Synthesis and bioactivities of 1-(4-hydroxyphenyl)-2-((heteroaryl)thio)ethanones as carbonic anhydrase I, II and acetylcholinesterase inhibitors

Synthesis and Inhibitor Effect Novel Alkoxymethyl Derivatives of Dihetero Cycloalkanes on Carbonic Anhydrase and Acetylcholinesterase

1,3-Diheterocycloalkanes derivatives are important starting materials in fine organic synthesis. These compounds can be widely used in various fields such as industry, medicine, biotechnology and chemical technology. The paper is focused on synthesis and study of alkoxymethyl derivatives of diheterocycloalkanes (M1-M15) and inhibition effect on carbonic anhydrase and acetylcholinesterase. The structures of compounds were confirmed by 1H and 13C NMR spectroscopy. Also, in this study alkoxymethyl derivatives of diheterocycloalkanes were assessed for their influence on various metabolic enzymes, including acetylcholinesterase (AChE) and human carbonic anhydrase isoenzymes (hCA I and hCA II). The results demonstrated that all these compounds exhibited potent inhibitory effects on all the target enzymes, surpassing the standard inhibitors, as evidenced by their IC50 and Ki values. The Ki values for the compounds concerning AChE, hCA I, and hCA II enzymes were in the ranges of 1.02±0.17-8.38±1.02, 15.30±3.15-58.14±5.17 and 24.05±3.70-312.94±27.24 nM, respectively.

Organohalogen chalcones: design, synthesis, ADMET prediction, molecular dynamics study and inhibition effect on acetylcholinesterase and carbonic anhydrase

In an effort to discover potential acetylcholinesterase (AChE) and carbonic anhydrase (CA) inhibitors, a novel series of organohalogen chalcone derivatives (12-20, 23-30) was synthesized, and their chemical structures were characterized by spectral analysis. They showed a highly potent inhibition effect on AChE and hCAs (Ki values range from 5.07 ± 0.062 to 65.53 ± 4.36 nM for AChE, 13.54 ± 2.55 to 94.11 ± 10.39 nM for hCA I, and 5.21 ± 0.54 to 57.44 ± 3.12 nM for hCA II). In addition, the chalcone derivatives with the highest inhibitor score docked into the active site of the indicated metabolic enzyme receptors, and their absorption, metabolism, and toxic properties were evaluated according to ADMET's estimation.Compounds 16 and 19 exhibited the highest inhibition score, emerged as lead compounds, and inspired the development of more potent compounds.

Pyrimidines: Molecular docking and inhibition studies on carbonic anhydrase and cholinesterases

Alzheimer's disease (AD) is a neurodegenerative disorder. The disease is characterized by dementia, memory impairment, cognitive impairment, and speech impairment. Cholinesterases (ChEs; AChE, acetylcholinesterase and BChE, butyrylcholinesterase) inhibitors and their benefits of cholinergic replacement in the treatment of AD have been researched and documented by scientists in various ways to date. Recent studies prove that human carbonic anhydrases (hCAs) are also one of the important targets in the treatment of AD. Therefore, the development of new agents that can simultaneously modulate the various mechanisms or targets involved in the AD pathway may be a powerful strategy to treat AD, the current disease. Considering these data, the effects of the pyrimidines (1-7) were investigated in this study for the discovery and development of multitargeted ChEs and hCAs inhibitors associated with AD. In addition, the molecular docking analysis of the 4-amino-2-choloropyrimidine (2) was performed to understand the binding interactions on the active site of the enzyme. All compounds (1-7) showed satisfactory enzyme inhibitory potency in micromolar concentrations against AChE, BChE, hCAI, and hCAII with K_I values ranging from 0.099 to 0.241 μM, from 1.324 to 3.418 μM, from 0.201 to 0.884 μM, from 1.867 to 3.913 μM, respectively. Due to their ChEs and hCAs inhibition, these compounds (1-7) may be considered as leads for investigations in neurodegenerative diseases. All these results revealed that the 4-amino-5,6-dichloropyrimidine (7) (K_I value of 0.201 ± 0.041 μM for hCA I), the 4-amino-6-hydroxypyrimidine (4) (K_I value of 1.867 ± 0.296 μM for hCA II), the 4-amino-5,6-dichloropyrimidine (7) (K_I value of 0.099 ± 0.008 μM for AChE), and the 4-amino-2-chloropyrimidine (2) (K_I value of 1.324 ± 0.273 μM for BChE) from the pyrimidines in this series were the most promising derivatives, as they exhibited a good multifunctional inhibition at all experimental levels and in the in silico validation against these enzymes, for the treatment of AD.

Benzimidazolium Salts Containing Trifluoromethoxybenzyl: Synthesis, Characterization, Crystal Structure, Molecular Docking Studies and Enzymes Inhibitory Properties

The method for producing 4-trifluoromethoxybenzyl substituted benzimidazolium salts is described in this article. The method is based on the reaction of 4-trifluoromethoxybenzyl substituent alkylating agent with 1-alkylbenzimidazole. This method yielded 1-(4-trifluoromethoxybenzyl)-3-alkylbenzimidazolium bromide salts. These benzimidazolium salts were characterized by using ¹ H-NMR, ¹³ C-NMR, FT-IR spectroscopy, and elemental analysis techniques. The crystal structure of 1f was enlightened by single crystal X-ray diffraction studies. Also, the enzyme inhibition effects of the synthesised compounds were investigated. They demonstrated highly potent inhibition effect on acetylcholinesterase (AChE) and carbonic anhydrases (hCAs) (K_i values are in the range of 7.24±0.99 to 39.12±5.66 nM, 5.57±0.96 to 43.07±11.76 nM, and 4.38±0.43 to 18.68±3.60 nM for AChE, hCA I, and hCA II, respectively). In molecular docking study, the interactions of active compounds showing activity against AChE and hCAs enzymes were examined. The most active compound 1f has -10.90 kcal/mol binding energy value against AChE enzyme, and the potential structure compound 1e, which has activity against hCA I and hCA II enzymes, was -7.51 and -8.93 kcal/mol, respectively.

The palladium-based complexes bearing 1,3-dibenzylbenzimidazolium with morpholine, triphenylphosphine, and pyridine derivate ligands: synthesis, characterization, structure and enzyme inhibitions

The palladium-based complexes bearing N-heterocyclic carbene (NHC) ligand have long attracted attention as active catalysts for many catalytic reactions. Recently, the biological activities of these complexes, which are stable to air and moisture, have also been wondered. With the aim, we report the synthesis of a series of (NHC)Pd(Br2)(L) complexes (NHC: 1,3-dibenzylbenzimidazolium, L: morpholine, triphenylphosphine, pyridine, 3-chloropyridine, and 2-aminopyridine). All complexes were characterized by NMR (1H and 13C), FTIR spectroscopic and elemental analysis techniques. In addition, the single crystal structures of the complex 3, 4, and 6 were determined through single crystal x-ray crystallographic method. Furthermore, the carbonic anhydrase I and II isoenzymes (hCAs) and acetylcholinesterase (AChE) inhibition effects of these palladium-based complexes bearing NHC ligand were investigated. They showed highly potent inhibition effect with Ki values are between 10.06 ± 1.49-68.56 ± 11.53 nM for hCA I isoenzyme, 7.74 ± 0.66 to 49.39 ± 6.50 nM for hCA II isoenzyme and 22.83 ± 3.21 to 64.09 ± 9.05 nM for AChE enzyme.

Isolation of Some Phenolic Compounds from Plantago subulata L. and Determination of Their Antidiabetic, Anticholinesterase, Antiepileptic and Antioxidant Activity

In the current study, some phenolic compounds, including acteoside, isoacteoside, echinacoside, and arenarioside purified and characterized from Plantago subulata. These compounds were tested for its antioxidant potential, including Fe³⁺ and Cu²⁺ reductive ability and Fe²⁺ chelating effects. The inhibitory effects of isolated phenolic compounds were tested towards human carbonic anhydrase I and II isoenzymes (hCA I and hCA II), butyrylcholinesterase (BChE) acetylcholinesterase (AChE), aldose reductase (AR) and α-glycosidase (α-gly). K_i values were found these compounds in range of 0.24±0.05-1.38±0.34 μM against hCA I, 0.194±0.018-1.03±0.06 μM against hCA II, 0.043±0.01-0.154±0.02 μM against AChE, 3.92±1.08-11.93±4.45 μM against BChE, 0.082±0.0008-1.68±0.42 μM against AR, and 6.93±2.74-17.17±6.70 μM against α-glycosidase. As a result, isolated compounds displayed inhibition effects against studied all metabolic enzymes. They are promising candidates for treating disorders like Alzheimer's disease, diabetes mellitus, glaucoma, leukemia, and epilepsy.

Cytotoxic effect, enzyme inhibition, and in silico studies of some novel N-substituted sulfonyl amides incorporating 1,3,4-oxadiazol structural motif

Abstract

The acetylcholinesterase and carbonic anhydrase inhibitors (AChEIs and hCAIs) remain key therapeutic agents for many bioactivities such as anti-Alzheimer and antiobesity antiepileptic, anticancer, antiinfective, antiglaucoma, and diuretic effects. Here, it has been attempted to discover novel multi-target AChEIs and hCAIs that are highly potent, orally bioavailable, may be brain penetrant, and have higher effectiveness at lower doses than tacrine and acetazolamide. After detailed investigations both in vitro and in silico, novel N-substituted sulfonyl amide derivatives (6a–j) were determined to be highly potent inhibitors for AChE and hCAs (K_Is are in the range of 23.11–52.49 nM, 18.66–59.62 nM, and 9.33–120.80 nM for AChE, hCA I, and hCA II, respectively). Moreover, according to the cytotoxic effect studies, such as the ADME-Tox, cortex neuron cells, and neuroblastoma SH-SY5Y cell line, compounds 6a, 6d, and 6h, which are the most potent representative versus the target enzymes, were identified as orally bioavailable, highly selective, and brain preferentially distributed AChEIs and hCAIs. The docking studies revealed precise binding modes between 6a, 6d, and 6h and hCA II, hCA I, and AChE, respectively. The results presented here might provide a solid basis for further investigation into more potent AChEIs and hCAIs.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11030-022-10422-8.

New Pd(II) complexes of the bisthiocarbohydrazones derived from isatin and disubstituted salicylaldehydes: Synthesis, characterization, crystal structures and inhibitory properties against some metabolic enzymes

Pd(II) complexes (Pd1, Pd2, and Pd3) were synthesized for the first time using asymmetric isatin bisthiocarbohydrazone ligands and PdCl₂(PPh₃)₂. All complexes were characterized by a range of spectroscopic and analytical techniques. The molecular structures of Pd1 and Pd3 have been determined by single-crystal X-ray diffraction analysis. The complexes are diamagnetic and exhibit square planar geometry. The asymmetric isatin bisthiocarbohydrazone ligands coordinate to Pd(II) ion in a tridentate manner, through the phenolic oxygen, imine nitrogen and thiol sulfur, forming five- and six-membered chelate rings within their structures. The fourth coordination site in these complexes is occupied by PPh₃ (triphenylphosphine). The free ligands and their Pd(II) complexes were evaluated for their carbonic anhydrase I, II (hCAs) and acetylcholinesterase (AChE) inhibitor activities. They showed a highly potent inhibition effect on AChE and hCAs. K_i values are in the range of 9 ± 0.6 - 30 ± 5.4 nM for AChE, 7 ± 0.5 - 16 ± 2.2 nM for hCA I and 3 ± 0.3-24 ± 1.9 nM for hCA II isoenzyme. The results clearly demonstrated that the ligands and their Pd(II) complexes effectively inhibited the used enzymes.

Synthesis and some enzyme inhibition effects of isoxazoline and pyrazoline derivatives including benzonorbornene unit

Four new and four known isoxazoline derivatives were synthesized from the reactions of benzonorbornadiene with nitrile oxides formed from the corresponding benzaldehydes. Three new and one known pyrazoline derivatives were also synthesized from the reactions of the benzonorbornadiene with nitrile imines formed from the corresponding compounds. The synthesized nitrogen-based novel heterocyclic compounds were evaluated against the human carbonic anhydrase isoenzymes I and II (hCA I and hCA II), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes. The synthesized nitrogen-based novel heterocyclic compounds showed IC₅₀ values in the range of 2.69-7.01 against hCA I, 2.40-4.59 against hCA II, 0.81-1.32 µM against AChE, and 20.83-1.70 µM against BChE enzymes. On the contrary, nitrogen-based novel heterocyclic compounds demonstrated K_i values between 2.93 ± 0.59-8.61 ± 1.39 against hCA I, 2.05 ± 0.62-4.97 ± 0.95 against hCA II, 0.34 ± 0.02-0.92 ± 0.17 nM against AChE, and 0.50 ± 0.04-1.20 ± 0.16 µM against BChE enzymes. The synthesized nitrogen-based novel heterocyclic compounds exhibited effective inhibition profiles against both indicated metabolic enzymes. These results may contribute to the development of new drugs particularly to treat some disorders, which are widespread in the world including glaucoma and Alzheimer's diseases.

Discovery of sulfadrug-pyrrole conjugates as carbonic anhydrase and acetylcholinesterase inhibitors

Human carbonic anhydrase (hCA) isoenzymes are zinc ion-containing, widespread metalloenzymes and they classically play a role in pH homeostasis maintenance. CA inhibitors suppress the CA activity and their usage has been clinically established as antiglaucoma agents, antiepileptics, diuretics, and in some other disorders. Alzheimer's disease (AD) is a slowly progressive neurodegenerative disorder and a fatal disease of the brain. An advanced method to cure AD includes the strategy to design acetylcholinesterase (AChE) inhibitors. A novel series of pyrrole-3-one derivatives containing sulfa drugs (5a-i) were determined to be highly potent inhibitors for AChE and hCA I and hCA II (inhibitory constant [K_i ] values are in the range of 6.50 ± 1.02-37.46 ± 4.12 nM, 1.20 ± 0.19-44.21 ± 1.09 nM, and 8.93 ± 1.58-46.86 ± 8.41 nM for AChE, hCA I, and hCA II, respectively). The designed compounds often show a more effective inhibition than the chemicals used as the standard. Among these compounds, 5f was the most effective compound against hCA I, and compound 5e was the most effective compound against hCA II. It was determined that compound 5c was the most effective inhibitor for AChE.

Novel metabolic enzyme inhibitors designed through the molecular hybridization of thiazole and pyrazoline scaffolds

New hybrid thiazolyl-pyrazoline derivatives (4a-k) were obtained through a facile and versatile synthetic procedure, and their inhibitory effects on the human carbonic anhydrase (hCA) isoforms I and II as well as on acetylcholinesterase (AChE) were determined. All new thiazolyl-pyrazolines showed activity at nanomolar levels as hCA I, hCA II, and AChE inhibitors, with K_I values in the range of 13.35-63.79, 7.01-115.80, and 17.89-48.05 nM, respectively. 1-[4-(4-Cyanophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4f) and 1-(4-phenylthiazol-2-yl)-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4a) against hCAs and 1-[4-(4-chlorophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4d) and 1-[4-(4-nitrophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4b) against AChE were identified as highly potent inhibitors, superior to the standard drugs, acetazolamide and tacrine, respectively. Compounds 4a-k were also evaluated for their cytotoxic effects on the L929 mouse fibroblast (normal) cell line. Moreover, a comprehensive ligand-receptor interaction prediction was performed using the ADME-Tox, Glide XP, and MM-GBSA modules of the Schrödinger Small-Molecule Drug Discovery Suite to elucidate the potential binding modes of the new hybrid inhibitors against these metabolic enzymes.

Synthesis of N-alkylated pyrazolo[3,4-d]pyrimidine analogs and evaluation of acetylcholinesterase and carbonic anhydrase inhibition properties

Fused pyrimidines, especially pyrazolo[3,4-d]pyrimidines, are among the most preferred building blocks for pharmacology studies, as they exhibit a broad spectrum of biological activity. In this study, new derivatives of pyrazolo[3,4-d]pyrimidine were synthesized by alkylation of the N1 nitrogen atom. We synthesized 3-iodo-1H-pyrazolo[3,4-d]pyrimidin-4-amine 2 from commercially available aminopyrazolopyrimidine 1 using N-iodosuccinimide as an iodinating agent. The synthesis of compound 2 started with nucleophilic substitution of 3-iodo-1H-pyrazolo[3,4-d]pyrimidin-4-amine with R-X (X: -OMs, -Br, -Cl), affording N-alkylated pyrazolo[3,4-d]pyrimidine. We performed this synthesis using a weak inorganic base and the mild temperature was also used for a two-step procedure to generate N-alkylated pyrazolo[3,4-d]pyrimidine derivatives. Also, all compounds were tested for their ability to inhibit acetylcholinesterase (AChE) and the human carbonic anhydrase (hCA) isoforms I and II, with K_i values in the range of 15.41 ± 1.39-63.03 ± 10.68 nM for AChE, 17.68 ± 1.92-66.27 ± 5.43 nM for hCA I, and 8.41 ± 2.03-28.60 ± 7.32 nM for hCA II. Notably, compound 10 was the most selective and potent CA I inhibitor with a significant selectivity ratio of 26.90.