Infectious diseases, including bacterial, fungal, and viral, have once again gained urgency in the drug development pipeline after the recent COVID-19 pandemic. Tuberculosis (TB) is an old infectious disease for which eradication has not yet been successful. Novel agents are required to have potential activity against both drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis (Mtb), the causative agent of TB. In this study, we present a series of 2-phenyl-N-(pyridin-2-yl)acetamides in an attempt to investigate their possible antimycobacterial activity, cytotoxicity on the HepG2 liver cancer cell line, and-as complementary testing-their antibacterial and antifungal properties against a panel of clinically important pathogens. This screening resulted in one compound with promising antimycobacterial activity-compound 12, MICMtb H37Ra = 15.625 μg/mL (56.26 μM). Compounds 17, 24, and 26 were further screened for their antiproliferative activity against human epithelial kidney cancer cell line A498, human prostate cancer cell line PC-3, and human glioblastoma cell line U-87MG, where they were found to possess interesting activity worth further exploration in the future.
- MeSH
- acetamidy * chemie farmakologie MeSH
- antifungální látky farmakologie chemie chemická syntéza MeSH
- antituberkulotika farmakologie chemie MeSH
- buňky Hep G2 MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- Mycobacterium tuberculosis * účinky léků MeSH
- nádorové buněčné linie MeSH
- proliferace buněk * účinky léků MeSH
- protinádorové látky farmakologie chemie MeSH
- pyridiny chemie farmakologie MeSH
- SARS-CoV-2 účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Polymicrobial biofilms, the reason for most chronic wound infections, play a significant role in increasing antibiotic resistance. The in vivo effectiveness of the new anti-biofilm therapy is conditioned by the profound evaluation using appropriate in vitro biofilm models. Since nutrient availability is crucial for in vitro biofilm formation, this study is focused on the impact of four selected cultivation media on the properties of methicillin-resistant Staphylococcus aureus and Candida albicans dual-species biofilms. To reflect the wound environment, Tryptic soy broth, RPMI 1640 with and without glucose, and Lubbock medium were supplemented with different amounts of host effector molecules present in human plasma or sheep red blood cells. The study demonstrates that the Lubbock medium provided the most appropriate amount of nutrients regarding the biomass structure and the highest degree of tolerance to selected antimicrobials with the evident contribution of the biofilm matrix. Our results allow the rational employment of nutrition conditions within methicillin-resistant Staphylococcus aureus and Candida albicans dual-species biofilm formation in vitro for preclinical research. Additionally, one of the potential targets of a complex antibiofilm strategy, carbohydrates, was revealed since they are prevailing molecules in the matrices regardless of the cultivation media.
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy * účinky léků růst a vývoj MeSH
- Candida albicans * účinky léků fyziologie MeSH
- kultivační média * farmakologie MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus * účinky léků fyziologie MeSH
- mikrobiální testy citlivosti MeSH
- ovce MeSH
- živiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study presents an exploration of the chemical space around derivatives of 3-benzamidopyrazine-2-carboxamides, previously identified as potent antimycobacterial compounds with predicted binding to mycobacterial prolyl-transfer RNA synthetase. New urea derivatives (Series-1) were generally inactive, probably due to their preference for cis-trans conformation (confirmed by density functional theory calculations and experimentally by nuclear overhauser effect spectroscopy NMR). Series-2 (3-benzamidopyrazine-2-carboxamides with disubstituted benzene ring) demonstrated that substituents larger than fluorine are not tolerated in the ortho position of the benzene ring. This series brought two new compounds (21: R = 2-F, 4-Cl and 22: R = 2-F, 4-Br) with in vitro activity against Mycobacterium tuberculosis H37Rv as well as multidrug-resistant clinical isolates, with minimum inhibitory concentration ranging from 6.25 to 25 μg/mL. The lactone-type derivatives 4H-pyrazino[2,3-d][1,3]oxazin-4-ones (Series-3) were inactive, but solvent stability studies of compound 29 indicated that they might be developed to usable lactone prodrugs of inhibitors of mycobacterial aspartate decarboxylase (PanD).
- MeSH
- aminoacyl-tRNA-synthetasy antagonisté a inhibitory metabolismus MeSH
- antituberkulotika * farmakologie chemie chemická syntéza MeSH
- inhibitory enzymů farmakologie chemie chemická syntéza MeSH
- mikrobiální testy citlivosti * MeSH
- molekulární struktura MeSH
- Mycobacterium tuberculosis * účinky léků enzymologie MeSH
- pyraziny farmakologie chemie chemická syntéza MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
Apart from the SARS-CoV-2 virus, tuberculosis remains the leading cause of death from a single infectious agent according to the World Health Organization. As part of our long-term research, we prepared a series of hybrid compounds combining pyrazinamide, a first-line antitubercular agent, and 4-aminosalicylic acid (PAS), a second-line agent. Compound 11 was found to be the most potent, with a broad spectrum of antimycobacterial activity and selectivity toward mycobacterial strains over other pathogens. It also retained its in vitro activity against multiple-drug-resistant mycobacterial strains. Several structural modifications were attempted to improve the in vitro antimycobacterial activity. The δ-lactone form of compound 11 (11') had more potent in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Compound 11 was advanced for in vivo studies, where it was proved to be nontoxic in Galleria mellonella and zebrafish models, and it reduced the number of colony-forming units in spleens in the murine model of tuberculosis. Biochemical studies showed that compound 11 targets mycobacterial dihydrofolate reductases (DHFR). An in silico docking study combined with molecular dynamics identified a viable binding mode of compound 11 in mycobacterial DHFR. The lactone 11' opens in human plasma to its parent compound 11 (t1/2 = 21.4 min). Compound 11 was metabolized by human liver fraction by slow hydrolysis of the amidic bond (t1/2 = 187 min) to yield PAS and its starting 6-chloropyrazinoic acid. The long t1/2 of compound 11 overcomes the main drawback of PAS (short t1/2 necessitating frequent administration of high doses of PAS).
- MeSH
- antituberkulotika chemie MeSH
- COVID-19 * MeSH
- dánio pruhované MeSH
- kyselina aminosalicylová * farmakologie MeSH
- laktony MeSH
- lidé MeSH
- Mycobacterium tuberculosis * MeSH
- myši MeSH
- pyrazinamid farmakologie MeSH
- SARS-CoV-2 MeSH
- tuberkulóza * farmakoterapie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Background: The development of novel antimicrobial drugs is an essential part of combatting the uprising of antimicrobial resistance. Proper hit-to-lead development is crucially needed. Methods & results: We present a hit-expansion study of N-pyrazinyl- and N-pyridyl-hydroxybenzamides with a comprehensive determination of structure-activity relationships. The antimicrobial screening revealed high selectivity to staphylococci along with antimycobacterial activity with the best value of 6.25 μg/ml against Mycobacterium tuberculosis H37Rv. We proved an inhibition of proteosynthesis and a membrane depolarization of methicillin-resistant Staphylococcus aureus. Conclusion: Our results are a good starting point for further development of new antimicrobial compounds, where the next step would be tuning the potential between relatively nonspecific membrane depolarization effect and specific inhibition of proteosynthesis.
Tuberculosis is the number one killer of infectious diseases caused by a single microbe, namely Mycobacterium tuberculosis (Mtb). The success rate of curing this infection is decreasing due to emerging antimicrobial resistance. Therefore, novel treatments are urgently needed. As an attempt to develop new antituberculars effective against both drugs-sensitive and drug-resistant Mtb, we report the synthesis of a novel series inspired by combining fragments from the first-line agents isoniazid and pyrazinamide (series I) and isoniazid with the second-line agent 4-aminosalicylic acid (series II). We identified compound 10c from series II with selective, potent in vitro antimycobacterial activity against both drug-sensitive and drug-resistant Mtb H37Rv strains with no in vitro or in vivo cytotoxicity. In the murine model of tuberculosis, compound 10c caused a statistically significant decrease in colony-forming units (CFU) in spleen. Despite having a 4-aminosalicylic acid fragment in its structure, biochemical studies showed that compound 10c does not directly affect the folate pathway but rather methionine metabolism. In silico simulations indicated the possibility of binding to mycobacterial methionine-tRNA synthetase. Metabolic study in human liver microsomes revealed that compound 10c does not have any known toxic metabolites and has a half-life of 630 min, overcoming the main drawbacks of isoniazid (toxic metabolites) and 4-aminosalicylic acid (short half-life).
- MeSH
- antituberkulotika chemie MeSH
- isoniazid farmakologie MeSH
- kyselina aminosalicylová * farmakologie MeSH
- lidé MeSH
- methionin MeSH
- mikrobiální testy citlivosti MeSH
- Mycobacterium tuberculosis * MeSH
- myši MeSH
- tuberkulóza * farmakoterapie mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
In this study, we have focused on a multiparametric microbiological analysis of the antistaphylococcal action of the iodinated imine BH77, designed as an analogue of rafoxanide. Its antibacterial activity against five reference strains and eight clinical isolates of Gram-positive cocci of the genera Staphylococcus and Enterococcus was evaluated. The most clinically significant multidrug-resistant strains, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and vancomycin-resistant Enterococcus faecium, were also included. The bactericidal and bacteriostatic actions, the dynamics leading to a loss of bacterial viability, antibiofilm activity, BH77 activity in combination with selected conventional antibiotics, the mechanism of action, in vitro cytotoxicity, and in vivo toxicity in an alternative animal model, Galleria mellonella, were analyzed. The antistaphylococcal activity (MIC) ranged from 15.625 to 62.5 μM, and the antienterococcal activity ranged from 62.5 to 125 μM. Its bactericidal action; promising antibiofilm activity; interference with nucleic acid, protein, and peptidoglycan synthesis pathways; and nontoxicity/low toxicity in vitro and in vivo in the Galleria mellonella model were found to be activity attributes of this newly synthesized compound. In conclusion, BH77 could be rightfully minimally considered at least as the structural pattern for future adjuvants for selected antibiotic drugs. IMPORTANCE Antibiotic resistance is among the largest threats to global health, with a potentially serious socioeconomic impact. One of the strategies to deal with the predicted catastrophic future scenarios associated with the rapid emergence of resistant infectious agents lies in the discovery and research of new anti-infectives. In our study, we have introduced a rafoxanide analogue, a newly synthesized and described polyhalogenated 3,5-diiodosalicylaldehyde-based imine, that effectively acts against Gram-positive cocci of the genera Staphylococcus and Enterococcus. The inclusion of an extensive and comprehensive analysis for providing a detailed description of candidate compound-microbe interactions allows the valorization of the beneficial attributes linked to anti-infective action conclusively. In addition, this study can help with making rational decisions about the possible involvement of this molecule in advanced studies or may merit the support of studies focused on related or derived chemical structures to discover more effective new anti-infective drug candidates.
- MeSH
- antibakteriální látky farmakologie chemie MeSH
- antiinfekční látky * farmakologie MeSH
- Enterococcus MeSH
- methicilin rezistentní Staphylococcus aureus * MeSH
- mikrobiální testy citlivosti MeSH
- rafoxanid farmakologie MeSH
- Staphylococcus aureus MeSH
- Staphylococcus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Background: Increasing rates of acquired resistance have justified the critical need for novel antimicrobial drugs. One viable concept is the modification of known drugs. Methods & results: 21 mafenide-based compounds were prepared via condensation reactions and screened for antimicrobial efficacy, which demonstrated promising activity against both Gram-positive and Gram-negative pathogens, pathogenic fungi and mycobacterial strains (minimum inhibitory concentrations from 3.91 μM). Importantly, they retained activity against a panel of superbugs (methicillin- and vancomycin-resistant staphylococci, enterococci, multidrug-resistant Mycobacterium tuberculosis) without any cross-resistance. Unlike mafenide, most of its imines were bactericidal. Toxicity to HepG2 cells was also investigated. Conclusion: Schiff bases were significantly more active than the parent drug, with iodinated salicylidene and 5-nitrofuran/thiophene-methylidene scaffolds being preferred in identifying the most promising drug candidates.
Tuberculosis remains a serious killer among infectious diseases due to its incidence, mortality, and occurrence of resistant mycobacterial strains. The challenge to discover new antimycobacterial agents forced us to prepare a series of N-(1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborol-6-yl)(hetero)aryl-2-carboxamides 1-19 via the acylation of 6-aminobenzo[c][1,2]oxaborol-1(3H)-ol with various activated (hetero)arylcarboxylic acids. These novel compounds have been tested in vitro against a panel of clinically important fungi and bacteria, including mycobacteria. Some of the compounds inhibited the growth of mycobacteria in the range of micromolar concentrations and retained this activity also against multidrug-resistant clinical isolates. Half the maximal inhibitory concentrations against the HepG2 cell line indicated an acceptable toxicological profile. No growth inhibition of other bacteria and fungi demonstrated selectivity of the compounds against mycobacteria. The structure-activity relationships have been derived and supported with a molecular docking study, which confirmed a selectivity toward the potential target leucyl-tRNA synthetase without an impact on the human enzyme. The presented compounds can become important materials in antimycobacterial research.
- MeSH
- amidy chemie farmakologie MeSH
- aminoacyl-tRNA-synthetasy * MeSH
- antibakteriální látky farmakologie MeSH
- antiinfekční látky * farmakologie MeSH
- antituberkulotika farmakologie MeSH
- houby MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- Mycobacterium tuberculosis * MeSH
- simulace molekulového dockingu MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
