Preparation and in vitro screening of quartenary inhibitors of acetylcholinesterase

Příprava a in vitro screening kvarterních inhibitorů acetylcholinesterasy Abstrakt Reversibilní inhibitory acetylcholinesterasy (AChE) našly široké uplatnění v lidské farmakoterapii. Jednou z oblastí jejich využití je profylaxe otravy organofosforovými sloučeninami (OF). K tomuto účelu jsou v současné době používány karbamátové inhibitory (např. pyridostigmin-chlorid). Karbamátový inhibitor se naváže na aktivní místo enzymu, a tím ho ochrání před ireversibilní inhibicí způsobenou OF. Vzhledem k mnoha nežádoucím účinkům těchto látek je snaha nalézt mezi inhibitory AChE vhodnější alternativu. V rámci této diplomové práce bylo připraveno 19 potenciálních inhibitorů AChE a in vitro byla stanovena jejich účinnost vůči AChE a butyrylcholinesterase. Výsledky byly porovnány se selektivními standardními inhibitory cholinesteras BW284c51 a ethopropazinem. Žádná z připravených sloučenin nevykázala vyšší účinnost nebo selektivitu než použité standardy. Na základě získaných dat byly stanoveny vztahy mezi strukturou a účinkem připravených sloučenin.Preparation and in vitro screening of quarternary inhibitors of acetylcholinesterase Abstract Reversible acetylcholinesterase (AChE) inhibitors are extensively used in human medicine. Among other applications they are used as a pre-exposure treatment for the prevention of organophosphorus poisoning. For this purpose carbamate inhibitors are recently used (e.g. pyridostigmine chloride). Carbamates reversibly block AChE active site and thus protect AChE against irreversible inhibition by organophosphorus compounds. However, these drugs have many undesirable side-effects and thus there are efforts to find a more suitable alternative among reversible AChE inhibitors. In this diploma thesis, 19 potential AChE inhibitors were prepared. Their ability to inhibit AChE and butyrylcholinesterase was evaluated in vitro and compared to selective standard cholinesterase inhibitors BW284c51 and ethopropazine. None of the prepared compounds was superior to used standards in inhibitory ability or selectivity. The structure activity relationship of the novel compounds was determinated from the obtained data.Department of Pharmaceutical Chemistry and Drug ControlKatedra farmaceutické chemie a kontroly léčivFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov

New dual ATP-competitive inhibitors of bacterial DNA gyrase and topoisomerase IV active against ESKAPE pathogens

The rise in multidrug-resistant bacteria defines the need for identification of new antibacterial agents that are less prone to resistance acquisition. Compounds that simultaneously inhibit multiple bacterial targets are more likely to suppress the evolution of target-based resistance than monotargeting compounds. The structurally similar ATP binding sites of DNA gyrase and topoisomerase. offer an opportunity to accomplish this goal. Here we present the design and structure-activity relationship analysis of balanced, low nanomolar inhibitors of bacterial DNA gyrase and topoisomerase IV that show potent antibacterial activities against the ESKAPE pathogens. For inhibitor 31c, a crystal structure in complex with Staphylococcus aureus DNA gyrase B was obtained that confirms the mode of action of these compounds. The best inhibitor, 31h, does not show any in vitro cytotoxicity and has excellent potency against Gram-positive (MICs: range, 0.0078-0.0625 mg/mL) and Gram-negative pathogens (MICs: range, 1-2 mg/mL). Furthermore, 31h inhibits GyrB mutants that can develop resistance to other drugs. Based on these data, we expect that structural derivatives of 31h will represent a step toward clinically efficacious multitargeting antimicrobials that are not impacted by existing antimicrobial resistance. (C) 2021 Elsevier Masson SAS. All rights reserved.Peer reviewe

Preparation and evaluation of potential drugs inhibiting mitochondrial enzymes

Preparation and evaluation of potential drugs inhibiting mitochondrial enzymes Summary in English Alzheimer's disease (AD) is the most common cause of senile dementia worldwide. Despite being subject to intensive research, the pathogenic mechanisms of AD are still not fully understood and consequently an effective treatment is yet to be developed. Although the aetiology of AD is still unknown, a build-up of amyloid-beta peptide (Aβ) is considered to play an important role in disease progression. The original amyloid cascade hypothesis proposed that insoluble extracellular plaques were responsible for the majority of Aβ toxicity. This hypothesis has since been refined, as recent data indicates that soluble intracellular oligomers are now responsible for the majority of Aβ induced toxic effects. The mitochondrial dysfunction also plays an important role in the pathophysiology of AD. Aβ was detected inside mitochondria and several mitochondrial proteins were found to interact directly with Aβ. Such interactions can affect a protein's function and cause damage to the mitochondria, which finally results in progression of AD. The background for the experimental part of this dissertation thesis was literature review summarizing current knowledge on mitochondrial proteins directly interacting with Aβ in order to..

Preparation and in vitro screening of quartenary inhibitors of acetylcholinesterase

Preparation and in vitro screening of quarternary inhibitors of acetylcholinesterase Abstract Reversible acetylcholinesterase (AChE) inhibitors are extensively used in human medicine. Among other applications they are used as a pre-exposure treatment for the prevention of organophosphorus poisoning. For this purpose carbamate inhibitors are recently used (e.g. pyridostigmine chloride). Carbamates reversibly block AChE active site and thus protect AChE against irreversible inhibition by organophosphorus compounds. However, these drugs have many undesirable side-effects and thus there are efforts to find a more suitable alternative among reversible AChE inhibitors. In this diploma thesis, 19 potential AChE inhibitors were prepared. Their ability to inhibit AChE and butyrylcholinesterase was evaluated in vitro and compared to selective standard cholinesterase inhibitors BW284c51 and ethopropazine. None of the prepared compounds was superior to used standards in inhibitory ability or selectivity. The structure activity relationship of the novel compounds was determinated from the obtained data

Preparation and in vitro screening of quartenary inhibitors of acetylcholinesterase

Preparation and in vitro screening of quarternary inhibitors of acetylcholinesterase Abstract Reversible acetylcholinesterase (AChE) inhibitors are extensively used in human medicine. Among other applications they are used as a pre-exposure treatment for the prevention of organophosphorus poisoning. For this purpose carbamate inhibitors are recently used (e.g. pyridostigmine chloride). Carbamates reversibly block AChE active site and thus protect AChE against irreversible inhibition by organophosphorus compounds. However, these drugs have many undesirable side-effects and thus there are efforts to find a more suitable alternative among reversible AChE inhibitors. In this diploma thesis, 19 potential AChE inhibitors were prepared. Their ability to inhibit AChE and butyrylcholinesterase was evaluated in vitro and compared to selective standard cholinesterase inhibitors BW284c51 and ethopropazine. None of the prepared compounds was superior to used standards in inhibitory ability or selectivity. The structure activity relationship of the novel compounds was determinated from the obtained data

Preparation and evaluation of potential drugs inhibiting mitochondrial enzymes

Preparation and evaluation of potential drugs inhibiting mitochondrial enzymes Summary in English Alzheimer's disease (AD) is the most common cause of senile dementia worldwide. Despite being subject to intensive research, the pathogenic mechanisms of AD are still not fully understood and consequently an effective treatment is yet to be developed. Although the aetiology of AD is still unknown, a build-up of amyloid-beta peptide (Aβ) is considered to play an important role in disease progression. The original amyloid cascade hypothesis proposed that insoluble extracellular plaques were responsible for the majority of Aβ toxicity. This hypothesis has since been refined, as recent data indicates that soluble intracellular oligomers are now responsible for the majority of Aβ induced toxic effects. The mitochondrial dysfunction also plays an important role in the pathophysiology of AD. Aβ was detected inside mitochondria and several mitochondrial proteins were found to interact directly with Aβ. Such interactions can affect a protein's function and cause damage to the mitochondria, which finally results in progression of AD. The background for the experimental part of this dissertation thesis was literature review summarizing current knowledge on mitochondrial proteins directly interacting with Aβ in order to..

Exploring the Chemical Space of Benzothiazole-Based DNA Gyrase B Inhibitors

doi: 10.1021/acsmedchemlett.0c00416We designed and synthesized a series of inhibitors of the bacterial enzymes DNA gyrase and DNA topoisomerase IV, based on our recently published benzothiazole-based inhibitor bearing an oxalyl moiety. To improve the antibacterial activity and retain potent enzymatic activity, we systematically explored the chemical space. Several strategies of modification were followed: varying substituents on the pyrrole carboxamide moiety, alteration of the central scaffold, including variation of substitution position and, most importantly, modification of the oxalyl moiety. Compounds with acidic, basic, and neutral properties were synthesized. To understand the mechanism of action and binding mode, we have obtained a crystal structure of compound 16a, bearing a primary amino group, in complex with the N-terminal domain of E. coli gyrase B (24 kDa) (PDB: 6YD9). Compound 15a, with a low molecular weight of 383 Da, potent inhibitory activity on E. coli gyrase (IC50 = 9.5 nM), potent antibacterial activity on E. faecalis (MIC = 3.13 mu M), and efflux impaired E. coli strain (MIC = 0.78 mu M), is an important contribution for the development of novel gyrase and topoisomerase IV inhibitors in Gram-negative bacteria.Peer reviewe

Exploring the chemical space of benzothiazole-based DNA gyrase B inhibitors

We designed and synthesized a series of inhibitors of the bacterial enzymes DNA gyrase and DNA topoisomerase IV, based on our recently published benzothiazole-based inhibitor bearing an oxalyl moiety. To improve the antibacterial activity and retain potent enzymatic activity, we systematically explored the chemical space. Several strategies of modification were followed: varying substituents on the pyrrole carboxamide moiety, alteration of the central scaffold, including variation of substitution position and, most importantly, modification of the oxalyl moiety. Compounds with acidic, basic, and neutral properties were synthesized. To understand the mechanism of action and binding mode, we have obtained a crystal structure of compound 16a, bearing a primary amino group, in complex with the N-terminal domain of E. coli gyrase B (24 kDa) (PDB: 6YD9). Compound 15a, with a low molecular weight of 383 Da, potent inhibitory activity on E. coli gyrase (IC50 = 9.5 nM), potent antibacterial activity on E. faecalis (MIC = 3.13 [micro]M), and efflux impaired E. coli strain (MIC = 0.78 [micro]M), is an important contribution for the development of novel gyrase and topoisomerase IV inhibitors in Gram-negative bacteria