Crystal structure, spectroscopy, DFT, and thermal studies of 3-cyano-2(1H)-pyridones as potential anticancer agents.

A series of 3-cyano-2(1H)-pyridones 4a-c were efficiently synthesized using an expeditious microwave-assisted multicomponent approach. Single-crystal XRD analysis revealed the presence of six independent molecules in the asymmetric unit cell for all compounds, with the crystal packing stabilized by a network of cyclic dimers formed by N-H⋯O[double bond, length as m-dash]C and C-H⋯O[double bond, length as m-dash]C intermolecular interactions. Additional supramolecular interactions, including C-H⋯π, C-N⋯π, and π⋯π, and C-H⋯X (for halogenated derivatives, i.e., 4b and 4c), appear crucial for crystal stabilization. Density Functional Theory (DFT) calculations were employed to understand the electronic structures and potential binding affinities. Comprehensive spectroscopic characterization by FT-IR, UV-Vis, NMR, and HMRS techniques confirmed the structures of all synthesized compounds. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to evaluate the thermal stability of these compounds. The in vitro anticancer activity was evaluated against a panel of 60 human cancer cell lines, demonstrating promising activity against non-small-cell lung and breast cancer cell lines. Notably, compounds 4a and 4c exhibited the highest anticancer activity against the HOP-92 and MCF7 cell lines, with growth inhibition percentages (GI%) of 54.35 and 40.25, respectively.

Direct photodegradation of internally mixed sodium chloride and malonic acid single aerosols: Impact of the photoproducts on the hygroscopic properties of the particles.

Sea-salt aerosols (SSA) are one of the key natural aerosols in our atmosphere, consisting predominantly of sodium chloride (NaCl). Throughout their atmospheric transport, these aerosols undergo complex internal mixing, giving rise to a rich variety of inorganic and organic species, including dicarboxylic acids. This study investigates firstly the composition and deliquescence properties of coarse particles containing pure malonic acid (MA2, CH2(COOH)2) and internally mixed NaCl and MA2, by means of an acoustic levitation system coupled with a Raman microspectrometer. Secondly, we report here the first experimental observation and characterization of the products arising from photochemical reactions under UV-Visible irradiation (338 ≤ λ ≤ 414 nm) in the absence of an oxidant under acoustic levitation conditions in MA2 and NaCl/MA2 aerosols. Furthermore, the impact of photodegradation on the hygroscopic properties of these particles is examined. We confirmed the irreversible formation of monosodium malonate (NaMA, HOOCCH2COONa), which coexists with NaCl or MA2 on non-irradiated particles. We also demonstrated the formation of oxalic acid (OA2, HOOC-COOH) within irradiated MA2 droplets and the appearance of glyoxylic acid (GlyA, HCOCOOH) in NaCl containing droplets. The photolysis process exerts a marked effect on the hygroscopic properties of the particles, resulting in a shift in deliquescence transitions toward higher relative humidity (RH) values. This study contributes to the understanding of the intricate physicochemical processes involved in SSA during their atmospheric transport. Likewise, this work sheds light on the impacts of these types of aerosols on cloud formation and climate change.

Assessment of Prickly Pear Fruit Peel Mucilage in Form of Gel as a Green Coagulant for the Tertiary Treatment of Domestic Wastewater.

The application of natural coagulants derived from food byproducts in domestic wastewater tertiary treatment, which contains a number of impurities as suspended colloidal particles, has a potential use as essential substitutes for traditional inorganic coagulants. These biomaterials are a sustainable and environmentally friendly alternative that can be used to improve water quality and human health. In this study, prickly pear (PP) fruit peel mucilage gel was evaluated as a novel coagulant for the tertiary stage of domestic wastewater treatment. Jar tests were performed on residual raw water at the inlet (influent) and outlet (effluent) of the tertiary wastewater treatment (constructed wetland) with a coagulant dose of 12 mg L-1 at a pH of 13. The efficiency of green (i.e., mucilage) and inorganic chemical (i.e., FeCl3) coagulants was compared on the basis of turbidity and color removal. The flocs produced by the coagulants were characterized structurally by FTIR spectroscopy and Zeta potential analysis and morphologically by scanning electron microscopy (SEM). The results showed that the turbidity and the color removal efficiency of the mucilage compared to the FeCl3 at the outlet of the treatment (effluent) were practically the same, reaching 94% turbidity and 85-87% color removal efficiency with both coagulants. The structure and morphology of the flocs generated by the coagulants showed a higher content of organic matter trapped in the flocs. The floc formation observed mechanisms were adsorption/bridging for mucilage and charge neutralization for FeCl3. The results of this study demonstrated that the PP mucilage green coagulant can be used to enhance the quality of treatment of domestic wastewater in an eco-friendly and biodegradable manner.

Microencapsulation of Betaxanthin Pigments from Pitahaya (Hylocereus megalanthus) By-Products: Characterization, Food Application, Stability, and In Vitro Gastrointestinal Digestion.

The yellow pitahaya peels generated as by-products during the consumption and processing of the fresh fruit are a rich and underutilized source of betaxanthins (natural yellow-orange pigment with antioxidant activity) and mucilage (structuring material used in the spray-drying process), molecules of high interest for the food industry. In this work, the betaxanthin-rich extract (BRE) obtained from this by-product was microencapsulated by spray drying (SD) using pitahaya peel mucilage (MPP) and maltodextrin (MD) as wall materials. Both types of microencapsulates (i.e., SD-MPP and SD-MD) retained high betaxanthin content (as measured by UV-vis) and antioxidant activity (ORAC). These microencapsulates were characterized structurally (FTIR and zeta potential), morphologically (SEM and particle size/polydispersity index), and thermally (DSC/TGA). The powdered microencapsulates were incorporated into the formulation of candy gummies as a food model, which were subjected to an in vitro gastrointestinal digestion process. The characterization study (FTIR and antioxidant activity) of the microcapsules showed that the fruit peel mucilage favors the retention of betaxanthins, while the SEM analysis revealed a particle size of multimodal distribution and heterogeneous morphology. The addition of SD-MPP microcapsules in the candy gummy formulation favored the total dietary fiber content as well as the gumminess and chewiness of the food matrix; however, the inhibition of AAPH• (%) was affected. The stability of the yellow color in the gummies after 30 days of storage indicates its suitability for storage. Consequently, the microencapsulation of betaxanthins with pitahaya peel mucilage can be used as a food additive colorant in the food industry, replacing synthetic colorants, to develop products with beneficial qualities for health that can satisfy the growing demand of consumers.

Spray-Drying Microencapsulation of Andean Blueberry (Vaccinium meridionale Sw.) Anthocyanins Using Prickly Pear (Opuntia ficus indica L.) Peel Mucilage or Gum Arabic: A Comparative Study.

The recovery of byproducts from the food industry is a promising approach to obtain hydrophilic biopolymers with potential health benefits. In this work, the mucilage obtained from the peel of the Opuntia ficus-indica (OFI) fruit was compared with gum arabic (GA) as wall materials for the microencapsulation of Colombian blueberry anthocyanins, using the spray-drying process. For both types of microencapsulates, the following were determined: anthocyanin content (UV-vis and HPLC/MS-MS), total dietary content (enzymatic-gravimetric method), antioxidant activity (ORAC), color (CIELab parameters), morphology (SEM and particle size), and thermal behavior (DSC/TGA). Six different anthocyanins were identified by HPLC/MS-MS in the non-lyophilized Andean blueberry sample (LABP) and in the OFI-mucilage and GA microcapsules. OFI mucilage, compared to GA, favors the formation of larger spherical particles, a smoother surface without cracks, and greater thermal stability. The higher anthocyanin retention capacity in OFI microcapsules leads to higher antioxidant capacity and red coloration for this biomaterial. Consequently, the microencapsulation of anthocyanins with mucilage from the peel of the OFI fruit is proposed as a promising alternative for the protection and incorporation of this natural dye with high antioxidant capacity and dietary fiber content in new functional food/cosmetic formulations, while giving added value to the natural byproducts of OFI.

Mucilage from Yellow Pitahaya (Selenicereus megalanthus) Fruit Peel: Extraction, Proximal Analysis, and Molecular Characterization.

Mucilage is a hydrophilic biopolymeric material of interest in the food industry due to its high content of dietary fiber, antioxidant activity, and gelling and thickening capacities, which is present in high concentration in agricultural by-products, such as the peel of cacti fruits. In this work, the powdered mucilage extracted from the peel of yellow pitahaya (Selenicereus megalanthus) fruit was characterized using a multi-technical approach that included proximal analysis (proteins, lipids, crude fiber, ash, and carbohydrates), as well as structural (FTIR, NMR, UPLC-QTOF-MS, and X-ray diffraction), colorimetric (CIELab parameters), morphological (SEM), and thermal (DSC/TGA) methods. Likewise, its total content of dietary fiber and polyphenols, as well as its antioxidant activity, were determined. This dried mucilage presented a light pale yellow-reddish color, attributed to the presence of betalains (bioactive pigments with high antioxidant activity). The FTIR spectrum revealed functional groups associated with a low presence of proteins (5.45 ± 0.04%) and a high concentration of oligosaccharides (55.26 ± 0.10%). A zeta potential of -29.90 ± 0.90 mV was determined, denoting an anionic nature that favors the use of this mucilage as a stable colloidal dispersion. UPLC-QTOF-MS analysis revealed a major oligosaccharide composition based on galacturonic acid units in anionic form. SEM micrographs revealed a cracked morphology composed of amorphous and irregular particles. According to the DSC/TGA results, this mucilage can be introduced as a new source of hydrocolloids in food processes since it has high thermal stability that has been manifested up to 373.87 °C. In addition, this biopolymer exhibited a high content of polyphenols (25.00 ± 0.01-g gallic acid equivalent (GAE)/100-g sample), dietary fiber (70.51%), and antioxidant activity (1.57 ± 0.01 mmol Trolox equivalents/kg of sample). It was concluded that this mucilaginous material presents sufficient physicochemical and functional conditions to be used as a nutritional ingredient, thus giving valorization to this agricultural by-product.

Use of Opuntia ficus-indica Fruit Peel as a Novel Source of Mucilage with Coagulant Physicochemical/Molecular Characteristics.

The peels obtained as a byproduct from the processing of fruits (prickly pears) of the Cactaceae family are a rich source of mucilage, a hydrocolloid biopolymer that may have potential application in water/wastewater treatment as a natural coagulant. In this study, the structural (UPLC-QTOF-MS, FTIR, Raman, NMR, XRD, and zeta potential), morphological (SEM), and thermal (DSC/TGA) characterizations of the mucilage extracted from the peels of Opuntia ficus-indica (OFI) fruits were carried out. UPLC-QTOF-MS results revealed the presence of a branched polymer with an average molecular weight of 0.44 KDa for this mucilage in aqua media. The NMR spectra of mucilage in DMSO-d6 indicated that it seemed well-suited as a coagulant with its typical oligosaccharide structure. FTIR studies confirmed the presence of hydroxyl and carboxyl functional groups in the mucilage, indicating its polyelectrolyte nature that could provide coagulating properties through binding and adsorption mechanisms. Likewise, the zeta potential of -23.63 ± 0.55 mV showed an anionic nature of the mucilage. Power XRD technique evidenced the presence of crystalline poly(glycine-ß-alanine), glutamic acid, and syn-whewellite. SEM images revealed an irregular and amorphous morphology with cracks, which are suitable characteristics for adsorption mechanisms. The mucilage exhibited two endothermic transitions, with a decomposition temperature in uronic acid of 423.10 °C. These findings revealed that mucilage obtained from OFI fruit peels has molecular and physicochemical characteristics that are suited to its possible application as a natural coagulant in water/wastewater treatments.

Evaluation of Guava Pulp Microencapsulated in Mucilage of Aloe Vera and Opuntia ficus-indica as a Natural Dye for Yogurt: Functional Characterization and Color Stability.

The substitution of artificial colorants for pigments extracted from fruits is a highly desirable strategy in the food industry for the manufacture of natural, functional, and safe products. In this work, a 100% natural spray-dried (SD) microencapsulated colorant of pink guava pulp, using aloe vera (AV) or Opuntia ficus-indica (OFI) mucilage as functional encapsulating material, was prepared and evaluated as an additive into a yogurt (Y) matrix. The characterization of yogurt samples supplemented with OFI (Y-SD-OFI) and AV (Y-SD-AV) mucilage-covered guava pulp microcapsules was carried out through carotenoid quantification using UV-vis and HPLC-MS techniques, dietary fiber content, antioxidant capacity, colorimetry, and textural analysis, as well as by an evaluation of color stability after 25 days of storage at 4 °C in the dark. These physicochemical characteristics and color stability on the Y-SD-OFI and Y-SD-AV samples were compared with those of a commercial yogurt (control sample, Y-C) containing sunset yellow FCF synthetic colorant (E110). Y-SD-OFI and Y-SD-AV samples exhibited a high content of lycopene, dietary fiber, and antioxidant activity, which were absent in the control sample. Microencapsulated lycopene imparted a highly stable color to yogurt, contrary to the effect provided by the E110 dye in the control sample. The texture profile analysis revealed an increase in firmness, consistency, and cohesion in the Y-SD-OFI sample, contrary to the Y-SD-AV and Y-C samples, which was attributed to the variation in fiber concentration in the microcapsules. The incorporation of OFI and AV mucilage microparticles containing pink guava pulp into yogurt demonstrated its potential application as a functional natural colorant for dairy products.

In Silico Antiprotozoal Evaluation of 1,4-Naphthoquinone Derivatives against Chagas and Leishmaniasis Diseases Using QSAR, Molecular Docking, and ADME Approaches.

Chagas and leishmaniasis are two neglected diseases considered as public health problems worldwide, for which there is no effective, low-cost, and low-toxicity treatment for the host. Naphthoquinones are ligands with redox properties involved in oxidative biological processes with a wide variety of activities, including antiparasitic. In this work, in silico methods of quantitative structure-activity relationship (QSAR), molecular docking, and calculation of ADME (absorption, distribution, metabolism, and excretion) properties were used to evaluate naphthoquinone derivatives with unknown antiprotozoal activity. QSAR models were developed for predicting antiparasitic activity against Trypanosoma cruzi, Leishmania amazonensis, and Leishmania infatum, as well as the QSAR model for toxicity activity. Most of the evaluated ligands presented high antiparasitic activity. According to the docking results, the family of triazole derivatives presented the best affinity with the different macromolecular targets. The ADME results showed that most of the evaluated compounds present adequate conditions to be administered orally. Naphthoquinone derivatives show good biological activity results, depending on the substituents attached to the quinone ring, and perhaps the potential to be converted into drugs or starting molecules.

Spray-Drying Microencapsulation of Pink Guava (Psidium guajava) Carotenoids Using Mucilage from Opuntia ficus-indica Cladodes and Aloe Vera Leaves as Encapsulating Materials.

In this work, the capacity of the mucilage extracted from the cladodes of Opuntia ficus-indica (OFI) and aloe vera (AV) leaves as wall material in the microencapsulation of pink guava carotenoids using spray-drying was studied. The stability of the encapsulated carotenoids was quantified using UV-vis and HPLC/MS techniques. Likewise, the antioxidant activity (TEAC), color (CIELab), structural (FTIR) and microstructural (SEM and particle size) properties, as well as the total dietary content, of both types of mucilage microcapsules were determined. Our results show that the use of AV mucilage, compared to OFI mucilage, increased both the retention of ß-carotene and the antioxidant capacity of the carotenoid microcapsules by around 14%, as well as the total carotenoid content (TCC) by around 26%, and also favors the formation of spherical-type particles (Ø â‰… 26 µm) without the apparent damage of a more uniform size and with an attractive red-yellow hue. This type of microcapsules is proposed as a convenient alternative means to incorporate guava carotenoids, a natural colorant with a high antioxidant capacity, and dietary fiber content in the manufacture of functional products, which is a topic of interest for the food, pharmaceutical, and cosmetic industries.

Evaluation of Turbidity and Color Removal in Water Treatment: A Comparative Study between Opuntia ficus-indica Fruit Peel Mucilage and FeCl3.

Natural coagulants derived from by-products have gained popularity as sustainable alternatives to inorganic coagulants in water/wastewater treatment due to their abundant availability, biodegradability, low cost, easy disposal and low sludge volumes. In this study, the mucilage obtained from the peel of Opuntia ficus-indica fruit was evaluated as a biocoagulant for treating synthetic turbid water and compared with a traditional chemical coagulant (FeCl3). The effects of coagulant dosage and pH on the turbidity and color-removal efficiency of synthetic turbid water were analyzed. To estimate the coagulation mechanism, the flocs produced under optimal values were characterized structurally (FTIR and zeta potential) and morphologically (SEM). The optimal condition for the removal of turbidity and color was a coagulant dose of 12 mg/L at pH 13. For the optimal values, the biocoagulant and the FeCl3 presented a maximum removal of 82.7 ± 3.28% and 94.63 ± 0.98% for turbidity and 71.82 ± 2.72% and 79.94 ± 1.77% for color, respectively. The structure and morphology of the flocs revealed that the coagulation mechanism of the mucilage was adsorption and bridging, whereas that of FeCl3 was charge neutralization. The results obtained showed that the mucilage could be used as an alternative coagulant to replace FeCl3.

Synthesis, Structural Characterization, and In Vitro and In Silico Antifungal Evaluation of Azo-Azomethine Pyrazoles (PhN2(PhOH)CHN(C3N2(CH3)3)PhR, R = H or NO2).

The azo-azomethine imines, R1-N=N-R2-CH=N-R3, are a class of active pharmacological ligands that have been prominent antifungal, antibacterial, and antitumor agents. In this study, four new azo-azomethines, R1 = Ph, R2 = phenol, and R3 = pyrazol-Ph-R' (R = H or NO2), have been synthesized, structurally characterized using X-ray, IR, NMR and UV-Vis techniques, and their antifungal activity evaluated against certified strains of Candida albicans and Cryptococcus neoformans. The antifungal tests revealed a high to moderate inhibitory activity towards both strains, which is regulated as a function of both the presence and the location of the nitro group in the aromatic ring of the series. These biological assays were further complemented with molecular docking studies against three different molecular targets from each fungus strain. Molecular dynamics simulations and binding free energy calculations were performed on the two best molecular docking results for each fungus strain. Better affinity for active sites for nitro compounds at the "meta" and "para" positions was found, making them promising building blocks for the development of new Schiff bases with high antifungal activity.

Antiprotozoal QSAR modelling for trypanosomiasis (Chagas disease) based on thiosemicarbazone and thiazole derivatives.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, remains a neglected endemic infection that affects around 8 million people worldwide and causes 12,000 premature deaths per year. Traditional chemotherapy is limited to the nitro-antiparasitic drugs Benznidazole and Nifurtimox, which present serious side effects and low long-term efficacy. Several research efforts have been made over the last decade to find new chemical structures with better effectiveness and tolerance than standard anti-Chagas drugs. Among these, new sets of thiosemicarbazone and thiazole derivatives have exhibited potent in vitro activity against T. cruzi, especially for its extracellular forms (epimastigote and trypomastigote). In this work, we have developed three antiprotozoal quantitative structure-relationship (QSAR) models for Chagas disease based on the in vitro activity data reported as IC50 (µM) and CC50 (µM) over the last decade, particularly by Lima-Leite's group in Brazil. The models were developed using the replacement method (RM), a technique based on Multivariable Linear Regression (MLR), and external and internal validation methodologies, like the use of a test set, Leave-one-Out (LOO) cross-validation and Y-Randomization. Two of these QSAR models were developed for trypomastigotes form of the parasite Trypanosoma cruzi, one based on IC50 and the other on CC50 data; while the third QSAR model was developed for its epimastigotes form based on CC50 activity. Our models presented sound statistical parameters that endorses their prediction capability. Such capability was tested for a set of 13 hitherto-unknown structurally related aromatic cyclohexanone derivatives.

Encapsulation Effect on the In Vitro Bioaccessibility of Sacha Inchi Oil (Plukenetia volubilis L.) by Soft Capsules Composed of Gelatin and Cactus Mucilage Biopolymers.

Sacha inchi (Plukenetia volubilis L.) seed oil is a rich source of polyunsaturated fatty acids (PUFAs) that are beneficial for human health, whose nutritional efficacy is limited because of its low water solubility and labile bioaccessibility (compositional integrity). In this work, the encapsulation effect, using blended softgels of gelatin (G) and cactus mucilage (CM) biopolymers, on the PUFAs' bioaccessibility of P. volubilis seed oil was evaluated during in vitro simulated digestive processes (mouth, gastric, and intestinal). Gas chromatography-mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID) were used for determining the chemical composition of P. volubilis seed oil both before and after in vitro digestion. The most abundant compounds in the undigested samples were α-linolenic, linoleic, and oleic acids with 59.23, 33.46, and 0.57 (g/100 g), respectively. The bioaccessibility of α-linolenic, linoleic, and oleic acid was found to be 1.70%, 1.46%, and 35.8%, respectively, along with the presence of some oxidation products. G/CM soft capsules are capable of limiting the in vitro bioaccessibility of PUFAs because of the low mucilage ratio in their matrix, which influences the enzymatic hydrolysis of gelatin, thus increasing the release of the polyunsaturated content during the simulated digestion.

Crystal structure, spectroscopic characterization and Hirshfeld surface analysis of aqua-dichlorido-{N-[(pyridin-2-yl)methyl-idene]aniline}copper(II) monohydrate.

The reaction of N-phenyl-1-(pyridin-2-yl)methanimine with copper chloride dihydrate produced the title neutral complex, [CuCl2(C12H10N2)(H2O)]·H2O. The CuII ion is five-coordinated in a distorted square-pyramidal geometry, in which the two N atoms of the bidentate Schiff base, as well as one chloro and a water mol-ecule, form the irregular base of the pyramidal structure. Meanwhile, the apical chloride ligand inter-acts through a strong hydrogen bond with a water mol-ecule of crystallization. In the crystal, mol-ecules are arranged in pairs, forming a stacking of symmetrical cyclic dimers that inter-act in turn through strong hydrogen bonds between the chloride ligands and both the coordinated and the crystallization water mol-ecules. The mol-ecular and electronic structures of the complex were also studied in detail using EPR (continuous and pulsed), FT-IR and Raman spectroscopy, as well as magnetization measurements. Likewise, Hirshfeld surface analysis was used to investigate the inter-molecular inter-actions in the crystal packing.

1,4-Dithiolbenzene, 1,4-dimethanediolbenzene and 4-thioacetylbiphenyl molecular systems: electronic devices with possible applications in molecular electronics.

A theoretical study of the electronic transport properties of the 1,4-dithiolbenzene, 1,4-dimethanediolbenzene and 4-thioacetylbiphenyl molecules coupled to two metal contacts is carried out. The tight binding Hamiltonian approximation is applied to describe each of the molecular systems using the real space renormalization analytical method. Using Green's functions with the Landauer formalism, the transmission probability, current, shot noise and Fano factor of these three systems are calculated and analyzed in order to identify their behavior as insulators, semiconductors, or conductors, and their possible applications, such as quantum wires. The theoretical results are compared with experimental results that have been reported in the literature. The results indicate a high concordance between the results obtained by the proposed method and the experimental results.

Enhancing Double-Beam Laser Tweezers Raman Spectroscopy (LTRS) for the Photochemical Study of Individual Airborne Microdroplets.

A new device and methodology for vertically coupling confocal Raman microscopy with optical tweezers for the in situ physico- and photochemical studies of individual microdroplets (Ø ≤ 10 µm) levitated in air is presented. The coupling expands the spectrum of studies performed with individual particles using laser tweezers Raman spectroscopy (LTRS) to photochemical processes and spatially resolved Raman microspectroscopy on airborne aerosols. This is the first study to demonstrate photochemical studies and Raman mapping on optically levitated droplets. By using this configuration, photochemical reactions in aerosols of atmospheric interest can be studied on a laboratory scale under realistic conditions of gas-phase composition and relative humidity. Likewise, the distribution of photoproducts within the drop can also be observed with this setup. The applicability of the coupling system was tested by studying the photochemical behavior of microdroplets (5 µm < Ø < 8 µm) containing an aqueous solution of sodium nitrate levitated in air and exposed to narrowed UV radiation (254 ± 25 nm). Photolysis of the levitated NaNO3 microdroplets presented photochemical kinetic differences in comparison with larger NaNO3 droplets (40 µm < Ø < 80 µm), previously photolyzed using acoustic traps, and heterogeneity in the distribution of the photoproducts within the drop.

Preparation and Physicochemical Characterization of Softgels Cross-Linked with Cactus Mucilage Extracted from Cladodes of Opuntia Ficus-Indica.

A new crosslinking formulation using gelatin (G) and cactus mucilage (CM) biopolymers was developed, physicochemically characterized and proposed as an alternative wall material to traditional gelatin capsules (softgels). The effect of G concentration at different G/CM ratios (3:1, 1:1 and 1:3) was analyzed. Transparency, moisture content (MC), solubility in water (SW), morphology (scanning electron microscopy, SEM), vibrational characterization (Fourier transform infrared, FTIR), color parameters (CIELab) and thermal (differential scanning calorimetry/thermogravimetric analysis, DSC/TGA) properties of the prepared composite (CMC) capsules were estimated and compared with control (CC) capsules containing only G and glycerol. In addition, the dietary fiber (DF) content was also evaluated. Our results showed that the transparency of composite samples decreased gradually with the presence of CM, the G/CM ratio of 3:1 being suitable to form the softgels. The addition of CM decreased the MC, the SW and the lightness of the capsules. Furthermore, the presence of polysaccharide had significant effects on the morphology and thermal behavior of CMC in contrast to CC. FTIR spectra confirmed the CMC formation by crosslinking between CM and G biopolymers. The addition of CM to the softgels formulation influenced the DF content. Our findings support the feasibility of developing softgels using a formulation of CM and G as wall material with nutritional properties.

Current's Fluctuations through Molecular Wires Composed of Thiophene Rings.

We study theoretically the electronic transport and quantum fluctuations in single-molecule systems using thiophene rings as integrated elementary functions, as well as the dependence of these properties with the increase of the coupled rings, i.e., as a quantum wire. In order to analyze the current flow through these molecular systems, the thiophene rings are considered to be connected to metal contacts, which, in general terms, will be related to the application of voltages (bias voltages or gate voltages) to generate non-equilibrium behavior between the contacts. Due to the nonlinear behavior that is generated when said voltages are applied, it is possible to observe quantum fluctuations in the transport properties of these molecular wires. For the calculation of the transport properties, we applied a tight-binding approach using the Landauer-Büttiker formalism and the Fischer-Lee relationship, by means of a semi-analytic Green's function method within a real-space renormalization (decimation procedure). Our results showed an excellent agreement with results using a tight-binding model with a minimal number of parameters reported so far for these molecular systems.

Photochemical Reaction of OCSe with ClF in Argon Matrix: A Light-Driven Formation of XC(O)SeY (X, Y = F or Cl) Species.

The photochemistry of OCSe with ClF trapped together in argon matrices at cryogenic temperatures has been explored and the first interhalogen representatives of the elusive XC(O)SeY family, namely syn-ClC(O)SeF, anti-ClC(O)SeF, syn-FC(O)SeCl, and anti-FC(O)SeCl, as well as the hitherto triatomic species ClSeF complexed by a CO molecule, were obtained. Both ClC(O)SeF conformers appear to be produced independently by photolysis of the respective precursors; while formation of both FC(O)SeCl structures is ruled by the presence of an angular molecular complex OCSe···Cl-F formed prior to photolysis. This latter photochemical pathway seems to favor the formation of the less stable anti-FC(O)SeCl structure instead of the more stable syn- one. With the aid of quantum chemical calculations, using ab initio, DFT, TDDFT, and CASSCF methods, the mechanism for this photochemical reaction is rationalized both in terms of radical processes as well as a photoinduced electron transfer occurring into the OCSe···Cl-F complex. Also a singlet-triplet conical intersection between anti and syn rotamers of the FC(O)SeCl molecule is theoretically explored.