Quinoline containing chalcone derivatives as cholinesterase inhibitors and their in silico modeling studies.

Cholinesterases (ChEs) play a vital role in regulating cholinergic transmission. Inhibition of ChEs is thought to be an emerging and useful therapeutic target for neurodegenerative disorders through restoration of acetylcholine (ACh) levels in the brain (e.g. Alzheimer's disease). To increase the chemical diversity of cholinesterase inhibitors, a series of quinoline chalcones derivatives were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) isoenzymes. All tested compounds (4a-1; 5a-s) exhibited inhibitory activities against AChE and BChE to a considerable extent. Molecular docking studies were performed by using homology models on both AChE and BChE isoenzymes with the aim of exploring probable binding modes of the most potent inhibitor. In order to evaluate drug likeness of newly tested molecules, we carried out in-silico ADME evaluation. All compounds displayed favourable ADME findings which predict good oral bioavailability of these derivatives. Due to an excellent ADME profile the tested compounds were predicted to be safer which can be considered as novel cholinesterase inhibitors.

New cholinesterase inhibitors for Alzheimer's disease: Structure activity relationship, kinetics and molecular docking studies of 1-butanoyl-3-arylthiourea derivatives.

Highly progressive neurodegenerative disorder generally known as Alzheimer's disease (AD), is a type of dementia, which is very common in elderly. The most common symptoms may include loss of memory along with disturbed behavioral and cognitive functions. Until now, only 4 cholinesterase (ChE) inhibitors are approved by FDA for symptomatic treatment of AD. Aroyl thiourea derivatives are well known bioactive organic molecules containing carbonyl and thiocarbonyl functional groups. Here, total 14 different thiourea derivatives (3a-3n) were synthesized and characterized by NMR, FTIR and X-ray crystallographic techniques. The synthesized compounds displayed varying inhibition activities on both acetylcholineterase (AChE) and butyrylcholinesterase (BuChE) enzymes. Among all compounds, 3b and 3e were potent inhibitors of AChE (IC50 ±â€¯SEM = 8.92 ±â€¯1.03 µM) and BuChE (IC50 ±â€¯SEM = 6.96 ±â€¯0.961 µM) respectively. Enzyme kinetic studies showed that 3b exhibited uncompetitive binding with AChE while 3e demonstrated a mixed inhibition of BuChE. Molecular docking studies on AChE showed that 3b got binding interaction with Trp86 and Tyr337 while 3e showed binding affinity with Trp82 and His438 when docked with BuChE. The obtained results indicated that these thiourea derivatives could be considered as potential candidates to treat AD.

Synthesis, molecular modelling and biological evaluation of tetrasubstituted thiazoles towards cholinesterase enzymes and cytotoxicity studies.

Alzheimer is a neurodegenerative disease and requires the development of new scaffold to treat it. In this regard, thiazoles derivative are playing their significant role. In the current research paper we have focused our attention for the development of tetrasubstituted thiazole (3a-h) derivatives using domino synthesis by mixing the thiourea as a precursor, with acetophenone in the presence of iodine and tosic acid in DMSO and refluxed for 12-22 h. The structures of the newly synthesized compounds were confirmed by FTIR, 1H NMR, 13C NMR and EIMS analysis. Thiazole derivatives were analyzed for their biological significances against acetyl and butylcholinesterase enzymes and compound 3b and 3d were found more active against these enzyme, respectively. The mode of inhibition was determined for the potent compounds against both the enzymes. Moreover, the molecular docking studies were carried out to explore the interactive behavior of the compounds within the active pocket of enzymes. Furthermore, the derivatives (3a-h) were evaluated for their anticancer potential against HeLa cancer cell lines. Most potent inhibition was observed by compound 3b.

Modification of Bischler-Möhlau indole derivatives through palladium catalyzed Suzuki reaction as effective cholinesterase inhibitors, their kinetic and molecular docking studies.

Due to the immense importance of aryl indole nucleus, herein we report the palladium-catalyzed arylation of N-substituted 2-aryl indole utilizing Suzuki-Miyaura cross coupling methodology. The biological screening for cholinesterase inhibition of the resulted biaryl indole moieties was carried out to evaluate their pharmacological potential, expecting to involve the development of new therapeutics for various inflammatory, cardiovascular, gastrointestinal and neurological diseases. This research work also involved the use of utilization of microwave-assisted organic synthesis (MAOS) for the synthesis of Bischler-Möhlau indole which is further biarylated via palladium-catalyzed cross coupling reaction. All the synthetic compounds (3a-n) were tested for cholinesterase inhibition and exhibited high level of AChE inhibitory activities. Interestingly, compounds 3m and 3n were found to be dual inhibitors, however, remaining compound exhibited no inhibitory activity against BChE. The biological potential of the resulted compounds was explained on the basis of molecular docking studies, performed against AChE and BChE, exploring the probable binding modes of most potent inhibitors.

Cholinesterases inhibition and molecular modeling studies of piperidyl-thienyl and 2-pyrazoline derivatives of chalcones.

Super-activation of cholinesterases (acetylcholinesterase and butyrylcholinesterase) are linked to various neurological problems most precisely Alzheimer's disease (AD), which leads to senile dementia. Therefore, cholinesterases (AChE & BChE) inhibition are considered as a promising strategy for the treatment of Alzheimer's disease. FDA approved drugs for the treatment of AD, belong to a group of cholinesterase inhibitors. However, none of them is able to combat or completely abrogate the disease progression. Herein, we report a series of newly synthesized chalcone derivatives with anti-AD potential. For this purpose, a series of piperidyl-thienyl and 2-pyrazoline derivatives of chalcones were tested for their cholinesterases (AChE & BChE) inhibitory activity. All compounds were found as selective inhibitor of AChE. In piperidyl chalcones derivatives compound 1e having IC50 of 0.16 ± 0.008 µM and 2m in 2-pyrazoline chalcones with IC50 of 0.13 ± 0.006 µM, were found to be the most potent inhibitors of AChE, exhibiting ≈142 and ≈ 173-fold greater inhibitory potential compared to the reference inhibitor i.e., Neostigmine (IC50 ± SEM = 22.2 ± 3.2 µM). Molecular docking studies of most potent inhibitors were carried out to investigate the binding interactions inside the active site. Molecular docking study revealed that potent compounds and co-crystalized ligand had same binding orientation within the active site of target enzyme. Most of these compounds are selective inhibitors of AChE with a potential use against progressive neurodegenerative disorder and age related problems.

Identification of novel chromone based sulfonamides as highly potent and selective inhibitors of alkaline phosphatases.

A new series of structurally diverse chromone containing sulfonamides has been developed. Crystal structures of three representative compounds (2a, 3a and 4a) in the series are reported. All compounds were screened for their inhibitory potential against alkaline phosphatases (ALPs). Two main classes of ALP isozymes were selected for this study, the tissue non-specific alkaline phosphatase (TNALP) from bovine and porcine source and the tissue-specific intestinal alkaline phosphatases (IALPs) from bovine source. All sulfonamide compounds had a marked preference for IALP (K(i), up to 0.01 ± 0.001 µM) over TNALPs. Kinetics studies of the compounds showed competitive mode of inhibition. Molecular docking studies were carried out in order to characterize the selective inhibition of the compounds. An additional interesting aspect of these chromone sulfonamides is their inhibitory activity against ecto-5'-nucleotidase enzyme.