Catalytic Transfer Hydrogenation and Acid Reactions of Furfural and 5-(Hydroxymethyl)furfural over Hf-TUD-1 Type Catalysts

Heterogeneous catalysis, which has served well the petrochemical industry, may valuably contribute towards a bio-based economy by sustainably enabling selective reactions to renewable chemicals. Carbohydrate-containing matter may be obtained from various widespread sources and selectively converted to furanic platform chemicals: furfural (Fur) and 5-(hydroxymethyl)furfural (Hmf). Valuable bioproducts may be obtained from these aldehydes via catalytic transfer hydrogenation (CTH) using alcohols as H-donors under relatively moderate reaction conditions. Hafnium-containing TUD-1 type catalysts were the first of ordered mesoporous silicates explored for the conversion of Fur and Hmf via CTH/alcohol strategies. The materials promoted CTH and acid reactions leading to the furanic ethers. The bioproducts spectrum was broader for the reaction of Fur than of Hmf. A Fur reaction mechanism based on literature data was discussed and supported by kinetic modelling. The influence of the Hf loading and reaction conditions (catalyst load, type of alcohol H-donor, temperature, initial substrate concentration) on the reaction kinetics was studied. The reaction conditions were optimized to maximize the yields of 2-(alkoxymethyl)furan ethers formed from Fur; up to 63% yield was reached at 88% Fur conversion, 4 h/150 °C, using Hf-TUD-1(75), which was a stable catalyst. The Hf-TUD-1(x) catalysts promoted the selective conversion of Hmf to bis(2-alkoxymethyl)furan; e.g., 96% selectivity at 98% Hmf conversion, 3 h/170 °C for Hf-TUD-1(50).     

Physicochemical Characterization and Paper Spray Mass Spectrometry Analysis of Myrciaria Floribunda (H. West ex Willd.) O. Berg Accessions

Myrciaria floribunda, also known as rumberry, is a tree native to the Brazilian Atlantic Forest, where its fruits have the potential for commercial use. This study evaluates the antioxidant potential, determines the phytochemical profile, and chemically characterizes the rumberry fruit. Accessions were sampled from the Rumberry Active Germplasm Bank of the Federal University of Alagoas, Brazil. Physical characteristics, chemical characteristics, and phenolic compound content were analyzed. Chemical profile characterization was carried out using PSMS. Accessions had an average weight of 0.86 g. Accession AC137 presented a higher pulp yield (1.12 g). AC132 and AC156 had larger fruits, AC137 showed greater firmness (5.93 N), and AC160 had a higher and total phenolic content ratio (279.01 ± 11.11). Orange-colored accessions scored higher in evaluated parameters, except for AC160 for phenolic content. Thirty-two compounds were identified on positive ionization mode and 42 compounds on negative ionization mode using PSMS. Flavonoids, followed by the derivatives of benzoic acid, sugars, and phenylpropanoids, were the most prominent. Myricitrin, quercitrin, and catechin stand out as flavonoids that have been reported in previous studies with antioxidant and antimicrobial properties, in addition to health and therapeutical benefits, demonstrating the potential of the rumberry fruit.     

Effects of Prenatal Exposure to Aflatoxin B1: A Review

Aflatoxins are mycotoxins produced as secondary fungal metabolites. Among them, aflatoxin B1 (AFB1) stands out due to its genotoxic and mutagenic potential, being a potent initiator of carcinogenesis. In this review, the outcomes from the published literature in the past 10 years on the effects of AFB1 pathophysiological mechanisms on embryological and fetal development are discussed. In several animal species, including humans, AFB1 has a teratogenic effect_, resulting in bone malformations, visceral anomalies, lesions in several organs, and behavioral and reproductive changes, in addition to low birth weight. The mutagenic capacity of AFB1 in prenatal life is greater than in adults, indicating that when exposure occurs in the womb, the risk of the development of neoplasms is higher. Studies conducted in humans indicate that the exposure to this mycotoxin during pregnancy is associated with low birth weight, decreased head circumference, and DNA hypermethylation. However, as the actual impacts on humans are still unclear, the importance of this issue cannot be overemphasized and studies on the matter are essential.     

Enhancement of Antibiotic Activity by 1,8-Naphthyridine Derivatives against Multi-Resistant Bacterial Strains

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains.     

Gear shifting multi-objective optimization to improve vehicle performance,fuel consumption,and engine emissions

In the present work, the Adaptive-Weight Genetic Algorithm was employed in order to determine the gear shifting strategies that allow an automobile to work in the best compromise among fuel consumption, engine emissions, and vehicle performance. For the assessment of each of the three objective functions, a simulation model based on engine data and on the well-established equations of the longitudinal dynamics was developed. The driving cycle chosen for the calculations was the FTP-75, which takes into account both cold and hot starts, meaning that the transient operation during the warm-up of the catalyst is also considered.     

SOLEIL shining on the solution‐state structure of biomacromolecules by synchrotron X‐ray footprinting at the Metrology beamline

Synchrotron X‐ray footprinting complements the techniques commonly used to define the structure of molecules such as crystallography, small‐angle X‐ray scattering and nuclear magnetic resonance. It is remarkably useful in probing the structure and interactions of proteins with lipids, nucleic acids or with other proteins in solution, often better reflecting the in vivo state dynamics. To date, most X‐ray footprinting studies have been carried out at the National Synchrotron Light Source, USA, and at the European Synchrotron Radiation Facility in Grenoble, France. This work presents X‐ray footprinting of biomolecules performed for the first time at the X‐ray Metrology beamline at the SOLEIL synchrotron radiation source. The installation at this beamline of a stopped‐flow apparatus for sample delivery, an irradiation capillary and an automatic sample collector enabled the X‐ray footprinting study of the structure of the soluble protein factor H (FH) from the human complement system as well as of the lipid‐associated hydrophobic protein S3 oleosin from plant seed. Mass spectrometry analysis showed that the structural integrity of both proteins was not affected by the short exposition to the oxygen radicals produced during the irradiation. Irradiated molecules were subsequently analysed using high‐resolution mass spectrometry to identify and locate oxidized amino acids. Moreover, the analyses of FH in its free state and in complex with complement C3b protein have allowed us to create a map of reactive solvent‐exposed residues on the surface of FH and to observe the changes in oxidation of FH residues upon C3b binding. Studies of the solvent accessibility of the S3 oleosin show that X‐ray footprinting offers also a unique approach to studying the structure of proteins embedded within membranes or lipid bodies. All the biomolecular applications reported herein demonstrate that the Metrology beamline at SOLEIL can be successfully used for synchrotron X‐ray footprinting of biomolecules.     

Design and Synthesis In Silico Drug-like Prediction and Pharmacological Evaluation of Cyclopolymethylenic Homologous of LASSBio-1514

Acylhydrazones are still an important framework to the design of new bioactive compounds. As treatment of chronic pain represents a clinical challenge, we decided to modify the structure of LASSBio-1514 (1), previously described as anti-inflammatory and analgesic prototype. Applying the homologation as a strategy for molecular modification, we designed a series of cyclopentyl- (2a–e), cyclobutyl- (3a–e), and cyclopropylacylhydrazones (4a–e) that were synthetized and evaluated in murine models of inflammation and pain. A comparison of their in silico physicochemical and drug-like profile was conducted, as well as their anti-inflammatory and analgesic effect. Compounds 4a (LASSBio-1755) and 4e (LASSBio-1757) displayed excellent in silico drug-like profiles and were identified as new analgesic lead-candidates in acute and chronic model of pain, through oral administration.     

Co-Treatment of Purified Annatto Oil (Bixa orellana L.) and Its Granules (Chronic®) Improves the Blood Lipid Profile and Bone Protective Effects of Testosterone in the Orchiectomy-Induced Osteoporosis in Wistar Rats

This study aimed to evaluate and compare the effects of co-treatment with purified annatto oil (PAO) or its granules (GRA, Chronic^®) with that of testosterone on the orchiectomy-induced osteoporosis in Wistar rats. After surgery, rats were treated from day 7 until day 45 with testosterone only (TES, 7 mg/kg, IM) or TES + PAO or GRA (200 mg/kg, p.o.). The following parameters were evaluated: food/water intake, weight, HDL, LDL, glucose, triglycerides (TG), total cholesterol (TC), alkaline phosphatase levels, blood phosphorus and calcium contents, femur weight, structure (through scanning electron microscopy), and calcium content (through atomic absorption spectrophotometry). Our results show that orchiectomy could significantly change the blood lipid profile and decrease bone integrity parameters. Testosterone reposition alone could improve some endpoints, including LDL, TC, bone weight, and bone calcium concentration. However, other parameters were not significantly improved. Co-treatment with PAO or GRA improved the blood lipid profile and bone integrity more significantly and improved some endpoints not affected by testosterone reposition alone (such as TG levels and trabeculae sizes). The results suggest that co-treatment with annatto products improved the blood lipid profile and the anti-osteoporosis effects of testosterone. Overall, GRA had better results than PAO.     

Magnetic properties of (Ce1−xLax)PdIn2

We report on results of X-ray powder diffraction, magnetization and specific heat measurements of the pseudo-ternary (Ce_1−xLa_x)PdIn₂ system with x=0; 0.2; 0.4 and 0.6. The results show a linear increase of the unit cell volume and a reduction of the ferromagnetic transition as La content increases. The Debye temperature, Sommerfeld coefficient and crystal field parameters were estimated from specific heat data, and are found to be weakly dependent of the Ce concentration. Also, the variation of magnetic entropy at T_C is only weakly dependent on x (ΔS≅0.92Rln2) indicating that T_K/T_C is approximately constant along the series. The T_C and T_K behaviors are explained by the variation of the exchange parameter due to the volume change when Ce is replaced by La. Our results indicate that the chemical pressure is the dominant effect rather than the chemical disorder for determining the physical proprieties of the (Ce_1−xLa_x)PdIn₂ system.     

Effects of strontium and calcium simultaneous substitution on electrical and structural properties of Pb1?x?yCaxSryTiO3 thin films

Ferroelectric Pb_1−x−y Ca _x Sr _y TiO₃ thin films (denoted by PCST90, PCST70, and PCST30) were deposited on the Pt/Ti/SiO₂/Si substrates by a chemical solution deposition method. Their properties were investigated from the viewpoint of crystal structure, microstructure, dielectric, and ferroelectric properties. X-ray diffraction patterns revealed the formation of PCST90, PCST70, and PCST30 thin films without any secondary phases. Infrared and Raman spectroscopy results show that a gradual phase transition from tetragonal to pseudocubic or cubic perovskite structure may occur in PCST thin films with the simultaneous increase of Ca²⁺ and Sr²⁺ contents. Both substitution of isovalent Ca²⁺ and Sr²⁺ at Pb²⁺-site enhanced the dielectric constant and reduced the remnant polarization. In addition, ferroelectric test analyses show that the PCST thin films undergo a ferroelectric-to-paraelectric phase transformation with an amount of Pb²⁺, Ca²⁺, and Sr²⁺ at 30%, 35%, and 35% mol, respectively. Hence, the absence of ferroelectric property may be attributed to a decreasing of the octahedron distortion in the perovskite structure accompanied by a weakening of long-range ferroelectric order.