Copper-Catalyzed Three-Component Reactions of α-Ketoaldehyde, 1,3-Dicarbonyl Compound, and Organic Boronic Acid in Water: A Route to 1,4-Diketones

Author(s):  
Qi Xia ◽  
Xiang Li ◽  
Xi Fu ◽  
Yaxuan Zhou ◽  
Yanqing Peng ◽  
...  
2018 ◽  
Author(s):  
Suying Xu ◽  
Adam Sedgwick ◽  
Souad Elfecky ◽  
Wenbo Chen ◽  
Ashley Jones ◽  
...  

<p>A boronic acid-based anthracene fluorescent probe was functionalised with an acrylamide unit to incorporate into a hydrogel system for monosaccharide detection<i>. </i>In solution, the fluorescent probe<b> </b>displayed a strong fluorescence turn-on response upon exposure to fructose, and an expected trend in apparent binding constants, as judged by a fluorescence response where D-fructose > D-galactose > D-mannose > D-glucose. The hydrogel incorporating the boronic acid monomer demonstrated the ability to detect monosaccharides by fluorescence with the same overall trend as the monomer in solution with the addition of fructose resulting in a 10-fold enhancement (≤ 0.25 M). <b><u></u></b></p>


2020 ◽  
Author(s):  
Jon Uranga ◽  
Lukas Hasecke ◽  
Jonny Proppe ◽  
Jan Fingerhut ◽  
Ricardo A. Mata

The 20S Proteasome is a macromolecule responsible for the chemical step in the ubiquitin-proteasome system of degrading unnecessary and unused proteins of the cell. It plays a central role both in the rapid growth of cancer cells as well as in viral infection cycles. Herein, we present a computational study of the acid-base equilibria in an active site of the human proteasome, an aspect which is often neglected despite the crucial role protons play in the catalysis. As example substrates, we take the inhibition by epoxy and boronic acid containing warheads. We have combined cluster quantum mechanical calculations, replica exchange molecular dynamics and Bayesian optimization of non-bonded potential terms in the inhibitors. In relation to the latter, we propose an easily scalable approach to the reevaluation of non-bonded potentials making use of QM/MM dynamics information. Our results show that coupled acid-base equilibria need to be considered when modeling the inhibition mechanism. The coupling between a neighboring lysine and the reacting threonine is not affected by the presence of the inhibitor.


2019 ◽  
Author(s):  
Meifeng Wang ◽  
Gan Zhu ◽  
Yiqun Li ◽  
Liuqun Gu

Arylboronic acids were widely used as efficient catalysts in direct amide formation and other organic transformations. Surprisingly, reports on their use as catalysts in carbohydrates synthesis are very rare even though boron acid-diol complexation was extensively investigated in molecular recognition for saccharides and so on. Here we developed an efficient arylboronic acids catalyzed dimerization of glucosamines forming deoxyfructosazine which is important compound in pharmaceutical and food industries, against a commonly held belief that excess amount of phenyl boronic acid (or boric acid) is a must. A catalytic mechanism was also proposed and arylboronic acids instead of their boronates was identified as catalysts.


2018 ◽  
Vol 24 (26) ◽  
pp. 3072-3083 ◽  
Author(s):  
Sowndramalingam Sankaralingam ◽  
Angham Ibrahim ◽  
MD Mizanur Rahman ◽  
Ali H. Eid ◽  
Shankar Munusamy

Background: The incidence and prevalence of diabetes mellitus are increasing globally at alarming rates. Cardiovascular and renal complications are the major cause of morbidity and mortality in patients with diabetes. Methylglyoxal (MG) - a highly reactive dicarbonyl compound – is increased in patients with diabetes and has been implicated to play a detrimental role in the etiology of cardiovascular and renal complications. Derived from glucose, MG binds to arginine and lysine residues in proteins, and the resultant end products serve as surrogate markers of MG generation in vivo. Under normal conditions, MG is detoxified by the enzyme glyoxalase 1 (Glo1), using reduced glutathione as a co-factor. Elevated levels of MG is known to cause endothelial and vascular dysfunction, oxidative stress and atherosclerosis; all of which are risk factors for cardiovascular diseases. Moreover, MG has also been shown to cause pathologic structural alterations and impair kidney function. Conversely, MG scavengers (such as N-acetylcysteine, aminoguanidine or metformin) or Nrf2/Glo1 activators (such as trans-resveratrol / hesperetin) are shown to be useful in preventing MG-induced cardiovascular and renal complications in diabetes. However, clinical evidence supporting the MG lowering properties of these agents are limited and hence, need further investigation. Conclusion: Reducing MG levels directly using scavengers or indirectly via activation of Nrf2/Glo1 may serve as a novel and potent therapeutic strategy to counter the deleterious effects of MG in diabetic complications.


2020 ◽  
Vol 17 ◽  
Author(s):  
Duc Dau Xuan

: The synthesis of the A-B bicyclic ring structure 3 of the natural product Stemocurtisine is described. The synthesis was accomplished in seven synthetic steps from commercially available L-glutamic acid. The key step involved a borono-Mannich reaction between the hemiaminal 6 and trans-β-styryl boronic acid and trans-β-styrylpotassiumtrifluoroborate to prepare the cis diene 4. Attempts to prepare the A-B-C ring compound 2 via intramolecular epoxide ring opening followed by rearangement under different basic conditions were unsuccessful. Only unreactive starting material was recovered.


2021 ◽  
Vol 14 (8) ◽  
pp. 719
Author(s):  
Jiawang Liu ◽  
Nirmal Rajasekaran ◽  
Ahamed Hossain ◽  
Changde Zhang ◽  
Shanchun Guo ◽  
...  

Fulvestrant-3-boronic acid (ZB716), an oral selective estrogen receptor degrader (SERD) under clinical development, has been investigated in ADME studies to characterize its absorption, metabolism, and pharmacokinetics. ZB716 was found to have high plasma protein binding in human and animal plasma, and low intestinal mucosal permeability. ZB716 had high clearance in hepatocytes of all species tested. ZB716 was metabolized primarily by CYP2D6 and CYP3A. In human liver microsomes, ZB716 demonstrated relatively low inhibition of CYP1A2, 2C8, 2C9, 2C19, 2D6, and 3A4 (when testosterone was used as the substrate), and no inhibition of CYP2B6 and 3A4 (when midazolam was used as the substrate). In assays for enzyme activity, ZB716 induced CYP1A2, 2B6, and 3A4 in a concentration-dependent manner. Single-dose and repeated-dose pharmacokinetic studies in rats and dogs showed oral bioavailability, dose-proportional drug exposure, and drug accumulation as measured by maximum concentration and area under the concentration–time curve (AUC).


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