5-Trifluoromethyl-2-formylphenylboronic Acid.

Agnieszka Adamczyk-Woźniak,Andrzej Sporzyński,Ewa Brzezińska,Jacek Lipok,Ewa Kaczorowska,Izabela D. Madura,Dorota Wieczorek,Jan T. Gozdalik

doi:10.3390/molecules25040799

Agnieszka Adamczyk-Woźniak, Andrzej Sporzyński + Show 6 more

Open Access

https://doi.org/10.3390/molecules25040799

Copy DOI

Abstract

2-Formylphenylboronic acids display many interesting features, not only from synthetic but also from an application as well as structural points of view. 5-Trifluoromethyl-2-formyl phenylboronic acid has been synthesized and characterized in terms of its structure and properties. The presence of an electron-withdrawing substituent results in a considerable rise in the acidity in comparison with its analogues. In some solutions, the title compound isomerizes with formation of the corresponding 3-hydroxybenzoxaborole. Taking into account the probable mechanism of antifungal action of benzoxaboroles, which blocks the cytoplasmic leucyl-tRNA synthetase (LeuRS) of the microorganism, docking studies with the active site of the enzymes have been carried out. It showed possible binding of the cyclic isomer into the binding pocket of Candida albicans LeuRS, similar to that of the recently approved benzoxaborole antifungal drug (AN2690, Tavaborole, Kerydin). In case of Escherichia coli LeuRS, the opened isomer displays a much higher inhibition constant in comparison with the cyclic one. The antimicrobial activity of the title compound was also investigated in vitro, showing moderate action against Candida albicans. The compound reveals higher activity against Aspergillus niger as well as bacteria such as Escherichia coli and Bacillus cereus. In case of Bacillus cereus, the determined Minimum Inhibitory Concentration (MIC) value is lower than that of AN2690 (Tavaborole). The results confirm potential of 2-formylphenylboronic acids as antibacterial agents and give a hint of their possible mechanism of action.

Highlights

Boronic acids and especially arylboronic acids are of significant importance in chemistry
The title compound synthesized from the corresponding bromobenzaldehyde in a two-step
The title compound was synthesized from the corresponding bromobenzaldehyde in a two-step reaction according to a typical procedure

Summary

Introduction

Boronic acids and especially arylboronic acids are of significant importance in chemistry. There are many examples of application of arylboronic acids, among others: building blocks in organic chemistry, sensors and receptors, polymers, active ingredients of drugs, functionalization of nanoparticles, boron neutron capture therapy (BNCT) and positron emission tomography (PET) [1,2,3,4,5]. The 2-formylphenylboronic acids are very interesting from the structural point of view, since many interactions of the formyl group with the neighboring boronic unit are possible. Those interactions have been investigated by X-ray in the solid state [7]. One of Molecules 2020, 25, 799; doi:10.3390/molecules25040799 www.mdpi.com/journal/molecules

Methods

Results

Conclusion