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141.
Cecilia Rodríguez de Barbarín Sylvain Berns Blanca Njera Perla Elizondo 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(10):o597-o599
Two salts of acyclic Schiff base cationic ligands, namely N,N′‐bis(2‐nitrobenzyl)propane‐1,3‐diammonium dichloride monohydrate, C17H22N4O42+·2Cl−·H2O, (I), and 2‐hydroxy‐N,N′‐bis(2‐nitrobenzyl)propane‐1,3‐diammonium dichloride, C17H22N4O52+·2Cl−, (II), were synthesized as precursors in order to obtain new acyclic and macrocyclic multidentate ligands and complexes. The cation conformations in compounds (I) and (II) are different in the solid state, although the cations are closely related chemically. Similarly, the hydrogen‐bonding networks involving ammonium cations, hydroxyl groups and chloride anions are also different. In the cation of compound (II), the hydroxyl group is disordered over two sets of sites, with occupancies of 0.785 (8) and 0.215 (8). 相似文献
142.
A. H. F. van Vliet Th. de Graauw 《International Journal of Infrared and Millimeter Waves》1981,2(3):465-477
A review is given of different types of quarter wave plates as presently used in the optical and microwave spectral range, with a view to their application in the sub-mm wave-length range. Two types of quarter wave plates have been constructed and results of measurements at 640m are given. 相似文献
143.
1H, 13C, 19F, 31P N.M.R. Characterization of the Alcoholysis Products of Trichlorophosphazene-N-phosphoryldichloride by Trifluoroethanol Since polychlorophosphazenes can be obtained by polycondensation of P2NOCl5 the classical substitution of Cl by CF3CH2O in these polymers was transposed to P2NOCl5. The formation of mono, di, or pentaester depends on the molar ratio of the reactants. By reaction of CF3CH2OH on the pentaester a tetrasubstituted derivative of tetrachlorodiphosphorylimid is obtained. All products are characterized by mass spectroscopy and 1H, 13C, 19F, and 31P n.m.r. 相似文献
144.
The effect of 4,6-O-benzylidene acetals, 4,6-O-phenylboronate esters, and 4,6-O-polystyrylboronate esters on the stereoselectivity of couplings to galacto-, gluco-, and mannopyranosyl thioglycosides, otherwise protected with benzyl ethers, has been investigated by the benzenesulfinyl piperidine/trifluoromethanesulfonic anhydride (BSP), diphenyl sulfoxide/trifluoromethanesulfonic anhydride (Ph(2)SO), and N-iodosuccinimide/trimethylsilyl trifluoromethanesulfonate (NIS/TMSOTf) methods. The BSP and Ph(2)SO methods give comparable results in all three systems whereas the NIS method affords significantly different stereoselectivities in both the gluco and manno, but not the galacto series. The benzylidene acetal and boronate esters influence the stereochemistry in a similar manner in the beta-selective manno series and the alpha-selective galacto series but show significant differences with the glucose donors. The differences between the glucose, galactose, and mannose series reflect the established differences in reactivity and, especially for mannose, those in the anomeric effect and are best interpreted in terms of changes in the relative energetics between the alpha- and beta-covalent triflate intermediates and the various contact ion pairs with which they are necessarily in equilibrium. 相似文献
145.
Gredson Keiff Souza Andr Gallo Luiza Hauser Novicki Heitor Rodrigues Neto Eneida de Paula Anita Jocelyne Marsaioli Luis Fernando Cabea 《Molecules (Basel, Switzerland)》2022,27(13)
The drugs delivery system in the treatment of diseases has advantages such as reduced toxicity, increased availability of the drug, etc. Therefore, studies of the supramolecular interactions between local anesthetics (LAs) butamben (BTB) or ropivacaine (RVC) complexed with 2-hydroxypropyl-β-cyclodextrin (HP-βCD) and carried in Stealth liposomal (SL) are performed. 1H-NMR nuclear magnetic resonance (DOSY and STD) were used as the main tools. The displacements observed in the 1H-NMR presented the complexion between LAs and HP-βCD. The diffusion coefficients of free BTB and RVC were 7.70 × 10−10 m2 s−1 and 4.07 × 10−10 m2 s−1, and in the complex with HP-βCD were 1.90 × 10−10 m2 s−1 and 3.64 × 10−10 m2 s−1, respectively, which indicate a strong interaction between the BTB molecule and HP-βCD (98.3% molar fraction and Ka = 72.279 L/mol). With STD-NMR, the encapsulation of the BTB/HP-βCD and RVC/HP-βCD in SL vesicles was proven. Beyond the saturation transfer to the LAs, there is the magnetization transfer to the hydrogens of HP-βCD. BTB and RVC have already been studied in normal liposome systems; however, little is known of their behavior in SL. 相似文献
146.
Eduardo García-Mingüens Marcos Ferrndiz-Saperas M. de Gracia Retamosa Carmen Njera Miguel Yus Jos M. Sansano 《Molecules (Basel, Switzerland)》2022,27(14)
The enantioselective 1,3-dipolar cycloaddition between imino esters and (Z)-nitroalkenes bearing a masked amino group in the β-position was studied using several chiral ligands and silver salts. The optimized reaction conditions were directly applied to the study of the scope of the reaction. The determination of the absolute configuration was evaluated using NMR experiments and electronic circular dichroism (ECD). The reduction and hydrolysis of both groups was performed to generate in an excellent enantiomeric ratio the corresponding cis-2,3-diaminoprolinate. 相似文献
147.
Thierry Wesley de Albuquerque Aguiar Jos Josenildo Batista Silvio Assis de Oliveira Ferreira Maíra de Vasconcelos Lima Sampaio Dewson Rocha Pereira Magda Rhayanny Assuno Ferreira Luiz Alberto Lira Soares Ana Maria Mendona de Albuquerque Melo Mnica Camelo Pessoa de Azevedo Albuquerque Andr de Lima Aires Hallysson Douglas Andrade de Araújo Luana Cassandra Breitenbach Barroso Coelho 《Molecules (Basel, Switzerland)》2022,27(15)
Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC50 of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC50 of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment. 相似文献
148.
Robson Araújo de Freitas Junior Paloma Kênia de Moraes Berenguel Lossavaro Cndida Aparecida Leite Kassuya Edgar Julian Paredes-Gamero Nelson Carvalho Farias Júnior Maria Inês Lenz Souza Francielli Maria de Souza Silva-Comar Roberto Kenji Nakamura Cuman Denise Brentan Silva Mnica Cristina Toffoli-Kadri Saulo Euclides Silva-Filho 《Molecules (Basel, Switzerland)》2022,27(12)
The aim of this study is to evaluate the phytochemical profile, oral acute toxicity, and the effect of ylang-ylang (Cananga odorata Hook. F. & Thomson) essential oil (YEO) on acute inflammation. YEO was analyzed by gas chromatography/mass spectrometry. For in vitro tests, YEO was assessed using cytotoxicity, neutrophil chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP), and phagocytic activity tests. YEO was orally administered in zymosan-induced peritonitis, carrageenan-induced leukocyte rolling, and adhesion events in the in situ microcirculation model and in carrageenan-induced paw edema models. YEO (2000 mg/kg) was also tested using an acute toxicity test in Swiss mice. YEO showed a predominance of benzyl acetate, linalool, benzyl benzoate, and methyl benzoate. YEO did not present in vitro cytotoxicity. YEO reduced the in vitro neutrophil chemotaxis induced by fMLP and reduced the phagocytic activity. The oral treatment with YEO reduced the leukocyte recruitment and nitric oxide production in the zymosan-induced peritonitis model, reduced rolling and adherent leukocyte number induced by carrageenan in the in situ microcirculation model, and reduced carrageenan-induced edema and mechanical hyperalgesia. YEO did not present signs of toxicity in the acute toxicity test. In conclusion, YEO affected the leukocyte activation, and presented antiedematogenic, anti-hyperalgesic, and anti-inflammatory properties. 相似文献
149.
Rosa I. Ventura-Aguilar Csar Gnzalez-Andrade Mnica Hernndez-Lpez Zormy N. Correa-Pacheco Pervin K. Teksür Margarita de L. Ramos-García Silvia Bautista-Baos 《Molecules (Basel, Switzerland)》2022,27(14)
The fungus Aspergillus flavus causes serious damage to maize grains and its by-products, such as tortilla. Currently, animal and plant derivatives, such as chitosan and propolis, and plant extract residues, respectively, are employed as alternatives of synthetic fungicides. The objective of this research was to evaluate the efficacy of several formulations based on propolis-chitosan-pine resin extract on the in vitro growth of A. flavus, the growth of maize grain plantlets and the quality of stored tortillas at 4 and 28 °C. The most outstanding formulation was that based on 59.7% chitosan + 20% propolis nanoparticles + 20% pine resin extract nanoparticles; since the in vitro conidia germination of A. flavus did not occur, disease incidence on grains was 25–30% and in tortillas, 0% infection was recorded, along with low aflatoxin production (1.0 ppb). The grain germination and seedling growth were markedly reduced by the nanocoating application. The percentage weight loss and color of tortillas were more affected by this coating compared to the control, and the rollability fell within the scale of non-ruptured at 4 °C and partially ruptured at 28 °C. The next step is to evaluate the toxicity of this formulation. 相似文献
150.
In this contribution, we specify the conditions for assuring the validity of the synergy of the distribution of probabilities of occurrence. We also study the subsequent restriction on the maximal extension of the strict concavity region on the parameter space of Sharma–Mittal entropy measures, which has been derived in a previous paper in this journal. The present paper is then a necessary complement to that publication. Some applications of the techniques introduced here are applied to protein domain families (Pfam databases, versions 27.0 and 35.0). The results will show evidence of their usefulness for testing the classification work performed with methods of alignment that are used by expert biologists. 相似文献