Oxime reactivators of acetylcholinesterase (AChE) are used as causal antidotes for intended and unintended poisoning by organophosphate nerve agents and pesticides. Despite all efforts to develop new AChE reactivators, none of these drug candidates replaced conventional clinically used oximes. In addition to the therapeutic efficacy, determining the safety profile is crucial in preclinical drug evaluation. The exact mechanism of oxime toxicity and the structure-toxicity relationship are subjects of ongoing research, with oxidative stress proposed as a possible mechanism. In the present study, we investigated four promising bispyridinium oxime AChE reactivators, K048, K074, K075, and K203, and their ability to induce oxidative stress in vitro. Cultured human hepatoma cells were exposed to oximes at concentrations corresponding to their IC50 values determined by the MTT assay after 24 h. Their potency to generate reactive oxygen species, interfere with the thiol antioxidant system, and induce lipid peroxidation was evaluated at 1, 4, and 24 h of exposure. Reactivators without a double bond in the four-carbon linker, K048 and K074, showed a greater potential to induce oxidative stress compared with K075 and K203, which contain a double bond. Unlike oximes with a three-carbon-long linker, the number of aldoxime groups attached to the pyridinium moieties does not determine the oxidative stress induction for K048, K074, K075, and K203 oximes. In conclusion, our results emphasize that the structure of oximes plays a critical role in inducing oxidative stress, and this relationship does not correlate with their cytotoxicity expressed as the IC50 value. However, it is important to note that oxidative stress cannot be disregarded as a potential contributor to the side effects associated with oximes.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• antidota farmakologie   MeSH
• buňky Hep G2 MeSH
• cholinesterasové inhibitory toxicita   MeSH
• lidé MeSH
• organofosfáty toxicita   MeSH
• oxidační stres MeSH
• oximy farmakologie   chemie   MeSH
• pyridinové sloučeniny farmakologie   chemie   MeSH
• reaktivátory cholinesterázy * farmakologie   chemie   MeSH
• uhlík MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• antidota MeSH
• cholinesterasové inhibitory MeSH
• organofosfáty MeSH
• oximy MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterázy * MeSH
• uhlík MeSH

Twenty-four novel compounds bearing tetrahydroacridine and N-propargyl moieties have been designed, synthesised, and evaluated in vitro for their anti-cholinesterase and anti-monoamine oxidase activities. Propargyltacrine 23 (IC50 = 21 nM) was the most potent acetylcholinesterase (AChE) inhibitor, compound 20 (IC50 = 78 nM) showed the best inhibitory human butyrylcholinesterase (hBChE) profile, and ligand 21 afforded equipotent and significant values on both ChEs (human AChE [hAChE]: IC50 = 0.095 ± 0.001 µM; hBChE: IC50 = 0.093 ± 0.003 µM). Regarding MAO inhibition, compounds 7, 15, and 25 demonstrated the highest inhibitory potential towards hMAO-B (IC50 = 163, 40, and 170 nM, respectively). In all, compounds 7, 15, 20, 21, 23, and 25 exhibiting the most balanced pharmacological profile, were submitted to permeability and cell viability tests. As a result, 7-phenoxy-N-(prop-2-yn-1-yl)-1,2,3,4-tetrahydroacridin-9-amine hydrochloride (15) has been identified as a permeable agent that shows a balanced pharmacological profile [IC50 (hAChE) = 1.472 ± 0.024 µM; IC50 (hBChE) = 0.659 ± 0.077 µM; IC50 (hMAO-B) = 40.39 ± 5.98 nM], and consequently, as a new hit-ligand that deserves further investigation, in particular in vivo analyses, as the preliminary cell viability test results reported here suggest that this is a relatively safe therapeutic agent.

• Klíčová slova
• Alzheimer’s disease, Cholinesterase inhibitor, monoamine oxidase inhibitor, propargyl amines, tacrine,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• Alzheimerova nemoc * farmakoterapie   MeSH
• aminy MeSH
• butyrylcholinesterasa * metabolismus   MeSH
• cholinesterasové inhibitory farmakologie   terapeutické užití   MeSH
• inhibitory MAO farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• monoaminoxidasa MeSH
• oxidoreduktasy MeSH
• racionální návrh léčiv MeSH
• takrin terapeutické užití   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• aminy MeSH
• butyrylcholinesterasa * MeSH
• cholinesterasové inhibitory MeSH
• inhibitory MAO MeSH
• ligandy MeSH
• monoaminoxidasa MeSH
• oxidoreduktasy MeSH
• takrin MeSH

The increasing risk of radiation exposure underlines the need for novel radioprotective agents. Hence, a series of novel 1-(2-hydroxyethyl)piperazine derivatives were designed and synthesized. Some of the compounds protected human cells against radiation-induced apoptosis and exhibited low cytotoxicity. Compared to the previous series of piperazine derivatives, compound 8 exhibited a radioprotective effect on cell survival in vitro and low toxicity in vivo. It also enhanced the survival of mice 30 days after whole-body irradiation (although this increase was not statistically significant). Taken together, our in vitro and in vivo data indicate that some of our compounds are valuable for further research as potential radioprotectors.

• Klíčová slova
• cytotoxicity, maximum tolerated dose, piperazine, radiation-protective agents, synthesis de novo,
• MeSH
• analýza přežití MeSH
• ionizující záření MeSH
• lidé MeSH
• maximální tolerovaná dávka MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• piperaziny aplikace a dávkování   škodlivé účinky   chemie   farmakologie   MeSH
• radioprotektivní látky aplikace a dávkování   škodlivé účinky   chemie   farmakologie   MeSH
• viabilita buněk účinky léků   účinky záření   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• piperaziny MeSH
• radioprotektivní látky MeSH

Tacrine was the first drug to be approved for Alzheimer's disease (AD) treatment, acting as a cholinesterase inhibitor. The neuropathological hallmarks of AD are amyloid-rich senile plaques, neurofibrillary tangles, and neuronal degeneration. The portfolio of currently approved drugs for AD includes acetylcholinesterase inhibitors (AChEIs) and N-methyl-d-aspartate (NMDA) receptor antagonist. Squaric acid is a versatile structural scaffold capable to be easily transformed into amide-bearing compounds that feature both hydrogen bond donor and acceptor groups with the possibility to create multiple interactions with complementary sites. Considering the relatively simple synthesis approach and other interesting properties (rigidity, aromatic character, H-bond formation) of squaramide motif, we combined this scaffold with different tacrine-based derivatives. In this study, we developed 21 novel dimers amalgamating squaric acid with either tacrine, 6-chlorotacrine or 7-methoxytacrine representing various AChEIs. All new derivatives were evaluated for their anti-cholinesterase activities, cytotoxicity using HepG2 cell line and screened to predict their ability to cross the blood-brain barrier. In this contribution, we also report in silico studies of the most potent AChE and BChE inhibitors in the active site of these enzymes.

• Klíčová slova
• 6-chlorotacrine, 7-methoxytacrine, Alzheimer’s disease, bis(7)-tacrine, cholinesterases, in silico, in vitro, squaramides, tacrine,
• MeSH
• acetylcholinesterasa metabolismus   MeSH
• butyrylcholinesterasa metabolismus   MeSH
• chinin analogy a deriváty   chemie   farmakologie   MeSH
• cholinesterasové inhibitory chemická syntéza   chemie   farmakologie   MeSH
• kinetika MeSH
• lidé MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• takrin chemie   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholinesterasa MeSH
• butyrylcholinesterasa MeSH
• chinin MeSH
• cholinesterasové inhibitory MeSH
• squaramide MeSH Prohlížeč
• takrin MeSH