactions With a B←N Host.

We report channel confinement properties of an electron-deficient boron host derived from the orthogonal B←N interaction between a boronic ester and trans-pentafluorostilbazole. The boron host forms one-dimensional channels in the crystalline solid state when crystallized with common electron-rich aromatic petrochemicals (i.e., benzene, toluene, o-xylene) to form solvates and a cocrystal with stilbene. Molecular confinement of the electron-rich molecules in the solids is achieved through a combination of aryl-perfluoroaryl interactions (π-πF) and hydrogen bonds.

Powder and Nanotubes Titania Modified by Dye Sensitization as Photocatalysts for the Organic Pollutants Elimination.

In this study, titanium dioxide powder obtained by the sol-gel method and TiO2 nanotubes, were prepared. In order to increase the TiO2 photoactivity, the powders and nanotubes obtained were modified by dye sensitization treatment during the oxide synthesis. The sensitizers applied were Quinizarin (Q) and Zinc protoporphyrin (P). The materials synthesized were extensively characterized and it was found that the dye sensitization treatment leads to modify the optical and surface properties of Titania. It was also found that the effectiveness of the dye-sensitized catalysts in the phenol and methyl orange (MO) photodegradation strongly depends on the dye sensitizer employed. Thus, the highest degradation rate for MO was obtained over the conventional Q-TiO2 photocatalyst. In the case of the nanotubes series, the most effective photocatalyst in the MO degradation was based on TiO2-nanotubes sensitized with the dye protoporfirin (ZnP). Selected catalysts were also tested in the phenol and MO photodegradation under visible light and it was observed that these samples are also active under this radiation.