Synthesis of benzamide derivatives with thiourea-substituted benzenesulfonamides as carbonic anhydrase inhibitors

Carbonic anhydrases: Moiety appended derivatives, medicinal and pharmacological implications

In the realm of enzymology, Carbonic anhydrase (CA) emerges as a pivotal protagonist orchestrating the rapid conversion of carbon dioxide and water into bicarbonate ions and hydrogen ions, respectively. Carbonic anhydrase inhibitors (CAIs) are the class of drugs that target various isoforms of the enzyme, and these inhibitors play a crucial role in the treatment and management of multiple diseases such as cancer, glaucoma, high altitude sickness, rheumatoid arthritis, obesity, epilepsy, and sleep apnea. Several structural classes of CAIs developed till date possess unique architects of the pharmacophoric requirements around the central core moiety for the selective targeting of various isoforms of the CA. Recent advancements in drug design and development, along with technologies that aid in structure determination, have led to the development of several isoform-selective inhibitors of CA enzymes. However, their clinical development was hampered by the lack of desired therapeutic efficacy, isoform selectivity and safety profile. This review covers the most recent approaches used by different researchers concerned with the development of isoform-selective carbonic anhydrase inhibitors belonging to distinct structural classes like sulphonamides, carbazoles, selenols, coumarin, organotelluride, topiramate, thiophene, triazole, uracil-modified benzylic amines, and thiourea etc. In addition, their structure-activity relationships, biological evaluation, and in silico studies inlcuding the forthcoming avenues of advancements have been discussed. This review serves as a valuable resource for developing potent and efficacious CAIs with remarkable therapeutic implications; offering insights into their potency, specificity, and potential clinical applications.

Synthesis and biological studies of pyrimidine derivatives targeting metabolic enzymes

Novel synthesized pyrimidine derivatives were investigated against carbonic anhydrase isoenzymes I and II (hCA I and II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glycosidase, and aldose reductase (AR) enzymes associated with some common diseases such as epilepsy, glaucoma, Alzheimer's disease, diabetes, and neuropathy. When the results were examined, novel synthesized pyrimidine derivatives were found to have effective inhibition abilities toward the metabolic enzymes. IC50 values and Ki values were calculated for each pyrimidine derivative and compared to positive controls. The synthesized novel pyrimidine derivatives exhibited Ki values in the range of 39.16 ± 7.70-144.62 ± 26.98 nM against hCA I, 18.21 ± 3.66-136.35 ± 21.48 nM toward hCA II, which is associated with different pathological and physiological processes, 33.15 ± 4.85-52.98 ± 19.86 nM on AChE, and 31.96 ± 8.24-69.57 ± 21.27 nM on BChE. Also, Ki values were determined in the range of 17.37 ± 1.11-253.88 ± 39.91 nM against α-glycosidase and 648.82 ± 53.74-1902.58 ± 98.90 nM toward AR enzymes. Within the scope of the study, the inhibition types of the novel synthesized pyrimidine derivatives were evaluated.

The synthesis, carbonic anhydrase and acetylcholinesterase inhibition effects of sulfonyl chloride moiety containing oxazolidinones using an intramolecular aza-Michael addition

Oxazolidinones are used as various potent antibiotics, in organisms it acts as a protein synthesis inhibitor, focusing on an initial stage that encompasses the tRNA binding process. Novel intramolecular aza-Michael reactions devoid of metal catalysts have been introduced in an oxazolidone synthesis pathway, different from α,β-unsaturated ketones. Oxazolidinone derivatives were tested against acetylcholinesterase (AChE), carbonic anhydrase I and II (hCA I and hCA II) enzymes. All the synthesized compounds had potent inhibition effects with Ki values in the range of 13.57 ± 0.98 - 53.60 ± 6.81 µM against hCA I and 9.96 ± 1.02 - 46.35 ± 3.83 µM against hCA II in comparison to the acetazolamide (AZA) (Ki = 50.46 ± 6.17 µM for hCA I) and for hCA II (Ki = 41.31 ± 5.05 µM). Also, most of the compounds demonstrated potent inhibition ability towards AChE enzyme with Ki values 78.67-231.75 nM and compared to tacrine (TAC) as standard clinical inhibitor (Ki = 142.48 nM). Furthermore, ADMET analysis and molecular docking were calculated using the AChE, hCA I and hCA II enzyme proteins to correlate the data with the experimental data. In this work, recent applications of a stereoselective aza-Michael reaction as an efficient tool for of nitrogen-containing heterocyclic scaffolds and their useful to pharmacology analogs are reviewed and summarized.Communicated by Ramaswamy H. Sarma.

Benzimidazolium Salts Bearing Nitrile Moieties: Synthesis, Enzyme Inhibition Profiling, and Molecular Docking Analysis for Carbonic Anhydrase and Acetylcholinesterase

This report presents the synthesis and characterization of a range of benzimidazolium salts featuring 3-cyanopropyl groups on the 1st nitrogen atom and varied alkyl groups on the 3rd nitrogen atom within the benzimidazole structure. Benzimidazolium salts were synthesized by N-alkylation of 1-alkyl benzimidazole with 3-cyanopropyl-bromide. The new salts were characterized by 1 H and 13 C-NMR, FT-IR spectroscopic and elemental analysis techniques. In this study, the enzyme inhibition abilities of seven nitrile substituted benzimidazolium salts were investigated against acetylcholinesterase (AChE) and carbonic anhydrase isoenzymes I and II (hCA I and hCA II). They showed a highly potent inhibition effect on AChE, hCA I and hCA II (Ki values are in the range of 26.71-119.09 nM for AChE, 19.77 to 133.68 nM for hCA I and 13.09 to 266.38 nM for hCA II). Reflecting the binding mode of the synthesized cyanopropyl series, the importance of the 2,3,5,6-tetramethylbenzyl, 3-methylbenzyl and 3-benzyl groups for optimal interactions with target proteins, evaluated by molecular docking studies. At the same time, the docking findings support the inhibition constants (Ki ) values of the related compounds in this study. Potential compounds were also evaluated by their pharmacokinetic properties were predicted.

Inhibition Studies on Human and Mycobacterial Carbonic Anhydrases with N-((4-Sulfamoylphenyl)carbamothioyl) Amides

A library of structurally diverse N-((4-sulfamoylphenyl)carbamothioyl) amides was synthesized by selective acylation of easily accessible 4-thioureidobenzenesulfonamide with various aliphatic, benzylic, vinylic and aromatic acyl chlorides under mild conditions. Inhibition of three α-class cytosolic human (h) carbonic anhydrases (CAs) (EC 4.2.1.1); that is, hCA I, hCA II and hCA VII and three bacterial β-CAs from Mycobacterium tuberculosis (MtCA1-MtCA3) with these sulfonamides was thereafter investigated in vitro and in silico. Many of the evaluated compounds displayed better inhibition against hCA I (K_I = 13.3-87.6 nM), hCA II (K_I = 5.3-384.3 nM), and hCA VII (K_I = 1.1-13.5 nM) compared with acetazolamide (AAZ) as the control drug (K_I values of 250, 12.5 and 2.5 nM, respectively, against hCA I, hCA II and hCA VII). The mycobacterial enzymes MtCA1 and MtCA2 were also effectively inhibited by these compounds. MtCA3 was, on the other hand, poorly inhibited by the sulfonamides reported here. The most sensitive mycobacterial enzyme to these inhibitors was MtCA2 in which 10 of the 12 evaluated compounds showed K_Is (K_I, the inhibitor constant) in the low nanomolar range.

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.

Recombinant human carbonic anhydrase VII: Purification, characterization, inhibition, and molecular docking studies

Human carbonic anhydrase VII (hCA VII), a cytosolic enzyme, defends against oxidative stress by preventing reactive oxygen species from forming. In our study, first, hCA VII was cloned into Escherichia coli (One Shot Mach1-T1R) strain by using cDNA of the human brain and successfully expressed. The integrity of the plasmid generated by colony PCR was checked, and after, for protein expression, the plasmid was transformed into E. coli BL21 (DE-3) strain. hCA VII expression was observed after 6 h of isopropyl-D-1-thiogalactopyranoside (IPTG) induction. The fusion protein containing hexahistidine (6xHis) was purified with 7.02 EU/mg of specific activity, had 48.07% of purification yield, and approximately 21-folds using a ProbondTM nickel chelating resin affinity column. Then, both molecular mass determination and purity control of the purified recombinant enzyme was done by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). The mass of the SUMO-hCA VII fusion protein was calculated as 46.77 kDa. As a result of Western blot analysis using anti-His G-HRP antibody, the fusion protein was detected as approximately 45 kDa. Furthermore, the characterization assays and in vitro inhibition studies were done for the recombinant enzyme. K_I values of these agents were found between 0.29 μM and 157.6 mM. Finally, molecular docking investigations of these antibiotics were undertaken to understand further the binding interactions on the active site of this recombinant enzyme.

Molecular Docking Studies and the Effect of Fluorophenylthiourea Derivatives on Glutathione-Dependent Enzymes

Cancer is a serious problem affecting the health of all human societies. Chemotherapy refers to the use of drugs to kill cancer or the origin of cancer. In the past three decades, researchers have studied about proteins and their roles in the production of cancer cells. Glutathione S-transferases (GSTs) are a superfamily of enzymes that play a key role in cellular detoxification, protecting against reactive electrophiles attacks, including chemotherapeutic agents. Glutathione reductase (GR) is an important antioxidant enzyme involved in protecting the cell against oxidative stress. In this current study, GST and GR enzymes were purified from human erythrocytes using affinity chromatography. GR was obtained with a specific activity of 5.95 EU/mg protein and a 52.38 % yield. GST was obtained with a specific activity of 4.88 EU/mg protein and a 74.88 % yield. The effect of fluorophenylthiourea derivatives on the purified enzymes was investigated. Afterward, K_I values were found to range from 23.04±4.37 μM-59.97±13.45 μM for GR and 7.22±1.64 μM-41.24±2.55 μM for GST. 1-(2,6-difluorophenyl)thiourea was showed the best inhibition effect for both GST and GR enzymes. The relationships of inhibitors with 3D structures of GST and GR were explained by molecular docking studies.

Enzyme inhibition, molecular docking, and density functional theory studies of new thiosemicarbazones incorporating the 4-hydroxy-3,5-dimethoxy benzaldehyde motif

New Schiff base-bearing thiosemicarbazones (1-13) were obtained from 4-hydroxy-3,5-dimethoxy benzaldehyde and various isocyanates. The structures of the synthesized molecules were elucidated in detail. Density functional theory calculations were also performed to determine the spectroscopic properties of the compounds. Moreover, the enzyme inhibition activities of these compounds were investigated. They showed highly potent inhibition effects on acetylcholinesterase (AChE) and human carbonic anhydrases (hCAs) (K_I values are in the range of 51.11 ± 6.01 to 278.10 ± 40.55 nM, 60.32 ± 9.78 to 300.00 ± 77.41 nM, and 64.21 ± 9.99 to 307.70 ± 61.35 nM for AChE, hCA I, and hCA II, respectively). In addition, molecular docking studies were performed, confirmed by binding affinities studies of the most potent derivatives.

Screening of in vitro and in silico effect of Fluorophenylthiourea compounds on glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase enzymes

Inhibition studies of enzymes in the pentose phosphate pathway (PPP) have recently emerged as a promising technique for pharmacological intervention in several illnesses. Glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) are the most important enzymes of the PPP. For this purpose, in the current study, we examined the effect of some fluorophenylthiourea on G6PD and 6PGD enzyme activity. These compounds exhibited moderate inhibitory activity against G6PD and 6PGD with K_I values ranging from 21.60 ± 8.42 to 39.70 ± 11.26 μM, and 15.82 ± 1.54 to 29.97 ± 5.72 μM, respectively. 2,6-difluorophenylthiourea displayed the most potent inhibitory effect for G6PD, and 2-fluorophenylthiourea demonstrated the most substantial inhibitory effect for 6PGD. Furthermore, the molecular docking analyses of the fluorophenylthioureas, competitive inhibitors, were performed to understand the binding interactions at the enzymes' binding site.

Synthesis of Novel Bromophenol with Diaryl Methanes—Determination of Their Inhibition Effects on Carbonic Anhydrase and Acetylcholinesterase

In this work, nine new bromophenol derivatives were designed and synthesized. The alkylation reactions of (2-bromo-4,5-dimethoxyphenyl)methanol (7) with substituted benzenes 8–12 produced new diaryl methanes 13–17. Targeted bromophenol derivatives 18–21 were synthesized via the O-Me demethylation of diaryl methanes with BBr3. Moreover, the synthesized bromophenol compounds were tested with some metabolic enzymes such as acetylcholinesterase (AChE), carbonic anhydrase I (CA I), and II (CA II) isoenzymes. The novel synthesized bromophenol compounds showed Ki values that ranged from 2.53 ± 0.25 to 25.67 ± 4.58 nM against hCA I, from 1.63 ± 0.11 to 15.05 ± 1.07 nM against hCA II, and from 6.54 ± 1.03 to 24.86 ± 5.30 nM against AChE. The studied compounds in this work exhibited effective hCA isoenzyme and AChE enzyme inhibition effects. The results show that they can be used for the treatment of glaucoma, epilepsy, Parkinson’s as well as Alzheimer’s disease (AD) after some imperative pharmacological studies that would reveal their drug potential.

Discovery of novel drugs for Chagas disease: is carbonic anhydrase a target for antiprotozoal drugs?

INTRODUCTION

Carbonic anhydrase (CA) arose significant interest as a potential new target for Chagas disease since its discovery in Trypanosoma cruzi in 2013. Benznidazole and Nifurtimox have been used for Chagas disease treatment for 60 years despite all efforts done for obtaining more efficient treatments, acting in the acute and chronic phases of illness, with fewer side effects and resistance induction.

AREAS COVERED

We discuss the positive and negative aspects of T. cruzi CA (TcCA) studies as a target for developing new drugs. The current research discoveries and the classes of TcCA inhibitors are reviewed. The sulfonamides and their derivatives are the main inhibitor classes, but hydroxamates and the thiols, were investigated too. These compounds inhibited the growth of the evolutive forms of the parasite. A comparative analysis was done with CAs from other Trypanosomatids and protozoans.

EXPERT OPINION

The search for new targets and drugs is a significant challenge worldwide, and TcCA is a potential candidate for developing new drugs. Several studied inhibitors were active against Trypanosoma cruzi, but their penetration and toxicity problems emerged. New approaches are in progress to obtain inhibitors with desired properties, allowing further steps such as tests using an adequate animal model and subsequent developments for the preclinical testing.

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.

Discovery of new anticancer thiourea-azetidine hybrids: design, synthesis, in vitro antiproliferative, SAR, in silico molecular docking against VEGFR-2, ADMET, toxicity, and DFT studies

With the aim to discover potent and novel antitumor agents, a series of thiourea compounds bearing 3-(4-methoxyphenyl)azetidine moiety were designed according to the essential pharmacophoric features of the reported VEGFR-2 inhibitors and synthesized. All the synthesized compounds were evaluated for their in vitro anticancer activity against various human cancer cell lines (lung (A549), prostate (PC3), breast (MCF-7), liver (HepG2), colon (HCT-116), ovarian (SKOV-3), skin (A431), brain (U251) and kidney (786-O)). 3-(4-Methoxy-3-(2-methoxypyridin-4-yl)phenyl)-N-(4-methoxyphenyl)azetidine-1-carbothioamide (3B) was found to be most potent member against PC3, U251, A431, and 786-O cancer cell lines with EC₅₀ values 0.25, 0.6, 0.03, and 0.03 µM, respectively and showed more potency than Doxorubicin in PC3, A431, and 786-O cell lines. Compounds 1B to 7B showed EC₅₀ values ranging from 0.03 to 12.55 µM in A431 cell line. Compound 3-(4-methoxy-3-(pyridin-4-yl)phenyl)-N-(4-methoxyphenyl)azetidine-1-carbothioamide (1B) was found to be highly efficient in A431 and 786-O cell line with EC₅₀ values of 0.77 and 0.73 µM respectively. All the compounds exhibited good to moderate cytotoxic activity. The pharmacophoric features and molecular docking studies confirmed the potentialities of compounds 1B, 2B, 3B and 5B to be VEGFR-2 inhibitors. Moreover, in silico ADMET prediction indicated that most of the synthesized compounds have drug-like properties, possess low adverse effects and toxicity. In addition, the DFT studies for the most active compounds (1B and 3B) were carried out. In the end, our studies revealed that the compounds 1B and 3B represent promising anticancer potentialities through their VEGFR-2 inhibition.

Novel inhibitors with sulfamethazine backbone: synthesis and biological study of multi-target cholinesterases and α-glucosidase inhibitors

The underlying cause of many metabolic diseases is abnormal changes in enzyme activity in metabolism. Inhibition of metabolic enzymes such as cholinesterases (ChEs; acetylcholinesterase, AChE and butyrylcholinesterase, BChE) and α-glucosidase (α-GLY) is one of the accepted approaches in the treatment of Alzheimer's disease (AD) and diabetes mellitus (DM). Here we reported an investigation of a new series of novel ureido-substituted derivatives with sulfamethazine backbone (2a-f) for the inhibition of AChE, BChE, and α-GLY. All the derivatives demonstrated activity in nanomolar levels as AChE, BChE, and α-GLY inhibitors with K_I values in the range of 56.07-204.95 nM, 38.05-147.04 nM, and 12.80-79.22 nM, respectively. Among the many strong N-(4,6-dimethylpyrimidin-2-yl)-4-(3-substitutedphenylureido) benzenesulfonamide derivatives (2a-f) detected against ChEs, compound 2c, the 4-fluorophenylureido derivative, demonstrated the most potent inhibition profile towards AChE and BChE. A comprehensive ligand/receptor interaction prediction was performed in silico for the three metabolic enzymes providing molecular docking investigation using Glide XP, MM-GBSA, and ADME-Tox modules. The present research reinforces the rationale behind utilizing inhibitors with sulfamethazine backbone as innovative anticholinergic and antidiabetic agents with a new mechanism of action, submitting propositions for the rational design and synthesis of novel strong inhibitors targeting ChEs and α-GLY.Communicated by Ramaswamy H. Sarma.