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91.
Jos Renato Guimares Letícia Passos Miranda Roberto Fernandez-Lafuente Paulo Waldir Tardioli 《Molecules (Basel, Switzerland)》2021,26(1)
The performance of the previously optimized magnetic cross-linked enzyme aggregate of Eversa (Eversa-mCLEA) in the enzymatic synthesis of biolubricants by transesterification of waste cooking oil (WCO) with different alcohols has been evaluated. Eversa-mCLEA showed good activities using these alcohols, reaching a transesterification activity with isoamyl alcohol around 10-fold higher than with methanol. Yields of isoamyl fatty acid ester synthesis were similar using WCO or refined oil, confirming that this biocatalyst could be utilized to transform this residue into a valuable product. The effects of WCO/isoamyl alcohol molar ratio and enzyme load on the synthesis of biolubricant were also investigated. A maximum yield of around 90 wt.% was reached after 72 h of reaction using an enzyme load of 12 esterification units/g oil and a WCO/alcohol molar ratio of 1:6 in a solvent-free system. At the same conditions, the liquid Eversa yielded a maximum ester yield of only 34%. This study demonstrated the great changes in the enzyme properties that can be derived from a proper immobilization system. Moreover, it also shows the potential of WCO as a feedstock for the production of isoamyl fatty acid esters, which are potential candidates as biolubricants. 相似文献
92.
Duarte Valdyster Shirley Santos Rodrigues Aldimar Machado de Andrade-Filho Tarciso Silva Souza Divanizia do Nascimento de Novais Erico Raimundo Pereira Novais Andréa de Lima Ferreira de Oliveira Glaura Caroena Azevedo 《Structural chemistry》2021,32(4):1589-1595
Structural Chemistry - We investigatethe electronic and structural properties of two new amorphous materials, Bi6Ca2O28B12 and Bi6Ca2 O28B11:Tm, using density functional theory with a short-range... 相似文献
93.
de Souza EA Neves CA de Oliveira Campos LA Zanuncio JC Serrão JE 《Micron (Oxford, England : 1993)》2007,38(5):471-477
The effect of mating delay on the ovary structure of virgin queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae) was investigated. Virgin queens 15, 20, 25 and 30 days old were dissected to analyze their degree of ovary degeneration. To verify whether the degeneration would cause permanent sterility, virgin queens of the same ages (15, 20, 25 and 30 days) were mated and accompanied for at least 14 days to verify whether there was physogastry and then dissected. The ovaries were analyzed by histology, histochemical tests and TUNEL to verify programmed cell death. The results showed that mating delay interrupted oogenesis preventing vitellogenesis. Mating delay results in ovary degeneration which increased with queen age. However, even when there was ovariole degeneration, 25-day-old virgin queens after mating presented normal ovariole activation. 相似文献
94.
Godoi C. M. Santos M. C. L. Silva A. J. Tagomori T. L. Ramos A. S. de Souza R. F. B. Neto A. Oliveira 《Research on Chemical Intermediates》2021,47(2):743-757
Research on Chemical Intermediates - PdxCuy/C catalysts combinations were employed to CH4 partial oxidation in mild condition using a solid electrolyte reactor—alkaline fuel cell type. The... 相似文献
95.
96.
Weixun Wang Bernard K. Choi Wenyu Li Zhege Lao Anita Y. H. Lee Sandra C. Souza Nathan A. Yates Timothy Kowalski Alessandro Pocai Lucinda H. Cohen 《Journal of the American Society for Mass Spectrometry》2014,25(4):614-625
Stromal cell-derived factor 1α (SDF-1α) or CXCL12 is a small pro-inflammatory chemoattractant cytokine and a substrate of dipeptidyl peptidase IV (DPP-IV). Proteolytic cleavage by DPP-IV inactivates SDF-1α and attenuates its interaction with CXCR4, its cell surface receptor. To enable investigation of suppression of such inactivation with pharmacologic inhibition of DPP-IV, we developed quantitative mass spectrometric methods that differentiate intact SDF-1α from its inactive form. Using top-down strategy in quantification, we demonstrated the unique advantage of keeping SDF-1α’s two disulfide bridges intact in the analysis. To achieve the optimal sensitivity required for quantification of intact and truncated SDF-1α at endogenous levels in blood, we coupled nano-flow tandem mass spectrometry with antibody-based affinity enrichment. The assay has a quantitative range of 20 pmol/L to 20 nmol/L in human plasma as well as in rhesus monkey plasma. With only slight modification, the same assay can be used to quantify SDF-1α in mice. Using two in vivo animal studies as examples, we demonstrated that it was critical to differentiate intact SDF-1α from its truncated form in the analysis of biomarkers for pharmacologic inhibition of DPP-IV activity. These novel methods enable translational research on suppression of SDF-1 inactivation with DPP-IV inhibition and can be applied to relevant clinical samples in the future to yield new insights on change of SDF-1α levels in disease settings and in response to therapeutic interventions. Figure
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97.
Dr. Alexander Sachse Caroline Wuttke Dr. Elízio Lissner Dr. Michèle Oberson de Souza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):14996-14999
Hierarchically porous ZSM‐5 was achieved by using a simple bottom‐up strategy combining zeolite seeds with imidazolium‐based ionic liquids. The bimodal ZSM‐5 with hexagonal arranged mesopores (3 nm) shows important activity in the acid catalysis of bulky compounds relative to conventional ZSM‐5. 相似文献
98.
Marcileia Zanatta Dr. Anne‐Lise Girard Nathalia M. Simon Prof. Gunter Ebeling Prof. Hubert K. Stassen Prof. Paolo R. Livotto Prof. Francisco P. dos Santos Prof. Jairton Dupont 《Angewandte Chemie (International ed. in English)》2014,53(47):12817-12821
1‐n‐Butyl‐2,3‐dimethylimidazolium (BMMI) ionic liquids (ILs) associated with different anions undergo H/D exchange preferentially at 2‐Me group of the imidazolium in deuterated solvents. This process is mainly related to the existence of ion pairs rather than the anion basicity. The H/D exchange occurs in solvents (CDCl3 and MeCN for instance) in which intimate contact ion pairs are present and the anion possesses a labile H in its structure, such as hydrogen carbonate and prolinate. In D2O, separated ion pairs are formed and the H/D exchange does not occur. A plausible catalytic cycle is that the IL behaves as a neutral base in the course of all H/D exchange processes. NMR experiments, density functional calculations, and molecular dynamics simulations corroborate these hypotheses. 相似文献
99.
TEAD–YAP Interaction Inhibitors and MDM2 Binders from DNA-Encoded Indole-Focused Ugi Peptidomimetics
Verena B. K. Kunig Dr. Marco Potowski Dr. Mohammad Akbarzadeh Dr. Mateja Klika Škopić Denise dos Santos Smith Lukas Arendt Ina Dormuth Dr. Hélène Adihou Blaž Andlovic Dr. Hacer Karatas Shabnam Shaabani Tryfon Zarganes-Tzitzikas Prof. Dr. Constantinos G. Neochoritis Ran Zhang Prof. Dr. Matthew Groves Dr. Stéphanie M. Guéret Dr. Christian Ottmann Prof. Dr. Jörg Rahnenführer Prof. Dr. Roland Fried Prof. Dr. Alexander Dömling Dr. Andreas Brunschweiger 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20518-20522
DNA-encoded combinatorial synthesis provides efficient and dense coverage of chemical space around privileged molecular structures. The indole side chain of tryptophan plays a prominent role in key, or “hot spot”, regions of protein–protein interactions. A DNA-encoded combinatorial peptoid library was designed based on the Ugi four-component reaction by employing tryptophan-mimetic indole side chains to probe the surface of target proteins. Several peptoids were synthesized on a chemically stable hexathymidine adapter oligonucleotide “hexT”, encoded by DNA sequences, and substituted by azide-alkyne cycloaddition to yield a library of 8112 molecules. Selection experiments for the tumor-relevant proteins MDM2 and TEAD4 yielded MDM2 binders and a novel class of TEAD-YAP interaction inhibitors that perturbed the expression of a gene under the control of these Hippo pathway effectors. 相似文献
100.
Baburajan A. Sudheendran V. Gaikwad R. H. Ravi P. M. Nayak Rashmi S. D’Souza Shiny Renita Karunakara N. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(1):441-443
Journal of Radioanalytical and Nuclear Chemistry - The original publication of the article contains errors in the text and Tables 3, 4 and 5. The corrected text and tables are provided in... 相似文献