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991.
992.
993.
Olga I. Tarzi Luciano Di Stéfano Juan E. Argüello Gabriela Oksdath‐Mansilla Rosa Erra‐Balsells 《Photochemistry and photobiology》2013,89(6):1368-1374
2,4‐, 2,5‐, 2,6‐ and 3,5‐dihydroxyacetophenone (DHA) used as matrices in matrix‐assisted ultraviolet laser desorption/ionization mass spectrometry (UV‐MALDI‐MS) were studied by steady‐state and transient absorption spectroscopy, together with DFT calculations at the B3LYP level of theory. All compounds have low fluorescence quantum yields, possibly due to an efficient excited‐state intramolecular proton transfer (ESIPT). Laser flash photolysis (LFP) results showed that, only for 2,4‐DHA, a phototautomer could be detected at λ = 400 nm. Their photochemical stability in solution at different wavelengths and conditions was analyzed by UV–Vis and 1H nuclear magnetic resonance spectroscopy (1H‐NMR), together with thin layer chromatography and ultraviolet laser desorption/ionization mass spectrometry (UV‐LDI‐MS). Only 3,5‐DHA showed decomposition when irradiated, probably because phototautomerization is not possible. Thermal stability studies of these compounds in solid state were also conducted. 相似文献
994.
Loredana Elena Nita Aurica P. Chiriac Alina Gabriela Rusu Alina Ghilan Raluca P. Dumitriu Maria Bercea Nita Tudorachi 《Macromolecular bioscience》2020,20(4)
The purpose of the study is to obtain multicomponent polyelectrolyte hydrogels with optimal synergistic properties by combining a modified starch with a synthetic one. Thus, new low‐cost and biocompatible semi‐interpenetrating polymer network (semi‐IPN) hydrogels of carboxymethyl starch and poly(2‐dimethylaminoethyl methacrylate) are prepared and investigated. The synthesized hydrogels are studied with respect to the specific characteristics of the gels: swelling kinetics, thermal analysis, viscoelastic characteristics, and their ability to be used as a matrix in drug delivery systems. Therefore, the semi‐IPN gels are loaded with ibuprofen, followed by additional tests to assess the in vitro drug release. The cytocompatibility of the hydrogels with respect to their composition is evaluated in vitro on fibroblast cell culture. The investigations confirm the obtainment of new semi‐IPN hydrogels with pH and temperature responsiveness, good mechanical strength, and potential for use as drug delivery systems or transdermal patches. 相似文献
995.
Prof. Kenneth K. Laali Angela T. Zwarycz Nicholas Beck Dr. Gabriela L. Borosky Dr. Manabu Nukaya Prof. Gregory D. Kennedy 《ChemistryOpen》2020,9(8):822-834
In an effort to combine the anti-proliferative effect of CUR-BF2 and CUR compounds with anti-inflammatory benefits of non-steroidal anti-inflammatory drugs (NSAIDs), a library of the bis- and mono-NSAID/CUR-BF2 and NSAID/CUR conjugates were synthesized by coupling flufenamic acid, flurbiprofen, naproxen, indomethacin, and ibuprofen to diversely substituted hydroxy-benzaldehydes via an ester linkage, and by subsequent reaction with acetylacetone-BF2 to form the bis- and the mono-NSAID/CUR-BF2 adducts. Since conversion to NSAID/CUR by the previously developed decomplexation protocol showed limited success, a set of NSAID/CUR conjugates were independently prepared by directly coupling the NSAIDs with parent curcumin. The bis-NSAID/CUR-BF2 and bis-NSAID-CUR hybrids exhibited low cytotoxicity in NCI-60 assay, and in independent cell viability assay on colorectal cancer (CRC) cells (HCT116, HT29, DLD-1, RKO, SW837, CaCo2) and in normal CR cells (CCD841CoN). By contrast, the mono-naproxin and mono-flurbiprofen CUR-BF2 adducts exhibited remarkable anti-proliferative and apoptopic activity in NCI-60 assay most notably against HCT-116 (colon), OVCAR-3 (ovarian), and ACHN (renal) cells. Computational molecular docking calculations showed favorable binding energies to HER2, VEGFR2, BRAF, and Bcl-2 as well as to COX-1 and COX-2, which in several cases exceeded known inhibitors. The main interactions between the ligands and the proteins were hydrophobic, although several hydrogen bonds were also observed. A sub-set of six compounds that had exhibited little or no cytotoxicity were tested for their anti-inflammatory response with THP-1 human macrophages in comparison to parent NSAIDs or parent curcumin. 相似文献
996.
Gabriela Marcelino David Johane Machate Karine de Cssia Freitas Priscila Aiko Hiane Iriani Rodrigues Maldonade Arnildo Pott Marcel Arakaki Asato Camila Jordo Candido Rita de Cssia Avellaneda Guimares 《Molecules (Basel, Switzerland)》2020,25(24)
Carotenoids are vital antioxidants for plants and animals. They protect cells from oxidative events and act against the inflammatory process and carcinogenesis. Among the most abundant carotenoids in human and foods is β-carotene. This carotenoid has the highest level of provitamin A activity, as it splits into two molecules of retinol through the actions of the cytosolic enzymes: β-carotene-15,15′-monooxygenase (β-carotene-15,15′-oxygenase 1) and β-carotene-9′,10′-dioxygenase (β-carotene-9′,10′-oxygenase 2). The literature supports the idea that β-carotene acts against type 2 diabetes mellitus, cardiovascular diseases, obesity, and metabolic syndrome. Due to the many processes involved in β-carotene biosynthesis and metabolic function, little is known about such components, since many mechanisms have not yet been fully elucidated. Therefore, our study concisely described the relationships between the consumption of carotenoids, with emphasis on β-carotene, and obesity and type 2 diabetes mellitus and its associated parameters in order to understand the preventive role of carotenoids better and encourage their consumption. 相似文献
997.
Mariana G. Vallejo Marcos E. Corzo María Gabriela Ortega 《Natural product research》2020,34(9):1270-1275
Abstract12α-hydroxy-N-demethyl-sauroxine (1), another new Lycopodium alkaloid from the Lycodane group, was isolated from Phlegmariurus saururus (Lam.) B. Øllg. (Lycopodiaceae). Elucidation of the chemical structure and relative stereochemistry were stated by spectroscopic data and chemical correlation. In addition, the inhibitory activity on acetylcholinesterase for 1 was determined as well as for N-methyllycodine (2), a derivative with the same nucleus, previously identified in P. saururus (IC50 = 33.8?±?0.8?μM and 547.5?±?0.5?μM, respectively) and N-demethylsauroxine (3) whose inhibition in the actual conditions was better than the previously informed. 相似文献
998.
Tatiana V. Shishkanova Nina Habanov Michal ezanka Gabriela Broncov Pemysl Fitl Martin Vrata Pavel Matjka 《Electroanalysis》2020,32(4):767-774
We report the electrochemical deposition of a β‐cyclodextrin pyrrole conjugate (Py‐β‐CD) on an electrode surface including i) characterization based on surface‐enhanced Raman scattering and field‐emission scanning electron microscopy; ii) studies of the molecular recognition of enantiomers of phenylalanine methyl ester hydrochlorides (Phe) based on linear sweep voltammetry and a quartz crystal microbalance. The PPy‐β‐CD polymeric layer on a metallic substrate is distinguished by its inhomogeneity, in which both highly ordered β‐CD units and highly disordered polymer chains are observed. The voltammetric recognition results showed that PPy‐β‐CD exhibited a higher sensitivity for d ‐Phe (138±15)×103 than for l ‐Phe (6±1)×103 within the concentration range 0.1–0.75 mM (n=3) despite the differences in the polymer arrangement on the surface. A possible mechanism of molecular recognition of phenylalanine enantiomers is discussed. 相似文献
999.
Păușescu Iulia Todea Anamaria Badea Valentin Peter Francisc Medeleanu Mihai Ledeți Ionuț Vlase Gabriela Vlase Titus 《Journal of Thermal Analysis and Calorimetry》2020,141(3):999-1008
Journal of Thermal Analysis and Calorimetry - Intelligent food packaging systems register and monitor food quality through data carriers, sensors or indicators. Food spoilage often leads to pH... 相似文献
1000.
Luisa Bataglin Avila Elis Regina Correa Barreto Paloma Krolow de Souza Brbara De Zorzi Silva Thamiris Renata Martiny Caroline Costa Moraes Marcilio Machado Morais Vijaya Raghavan Gabriela Silveira da Rosa 《Molecules (Basel, Switzerland)》2020,25(23)
This research investigated the bioactive potential of jaboticaba peel extract (JPE) and proposed an innovative material for food packaging based on carrageenan films incorporated with JPE. The extract was obtained through microwave assisted extraction (MAE) according to central composite rotational design and the optimized conditions showed a combined antimicrobial and antioxidant actions when the extraction process is accomplished at 80 °C and 1 min. The carrageenan film incorporated with JPE was manageable, homogeneous and the presence of JPE into film increased the thickness and improved the light barrier of the film. The results of solubility and mechanical properties did not show significant differences. The benefit of using MAE to improve the recovery of bioactive compounds was demonstrated and the carrageenan film with JPE showed a great strategy to add additives into food packaging. 相似文献