Polymeric membrane sensors with boronic acid functionalized boron dipyrromethene for selective measurement of dopamine

A boronic acid-based anthracene fluorescent probe was functionalised with an acrylamide unit to incorporate into a hydrogel system for monosaccharide detection. In solution, the fluorescent probe 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).

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Theoretical Studies of the Acid-Base Equilibria in a Model Active Site of the Human 20S Proteasome

10.26434/chemrxiv.13388753.v1 ◽

2020 ◽

Author(s):

Jon Uranga ◽

Lukas Hasecke ◽

Jonny Proppe ◽

Jan Fingerhut ◽

Ricardo A. Mata

Keyword(s):

Active Site ◽

Boronic Acid ◽

Computational Study ◽

Ubiquitin Proteasome System ◽

Bayesian Optimization ◽

Inhibition Mechanism ◽

20S Proteasome ◽

Acid Base ◽

Ubiquitin Proteasome ◽

Infection Cycles

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.

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Arylboronic Acids in Self-condensation of Glucosamines Forming Deoxyfructosazine, Catalysts or Reagents?

10.26434/chemrxiv.7528376 ◽

2019 ◽

Author(s):

Meifeng Wang ◽

Gan Zhu ◽

Yiqun Li ◽

Liuqun Gu

Keyword(s):

Molecular Recognition ◽

Boric Acid ◽

Boronic Acid ◽

Catalytic Mechanism ◽

Organic Transformations ◽

Food Industries ◽

Arylboronic Acids ◽

Excess Amount ◽

Phenyl Boronic Acid ◽

Boron Acid

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.

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Faculty Opinions recommendation of Immobilization of peroxidase glycoprotein on gold electrodes modified with mixed epoxy-boronic Acid monolayers.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1010271.149758 ◽

2002 ◽

Author(s):

Vincent Rotello

Keyword(s):

Boronic Acid ◽

Gold Electrodes

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Faculty Opinions recommendation of Discovery of a Cyclic Boronic Acid β-Lactamase Inhibitor (RPX7009) with Utility vs Class A Serine Carbapenemases.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725391898.793505176 ◽

2015 ◽

Author(s):

John Lowe

Keyword(s):

Boronic Acid ◽

Class A ◽

Lactamase Inhibitor

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Preparation and Evaluation of a Gas Formation-based Multiple-Unit Gastro-Retentive Floating Delivery System of Dipyridamole

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2012.5.1.3 ◽

2012 ◽

Vol 5 (1) ◽

pp. 1607-1616

Author(s):

Y. Madhusudan Rao ◽

Katakam V V ◽

S Reddy ◽

J M Somagoni ◽

P K Panakanti ◽

...

Keyword(s):

Drug Release ◽

Delivery System ◽

Polymeric Membrane ◽

Wet Granulation ◽

Physical Parameters ◽

Gastric Residence Time ◽

Gas Formation ◽

Multiple Unit ◽

Model Drug

The aim of this study was to prepare mini tablets to be filled into a capsule that is designed to float on the gastric contents based on gas formation technique. The drug-containing core mini-tablets were prepared by wet granulation method followed by a coating of the core units with seal coating, an effervescent layer and a gas-entrapping polymeric membrane (Eudragit RS30D, RL30D). Dipyridamole, which is predominantly absorbed in the upper part of GI tract and unabsorbed/insoluble at the lower intestine, was used as a model drug. The effect of the preparative parameters like amount of the effervescent agent layered onto the seal coated units, type and coating level of the gas-entrapping polymeric membrane, floating ability and drug release properties of the multiple-unit FDDS were evaluated. The formulations were evaluated for pharmacopoeial quality control tests. Physical parameters were found to be within the acceptable limits. The system using Eudragit® RL30D as a gas-entrapping polymeric membrane exhibited floating properties. The time to float decreased as amount of the effervescent agent increased and coating level of gas-entrapping polymeric membrane decreased. The optimum system exhibited complete floating within 3 minutes and maintained that buoyancy over a period of 8 hours. The drug release was sustained and linear with the square root of time. Increasing the coating level of the gas-entrapping polymeric membrane decreased drug release. Both the rapid-floating and sustained-release properties were achieved in the multiple-unit floating delivery system developed in this study. The in vivo gastric residence time was examined by radiograms and it was found that the units remained in the stomach for about 6 hours. The analysis of the dissolution data after storage at 40°C and 75% RH for 6 months showed no significant change indicating good stability.

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