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排序方式: 共有675条查询结果,搜索用时 15 毫秒
1.
Dr. Zhibo Liu Daniel Chao Dr. Ying Li Prof. Dr. Richard Ting Jihyoon Oh Prof. Dr. David M. Perrin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):3924-3928
Organotrifluoroborates solvolyze in water at rates that vary over five orders of magnitude. The negative logarithm of the solvolytic rate constant, pk(B?F), correlates exceptionally well with the pKa of the analogous carboxylic acid (R2=0.984). This unforeseen correlation may be of predictive value for several applications including Suzuki–Miyaura cross‐coupling reactions and the design of 18F‐organotrifluoroborate radioprosthetic groups. 相似文献
2.
Marie-Ange Lespinasse Dr. Kaiyao Wei Justine Perrin Dr. Matthias Winkler Sieme Hamaidia Alexis Leroy Dr. Zuzana Macek Jilkova Dr. Christian Philouze Dr. Patrice N. Marche Dr. Carlo Petosa Dr. Jérôme Govin Dr. Anouk Emadali Dr. Yung-Sing Wong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(64):e202202293
The pharmaceutical industry has a pervasive need for chiral specific molecules with optimal affinity for their biological targets. However, the mass production of such compounds is currently limited by conventional chemical routes, that are costly and have an environmental impact. Here, we propose an easy access to obtain new tetrahydroquinolines, a motif found in many bioactive compounds, that is rapid and cost effective. Starting from simple raw materials, the procedure uses a proline-catalyzed Mannich reaction followed by the addition of BF3 ⋅ OEt2, which generates a highly electrophilic aza-ortho-quinone methide intermediate capable of reacting with different nucleophiles to form the diversely functionalized tetrahydroquinoline. Moreover, this enantioselective one-pot process provides access for the first time to tetrahydroquinolines with a cis-2,3 and trans-3,4 configuration. As proof of concept, we demonstrate that a three-step reaction sequence, from simple and inexpensive starting compounds and catalysts, can generate a BD2-selective BET bromodomain inhibitor with anti-inflammatory effect. 相似文献
3.
Jerome Lozada Wen Xuan Lin Rosana M. Cao-Shen Ruyin Astoria Tai Prof. David M. Perrin 《Angewandte Chemie (International ed. in English)》2023,62(16):e202215371
Tetrafluoroborate (BF4−) has long been used as a spectator counter anion. Herein, we report an unprecedented salt metathesis between a variety of BF4− salts and a series of organoboronic acids yielding the corresponding organotrifluoroborates. We identified conditions for fast and efficient fluoridation (<1 h) with minimal workup. Fundamentally, this work discloses the proclivity of BF4− to exchange fluoride atoms with organoboronates, highlighting the lability of BF4−. 相似文献
4.
Sandy Theysgeur Benoit Cudennec Barbara Deracinois Claire Perrin Isabelle Guiller Anne Lepoudre Christophe Flahaut Rozenn Ravallec 《Molecules (Basel, Switzerland)》2021,26(1)
Like their owners, dogs and cats are more and more affected by overweight and obesity-related problems and interest in functional pet foods is growing sharply. Through numerous studies, fish protein hydrolysates have proved their worth to prevent and manage obesity-related comorbidities like diabetes. In this work, a human in vitro static simulated gastrointestinal digestion model was adapted to the dog which allowed us to demonstrate the promising effects of a tilapia byproduct hydrolysate on the regulation of food intake and glucose metabolism. Promising effects on intestinal hormones secretion and dipeptidyl peptidase IV (DPP-IV) inhibitory activity were evidenced. We identify new bioactive peptides able to stimulate cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1) secretions, and to inhibit the DPP-IV activity after a transport study through a Caco-2 cell monolayer. 相似文献
5.
Levi Evans Yiqui Shen Abigail Bender Leah E. Burnett Musheng Li Justine S. Habibian Tong Zhou Bradley S. Ferguson 《Molecules (Basel, Switzerland)》2021,26(5)
Plant-based foods, like fruits, vegetables, whole grains, legumes, nuts, seeds and other foodstuffs, have been deemed as heart healthy. The chemicals within these plant-based foods, i.e., phytochemicals, are credited with protecting the heart. However, the mechanistic actions of phytochemicals, which prevent clinical endpoints, such as pathological cardiac hypertrophy, are still being elucidated. We sought to characterize the overlapping and divergent mechanisms by which 18 selected phytochemicals prevent phenylephrine- and phorbol 12-myristate 13-acetate-mediated cardiomyocyte enlargement. Of the tested 18 compounds, six attenuated PE- and PMA-mediated enlargement of neonatal rat ventricular myocytes. Cell viability assays showed that apigenin, baicalein, berberine hydrochloride, emodin, luteolin and quercetin dihydrate did not reduce cell size through cytotoxicity. Four of the six phytochemicals, apigenin, baicalein, berberine hydrochloride and emodin, robustly inhibited stress-induced hypertrophy and were analyzed further against intracellular signaling and genome-wide changes in mRNA expression. The four phytochemicals differentially regulated mitogen-activated protein kinases and protein kinase D. RNA-sequencing further showed divergence in gene regulation, while pathway analysis demonstrated overlap in the regulation of inflammatory pathways. Combined, this study provided a comprehensive analysis of cardioprotective phytochemicals. These data highlight two defining observations: (1) that these compounds predominantly target divergent gene pathways within cardiac myocytes and (2) that regulation of overlapping signaling and gene pathways may be of particular importance for the anti-hypertrophic actions of these phytochemicals. Despite these new findings, future works investigating rodent models of heart failure are still needed to understand the roles for these compounds in the heart. 相似文献
6.
Kamel Arraki Perle Totoson Alain Decendit Andy Zedet Justine Maroilley Alain Badoc Cline Demougeot Corine Girard 《Molecules (Basel, Switzerland)》2021,26(6)
Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1–2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C. thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1–7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4–7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model. 相似文献
7.
Y. Hoarau D. Faghani M. Braza R. Perrin D. Anne-Archard D. Ruiz 《Flow, Turbulence and Combustion》2003,71(1-4):119-132
The onset of the secondary instability and the successive steps ofthe 3D transition to turbulence are examined in the flow around a wing of NACA0012 section, constant along the spanwise direction. The wing is placed in a uniform flow upstream, at 20° of incidence and at the Reynolds number of 800. The spanwise length is equal to four chords. The objectives of this study are the identification of the three-dimensional transition mechanism and the development of the early stages of turbulence in the present class of unsteady aerodynamic flows. A detailed processing of the DNS signals carried out by an appropriate conditional sampling allows the identification of the physical mechanisms related to the birth of turbulence and to the non-linear interaction with the 3D coherent structures in the near region. 相似文献
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10.
Pier Alexandre Champagne Yasmine Benhassine Justine Desroches Jean‐Franois Paquin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(50):14055-14059
A Friedel–Crafts benzylation of arenes with benzyl fluorides has been developed. The reaction produces 1,1‐diaryl alkanes in good yield under mild conditions without the need for a transition metal or a strong Lewis acid. A mechanism involving activation of the C F bond through hydrogen bonding is proposed. This mode of activation enables the selective reaction of benzylic C F bonds in the presence of other benzylic leaving groups. 相似文献