Publications by authors named "Hrabinova M"

We aimed to prepare novel dibenzo [a,d][7]annulen derivatives that act on N-methyl-d-aspartate (NMDA) receptors with potential neuroprotective effects. Our approach involved modifying the tropane moiety of MK-801, a potent open-channel blocker known for its psychomimetic side effects, by introducing a seven-membered ring with substituted base moieties specifically to alleviate these undesirable effects. Our in silico analyses showed that these derivatives should have high gastrointestinal absorption and cross the blood-brain barrier (BBB).

View Article and Find Full Text PDF

The investigation into human butyrylcholinesterase (BChE) inhibitors as therapeutic agents for Alzheimer's disease (AD) holds significant promise, addressing both symptomatic relief and disease progression. In the pursuit of novel drug candidates with a selective BChE inhibition pattern, we focused on naturally occurring template structures, specifically Amaryllidaceae alkaloids of the carltonine-type. Herein, we explored a series of compounds implementing an innovative chemical scaffold built on the 3- and 4-benzyloxy-benzylamino chemotype.

View Article and Find Full Text PDF
Article Synopsis
  • * Researchers investigated 29 novel reactivators, emphasizing the zwitterionic strategy and discovering 17 mono-oxime and nine bisoxime reactivators that show significant promise.
  • * The top compounds, particularly 55, 57, and 58, outperform existing clinical antidotes like pralidoxime in reactivating potency, highlighting their potential for treating OP poisoning more effectively.
View Article and Find Full Text PDF
Article Synopsis
  • Researchers are exploring new drug options for Alzheimer's disease by focusing on multi-target directed ligands (MTDLs) that can address the disease's complexity more effectively.
  • They modified the drug amiridine, a known cholinesterase inhibitor, by combining it with other compounds to create MTDLs that also possess additional benefits, such as NMDA receptor affinity and antioxidant effects.
  • The study's findings, particularly regarding a top compound called 5d, suggest that these new amiridine-based drugs could offer a broader therapeutic approach for treating Alzheimer's disease.
View Article and Find Full Text PDF
Article Synopsis
  • A-234 is a new generation nerve agent implicated in the poisoning of a former Russian spy in 2018, leading to its inclusion in the Chemical Weapons Convention.
  • Research indicates limited information on A-234's chemical properties, biological effects, and effective treatments, with findings showing the agent is stable but exhibits significant toxicity similar to VX.
  • Current antidotes, especially oximes like HI-6 and methoxime, show minimal effectiveness in reactivating inhibited enzymes, while atropine and diazepam provide better therapeutic outcomes against A-234 lethality.
View Article and Find Full Text PDF
Article Synopsis
  • Tacrine (THA) has been phased out due to safety concerns but is still used as a framework in drug development for its effectiveness against multiple targets, although its potential for liver toxicity is a major concern.
  • Researchers developed 30 new derivatives focusing on minimizing hepatotoxicity while maintaining anticholinesterase properties and targeting specific NMDA receptor subtypes, leading to the identification of two promising candidates, I-52 and II-52.
  • Compound I-52 was highlighted as a lead candidate, demonstrating minimal toxicity, favorable neuroprotective effects in behavioral tests, and lower hepatotoxicity compared to traditional THA-based drugs.
View Article and Find Full Text PDF

"Novichok" refers to a new group of nerve agents called the A-series agents. Their existence came to light in 2018 after incidents in the UK and again in 2020 in Russia. They are unique organophosphorus-based compounds developed during the Cold War in a program called Foliant in the USSR.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is a complex disease with an unknown etiology. Available treatments, limited to cholinesterase inhibitors and -methyl-d-aspartate receptor (NMDAR) antagonists, provide symptomatic relief only. As single-target therapies have not proven effective, rational specific-targeted combination into a single molecule represents a more promising approach for treating AD, and is expected to yield greater benefits in alleviating symptoms and slowing disease progression.

View Article and Find Full Text PDF

Organophosphorus compounds (OPs) involving life-threatening nerve agents (NA) have been known for several decades. Despite a clear mechanism of their lethality caused by the irreversible inhibition of acetylcholinesterase (AChE) and manifested via overstimulation of peripheral nicotinic and muscarinic acetylcholine (ACh) receptors, the mechanism for central neurotoxicity responsible for acute or delayed symptoms of the poisoning has not been thoroughly uncovered. One of the reasons is the lack of a suitable model.

View Article and Find Full Text PDF

Butyrylcholinesterase (BChE) is one of the most frequently implicated enzymes in the advanced stage of Alzheimer's disease (AD). As part of our endeavors to develop new drug candidates for AD, we have focused on natural template structures, namely the Amaryllidaceae alkaloids carltonine A and B endowed with high BChE selectivity. Herein, we report the design, synthesis, and in vitro evaluation of 57 novel highly selective human BChE (hBChE) inhibitors.

View Article and Find Full Text PDF

Insecticides represent the most crucial element in the integrated management approach to malaria and other vector-borne diseases. The evolution of insect resistance to long-used substances and the toxicity of organophosphates (OPs) and carbamates are the main factors contributing to the development of new, environmentally safe pesticides. In our work, fourteen compounds of 7-methoxytacrine-tacrine heterodimers were tested for their insecticidal effect.

View Article and Find Full Text PDF

Kynurenic acid is a neuroprotective metabolite of tryptophan formed by kynurenine aminotransferase (KAT) catalyzed transformation of kynurenine. However, its high brain levels are associated with cognitive deficit and with the pathophysiology of schizophrenia. Although several classes of KAT inhibitors have been published, the search for new inhibitor chemotypes is crucial for the process of finding suitable clinical candidates.

View Article and Find Full Text PDF

One undescribed indole alkaloid together with twenty-two known compounds have been isolated from aerial parts of Vinca minor L. (Apocynaceae). The chemical structures of the isolated alkaloids were determined by a combination of MS, HRMS, 1D, and 2D NMR techniques, and by comparison with literature data.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is a multifactorial neurodegenerative condition of the central nervous system (CNS) that is currently treated by cholinesterase inhibitors and the -methyl-d-aspartate receptor antagonist, memantine. Emerging evidence strongly supports the relevance of targeting butyrylcholinesterase (BuChE) in the more advanced stages of AD. Within this study, we have generated a pilot series of compounds (-) structurally inspired from belladine-type Amaryllidaceae alkaloids, namely carltonine A and B, and evaluated their acetylcholinesterase (AChE) and BuChE inhibition properties.

View Article and Find Full Text PDF

The search for novel and effective therapeutics for Alzheimer's disease (AD) is the main quest that remains to be resolved. The goal is to find a disease-modifying agent able to confront the multifactorial nature of the disease positively. Herewith, a family of huprineY-tryptophan heterodimers was prepared, resulting in inhibition of cholinesterase and neuronal nitric oxide synthase enzymes, with effect against amyloid-beta (Aβ) and potential ability to cross the blood-brain barrier.

View Article and Find Full Text PDF

Since 2002, no clinical candidate against Alzheimer's disease has reached the market; hence, an effective therapy is urgently needed. We followed the so-called "multitarget directed ligand" approach and designed 36 novel tacrine-phenothiazine heterodimers which were evaluated for their anticholinesterase properties. The assessment of the structure-activity relationships of such derivatives highlighted compound as a potent and selective acetylcholinesterase inhibitor with IC = 8 nM and as a potent butyrylcholinesterase inhibitor with IC = 15 nM.

View Article and Find Full Text PDF

The authors report on the synthesis and biological evaluation of new compounds whose structure combines tacrine and indole moieties. Tacrine-indole heterodimers were designed to inhibit cholinesterases and β-amyloid formation, and to cross the blood-brain barrier. The most potent new acetylcholinesterase inhibitors were compounds and (IC = 25 and 39 nM, respectively).

View Article and Find Full Text PDF

Current palliative pharmacotherapy of Alzheimer's disease based on the cholinergic hypothesis led to the development of four cholinesterase inhibitors. These compounds can bring prolongation of the symptom-free period in some patients. This is the first report directly comparing donepezil and rivastigmine plasma and brain levels in study.

View Article and Find Full Text PDF

To date, the only treatments developed for poisoning by organophosphorus compounds, the most toxic chemical weapons of mass destruction, have exhibited limited efficacy and versatility. The available causal antidotes are based on reactivation of the enzyme acetylcholinesterase (AChE), which is rapidly and pseudo-irreversibly inhibited by these agents. In this study, we developed a novel series of monoquaternary reactivators combining permanently charged moieties tethered to position 6- of 3-hydroxypyridine-2-aldoxime reactivating subunit.

View Article and Find Full Text PDF

Twenty known Amaryllidaceae alkaloids of various structural types, and one undescribed alkaloid of narcikachnine-type, named narcieliine (3), have been isolated from fresh bulbs of Zephyranthes citrina. The chemical structures of the isolated alkaloids were elucidated by a combination of MS, HRMS, 1D and 2D NMR, and CD spectroscopic techniques, and by comparison with literature data. The absolute configuration of narcieliine (3) has also been determined.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is a complex disorder with unknown etiology. Currently, only symptomatic therapy of AD is available, comprising cholinesterase inhibitors and -methyl-d-aspartate (NMDA) receptor antagonists. Drugs targeting only one pathological condition have generated only limited efficacy.

View Article and Find Full Text PDF

Alzheimer's disease is a progressive brain disorder with characteristic symptoms and several pathological hallmarks. The concept of "one drug, one target" has not generated any new drugs since 2004. The new era of drug development in the field of AD builds upon rationally designed multi-target directed ligands that can better address the complexity of AD.

View Article and Find Full Text PDF

Berberine, a naturally occurring compound, possesses an interesting multipotent pharmacological profile potentially applicable for Alzheimer's disease (AD) treatment. In this study, a series of novel 22 berberine derivatives was developed and tested in vitro. Berberine core was substituted at position 9-O of its aromatic ring region.

View Article and Find Full Text PDF

Thirteen known (- and ) and three previously undescribed Amaryllidaceae alkaloids of belladine structural type, named carltonine A-C (-), were isolated from bulbs of cv. Carlton (Amaryllidaceae) by standard chromatographic methods. Compounds isolated in sufficient amounts, and not tested previously, were evaluated for their in vitro acetylcholinesterase (AChE; E.

View Article and Find Full Text PDF

β-secretase (BACE1) has been regarded as a prime target for the development of amyloid beta (Aβ) lowering drugs in the therapy of Alzheimer´s disease (AD). Although the enzyme was discovered in 1991 and helped to formulate the Aβ hypothesis as one of the very important features of AD etiopathogenesis, progress in AD treatment utilizing BACE1 inhibitors has remained limited. Moreover, in the last years, major pharmaceutical companies have discontinued clinical trials of five BACE1 inhibitors that had been strongly perceived as prospective.

View Article and Find Full Text PDF