Boronic Acids of Pharmaceutical Importance Affect the Growth and Photosynthetic Apparatus of Cyanobacteria in a Dose-Dependent Manner.

Emilia Niemczyk,Jerzy Pogrzeba,Jacek Lipok,Agnieszka Adamczyk-Woźniak

doi:10.3390/toxins12120793

Emilia Niemczyk, Jerzy Pogrzeba + Show 2 more

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https://doi.org/10.3390/toxins12120793

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Journal: Toxins	Publication Date: Dec 13, 2020
Citations: 1	License type: CC BY 4.0

Affiliation: Opole University, Warsaw University of Technology

Abstract

The dynamic increase in the commercial application of antimicrobial derivatives of boronic acids, and potential impact of their presence in aquatic systems, supports the necessity to study the toxicity of these substances towards microorganisms of crucial meaning in the environment. One example of the mentioned derivatives is tavaborole (5-fluoro-substituted benzoxaborole), a pharmaceutical agent with antifungal activity. Cyanobacteria were used as model organisms, which are photoautotrophic prokaryotes, as representative aquatic bacteria and photoautotrophs associated with the plant kingdom. To the best of our knowledge, we investigated this issue for the first time. In order to recognize the under-stress response of those microorganisms, the concentration of photopigments—a key factor in the activity of photosynthetic apparatus—was measured spectrophotometrically. We found that the 3-piperazine bis(benzoxaborole) significantly suppressed the growth of halophilic and freshwater cyanobacteria, at a concentration 3.0 mM and 0.3 mM, respectively. Our results also showed that the tested substances at micromolar concentrations stimulated the growth of cyanobacteria, particularly in the freshwater strain Chroococcidiopsis thermalis. The tested substances acted with various strengths, depending on their structure and concentration; nevertheless, they had a greater influence on the synthesis of phycobiliproteins (e.g., lowered their concentration) than on the formation of chlorophyll and carotenoids.

Highlights

Boron does not occur as a pure element on Earth, but it is contained in detectable amounts in mineral connections, for example, 5 mg per 1 kg in basalts, 100 mg per 1 kg in shellfish shells, and 4.5 mg dissolved in 1 L of ocean water
Due to earlier proven significant differences in the sensitivity of halophilic and freshwater cyanobacteria to xenobiotics, the concentration ranges of aryl boronic acids varied by one order of magnitude
Cyanobacteria are considered the most common photoautotrophic organisms in biospheres, which may act as very good model organisms in toxicity studies due to their belonging to prokaryotes

Summary

Introduction

Boron does not occur as a pure element on Earth, but it is contained in detectable amounts in mineral connections (like oxides), for example, 5 mg per 1 kg in basalts, 100 mg per 1 kg in shellfish shells, and 4.5 mg dissolved in 1 L of ocean water. B(OH)4 − , its concertation in freshwater varies around 0.1–0.5 mg/L [1,2,3,4] Toxins 2020, 12, 793 was identified in the structure of the organic compound boromycin, which is a macrolide antibiotic produced by cyanobacteria belonging to the Nostoc genus; it is an effective agent against most. Research on the role of organic derivatives of boronic acid in the metabolism. Because ofwas theidentified high toxicity to microorganisms and lackboromycin, of negative effects on mammals, boronic acid produced by cyanobacteria belonging the Nostoc genus; it isas an effective agent against most compounds are synthesized and testedtofor possible use active constituents of Gramantifungal and positive bacteria [5]. Research on the role of organic derivatives of boronic acid in the metabolism of antibacterial drugs. The first results indicated that some compounds from this group, such as tavaborole microorganisms showed that, depending on their structure, there can be different impacts on bacteria (5-fluoro-substituted benzoxaborole)

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