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121.
122.
Aline de Souza Ramos Joyce Benzaquem Ribeiro Leonardo Vazquez Selma Gomes Ferreira Leite Francisco Radler de Aquino Neto 《Tetrahedron letters》2009,50(52):7362-6129
The enantioselective reduction of ethyl benzoylacetate (EBA) into ethyl (S)-3-hydroxy-3-phenylpropanoate (S-HPPE) by nine yeast strains and three filamentous fungi strains is described. The conversion obtained was in the range 0-89% and the enantiomeric excess was 100% in many cases. Conversion levels were higher when the reduction was performed with microorganisms immobilized in calcium alginate and enantioselectivity remained excellent. Some reaction’s conditions of bioreduction by immobilized cells of Rhodotorula rubra were studied using a 25-2 fractional factorial design. 相似文献
123.
Assist. Prof. Dr. Sumbal Saba Caio R. Dos Santos Bruno R. Zavarise Aline A. S. Naujorks Marcelo S. Franco Alex R. Schneider Marcos R. Scheide Dr. Ricardo F. Affeldt Assoc. Prof. Dr. Jamal Rafique Prof. Dr. Antonio L. Braga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(20):4461-4466
Herein, a greener approach to the eosin Y-Na2 catalyzed, C(sp2)−H bond azo coupling of imidazoheteroarene with aryl diazonium salts is described, under acid free conditions. This direct photoredox process resulted in the corresponding azo products in good to excellent yields. Besides, this new approach could also be applicable to anilines, which is a poorly reactive substrate by other methods. The main features of this reaction are that it provides high yields and is gram-scalable and applicable to biologically relevant imidazoheteroarenes and -anilines. 相似文献
124.
Rodrigo Brito Santos Railmara Pereira da Silva Felipe Akihiro Melo Otsuka Danielle de Jesus Trindade Aline Costa Santos Humberto Reis Matos 《Biomedical chromatography : BMC》2019,33(4)
Hexokinases play a critical role in the cellular uptake and utilization of glucose. As such, they are of fundamental importance to all cells. By catalyzing glucose to produce glucose‐6‐phosphate, hexokinases control the first irreversible step of glucose metabolism and initiate all major pathways of glucose consumption. Our objective was to develop and validate highly sensitive and selective high‐performance liquid chromatography with photodiode array detector (HPLC‐PDA) assays allowing the determination of adenosine diphosphate, which was used for the determination of hexokinase activity. Samples were analyzed by HPLC‐PDA using a C18 analytical column (250 × 4.6 mm) for chromatographic separation. Optimal detection was achieved based on isocratic elution with a mobile phase consisting of a mixture of sodium phosphate monobasic buffer and methanol. This method met all of the requirements of specificity, sensitivity, linearity, precision, accuracy and stability generally accepted in bioanalytical chemistry and was successfully applied to a study of hexokinase activity in an alloxan‐induced diabetic rat model. Determination of hexokinase activity will permit characterization of cellular metabolic state in many diseases, such as cancer and diabetes. 相似文献
125.
126.
Dr. Thierry Achard Julien Egly Michel Sigrist Dr. Aline Maisse-François Dr. Stéphane Bellemin-Laponnaz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(58):13271-13274
A dehydrogenation of primary amine to give the corresponding nitrile under oxidant- and base-free conditions catalysed by simple [Ru(p-cym)Cl2]2 with no extra ligand is reported. The system is highly selective for alkyl amines, whereas benzylamine derivatives gave the nitrile product together with the imine in a ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity. 相似文献
127.
Gisele Luiza Pavan Igor Tadeu Lazzarotto Bresolin Aline Ferreira Velho Muzio Daniele Celestino Cunha Sonia Maria Alves Bueno 《Biomedical chromatography : BMC》2019,33(1)
The behavior of human immunoglobulin G (IgG) and antigen‐binding fragment (Fab fragment) adsorption onto phospho‐l ‐tyrosine immobilized on agarose (P‐Tyr‐agarose) was evaluated by pseudoaffinity chromatography. The effects of buffer systems MES, MOPS, Bis–Tris, Tris–HCl and sodium phosphate (NaP) and pH on IgG adsorption were studied and high purity values were obtained (96%, based on ELISA analysis of albumin, transferrin and immunoglobulins A, G and M) when IgG was purified from human plasma diluted in 10 mmol L?1 NaP buffer at pH 6.0. The capture of IgG by the P‐Tyr‐agarose was also promising, since 91% of the IgG was adsorbed when plasma was diluted in 25 mmol L?1 MES buffer at pH 5.5, recommending its use for IgG depletion from human plasma under this condition. The experimental data on IgG adsorption kinetics were in agreement with the pseudo‐second‐order model. The adsorption isotherm data were well described by the Langmuir–Freundlich model with the value of parameter n being <1 (0.72), indicating negative cooperativity. Selectivity was achieved on P‐Tyr‐agarose from digested human IgG in HEPES 25 mmol L?1 buffer at pH 7.0 where Fab fragments were obtained in eluted fractions without Fc fragments (but with uncleaved IgG) with 86.2% recovery. 相似文献
128.
HPLC‐DAD for the determination of three different classes of antifungals: method characterization,statistical approach,and application to a permeation study 下载免费PDF全文
Diogo Miron Alini Lange Aline R. Zimmer Paulo Mayorga Elfrides E. S. Schapoval 《Biomedical chromatography : BMC》2014,28(12):1728-1737
This study describes and characterizes methods for high‐performance liquid chromatography diode array detection (HPLC‐DAD) analysis of formulations containing molecules with antifungal activity of three different classes: terbinafine and butenafine (allylamines), miconazole and fluconazole (azoles), and geraniol, neral and geranial (monoterpenes). All methods used the same chromatographic column (RP18), enabling the analysis to be performed in a single batch. The specificity was extensively discussed through the establishment of purity peak methods. The analytical parameters (linearity, precision and accuracy) were calculated and discussed in detail using specific statistical approaches. All substances showed satisfactory results for chromatographic and analytical parameters. Limits of 1.3% to mean repeatability and 2.0% for intermediate precision are suggested as acceptance criteria in validation of methods by HPLC‐DAD, in situations where there is no extensive pretreatment of the samples. The methods proved to be robust and significant factors were discussed regarding their influence on chromatographic parameters (retention time, resolution, tailing factor and column efficiency). Finally, the application of the developed methods was demonstrated by the results of a permeation study of the antifungal agents through bovine hoof membranes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
129.
Aline de Souza Ramos Raquel de Oliveira Lopes Rodrigo Octavio Mendonça Alves de Souza 《合成通讯》2013,43(12):1611-1618
The β-ketoester tert-butyl acetoacetate was enantioselectively reduced to tert-butyl (S)-3-hydroxybutanoate by seven microorganism strains. The best result using free cells was obtained with the yeast R. rubra, which furnished 97.6% ee and higher than 99% of conversion within 24 h. After immobilization in calcium alginate spheres, R. rubra furnished 96% ee and higher than 99% ee within 24 h, even if substrate concentration was 58 mM. Immobilized cells were reused three times without loss of enantioselectivity. 相似文献
130.
Aline Staub Serge Rudaz Jean-Luc Veuthey Julie Schappler 《Journal of chromatography. A》2010,1217(51):8041-8047
This paper describes an efficient CE-UV-ESI-TOF/MS method for the determination and quantitation of intact insulin (INS) in a pharmaceutical formulation. The CE conditions were optimized to avoid the adsorption of proteins onto the capillary wall. Particular attention was paid regarding the choice of the internal standard (IS). A strategy based on multiple injections was selected and the methodology was validated according to international guidelines. The optimized method was applied with success to the analysis of INS formulations obtained from regular and parallel markets. 相似文献