Design, synthesis, and molecular docking studies of benzimidazole-1,3,4-triazole hybrids as carbonic anhydrase I and II inhibitors.

In this study, with an aim to develop novel heterocyclic hybrids as potent enzyme inhibitors, we synthesized a series of 10 novel 2-(4-(4-ethyl-5-(2-(substitutedphenyl)-2-oxo-ethylthio)-4H-1,2,4-triazol-3-yl)-phenyl)-5,6-dimethyl-1H-benzimidazole (5a-5j) derivatives and characterized by 1 H-NMR, 13 C-NMR, and HRMS. These compounds were evaluated for their inhibitory activity against hCA I and hCA II. All the compounds exhibited good hCA I and hCA II inhibitory activities with IC50 values in range of 1.288 µM-3.122 µM. Among all these compounds, compound 5e, with an IC50 value of 1.288 µM is the most active against carbonic hCA I. Compound 5h with an IC50 value of 1.532 µM is the most active against carbonic hCA-II. Compounds 5a-5j were also evaluated for their cytotoxic effects on the L929 mouse fibroblast (normal) cell line. The compounds were also analyzed for their antioxidant capacity by TAS, FRAP, and DPPH activity. Enzyme inhibition kinetics showed all compounds 5a-5j to inhibit the enzyme by non-competitive. The most active compound 5e for hCA I and compound 5h for hCA-II were subjected to molecular docking, which revealed their binding interactions with the enzyme's active site, confirming the experimental findings.

Synthesis and Molecular Docking of New N-Acyl Hydrazones- Benzimidazole as hCA I and II Inhibitors.

BACKGROUND: The carbonic anhydrases (CAs) which are found in most living organisms is a member of the zinc-containing metalloenzyme family. The abnormal levels and activities are frequently associated with various diseases therefore CAs have become an attractive target for the design of inhibitors or activators that can be used in the treatment of those diseases. METHODS: Herein, we have designed and synthesized new benzimidazole-hydrazone derivatives to investigate the effects of these synthesized compounds on CA isoenzymes. Chemical structures of synthesized compounds were confirmed by 1H NMR, 13C NMR, and HRMS. The synthetic derivatives were screened for their inhibitory potential against carbonic anhydrase I and II by in vitro assay. RESULTS: These compounds have IC50 values of 5.156-1.684 µM (hCA I) and 4.334-2.188 µM (hCA II). Inhibition types and Ki values of the compounds were determined. The Ki values of the compounds were 5.44 ± 0.14 µM-0.299 ± 0.01 µM (hCA I) and 3.699 ± 0.041 µM-1.507 ± 0.01 µM (hCA II). The synthetic compounds displayed inhibitory action comparable to that of the clinically utilized reference substance, acetazolamide. According to this, compound 3p was the most effective molecule with an IC50 value of 1.684 µM. Accordingly, the type of inhibition was noncompetitive and the Ki value was 0.299 ± 0.01 µM. CONCLUSION: According to the in vitro test results, detailed protein-ligand interactions of the compound 3p, which is more active against hCA I than standard azithromycin (AZM), were analyzed. In addition, the cytotoxic effects of the compounds on the L929 healthy cell line were evaluated.

What are the drugs having potential against COVID-19?

A disease emerged in the city of Wuhan, Hubei Province, Central China in the last month of 2019. It was pneumonia caused by a newly emerged coronavirus called COVID-19, later. Coronaviruses are enveloped RNA viruses belong to the Betacoronavirus family and infected birds, humans, and other mammals. In March 2020, the World Health Organization declared the COVID-19 outbreak could be characterized as a global pandemic because the disease spread, and a large number of people were infected and died in many countries on different continents by virtue of this new virus. Now, intensive work is underway about the pathogenic mechanisms and epidemiological properties of COVID-19, and a great effort is made to develop effective specific therapeutic drugs, vaccines, and/or treatment strategies against these diseases. Herein, we have focused on all treatment options available against COVID-19 pneumonia in this text.

Investigation of inhibitory properties of some hydrazone compounds on hCA I, hCA II and AChE enzymes.

Recently, inhibition of carbonic anhydrase (hCA) and acetylcholinesterase (AChE) have appeared as a promising approach for pharmacological intervention in a variety of disorders such as glaucoma, epilepsy, obesity, cancer, and Alzheimer's disease. Keeping this in mind, N,N'-bis[(1-aryl-3-heteroaryl)propylidene]hydrazine dihydrochlorides, N1-N11, P1, P4-P8, and R1-R6, were synthesized to investigate their inhibitory activity against hCA I, hCA II, and AChE enzymes. All compounds in N, P, and R-series inhibited hCAs (I and II) and AChE more efficiently than the reference compounds acetazolamide (AZA), and tacrine. According to the activity results, the most effective inhibitory compounds were in R-series with the Ki values of 203 ±â€¯55-473 ±â€¯67 nM and 200 ±â€¯34-419 ±â€¯94 nM on hCA I, and hCA II, respectively. N,N'-Bis[1-(4-fluorophenyl)-3-(morpholine-4-yl)propylidene]hydrazine dihydrochlorides, N8, in N-series, N,N'-Bis[1-(4-hydroxyphenyl)-3-(piperidine-1-yl)propylidene]hydrazine dihydrochlorides, P4, in P-series, and N,N'-bis[1-(4-chlorophenyl)-3-(pyrrolidine-1-yl)propylidene]hydrazine dihydrochlorides, R5, in R-series were the most powerful compounds against hCA I with the Ki values of 438 ±â€¯65 nM, 344 ±â€¯64 nM, and 203 ±â€¯55 nM, respectively. Similarly, N8, P4, and R5 efficiently inhibited hCA II isoenzyme with the Ki values of 405 ±â€¯60 nM, 327 ±â€¯80 nM, and 200 ±â€¯34 nM, respectively. On the other hand, P-series compounds had notable inhibitory effect against AChE than the reference compound tacrine and the Ki values were between 66 ±â€¯20 nM and 128 ±â€¯36 nM. N,N'-Bis[1-(4-fluorophenyl)-3-(piperidine-1-yl)propylidene]hydrazine dihydrochlorides, P7, was the most potent compound on AChE with the Ki value of 66 ±â€¯20 nM. The other most promising compounds, N,N'-bis[1-(4-hydroxyphenyl)-3-(morpholine-4-yl)propylidene]hydrazine dihydrochlorides, N4 in N-series and N,N'-bis[1-(4-hydroxyphenyl)-3-(pyrrolidine-1-yl)propylidene]hydrazine dihydrochlorides, R4 in R-series were againts AChE with the Ki values of 119 ±â€¯20 nM, 88 ±â€¯14 nM, respectively.

In silico Molecular Docking and ADME Studies of 1,3,4-Thiadiazole Derivatives in Relation to in vitro PON1 Activity.

BACKGROUND: Paraoxonase 1 (PON1) is a paraoxonase, arylesterase and lactonase associated with protection of lipoproteins and cell membranes against oxidative modification. OBJECTIVE: Based on antioxidative properties of PON1 and significance of 1,3,4-thiadiazoles in pharmaceutical chemistry, herein we aimed to evaluate the potentials of 1,3,4-thiadiazole derivatives as PON1 activators. METHODS: 2-[[5-(2,4-Difluoro/dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio]acetophenone derivatives (1-18) were in vitro evaluated for their activator effects on PON1 which was purified using ammonium sulfate precipitation (60-80%) and DEAE-Sephadex anion exchange chromatography. Molecular docking studies were performed for the detection of affinities of all compounds to the active site of PON1. Moreover, Absorption, Distribution, Metabolism and Excretion (ADME) properties of all compounds were also in silico predicted. In silico molecular docking and ADME studies were carried out according to modules of Schrodinger's Maestro molecular modeling package. RESULTS: All compounds, particularly compounds 10, 13 and 17, were determined as promising PON1 activators and apart from compound 1, all of them were detected in the active site of PON1. Besides, ADME results indicated that all compounds were potential orally bioavailable drug-like molecules. CONCLUSION: PON1 activators, compounds 10, 13 and 17 stand out as potential drug candidates for further antioxidant studies and these compounds can be investigated for their therapeutic effects in many disorders such as atherosclerosis, diabetes mellitus, obesity, chronic liver inflammation and many more.

Potential inhibitors of human carbonic anhydrase isozymes I and II: Design, synthesis and docking studies of new 1,3,4-thiadiazole derivatives.

In the last years, inhibition of carbonic anhydrase (CA) has emerged as a promising approach for pharmacologic intervention in a variety of disorders such as glaucoma, epilepsy, obesity, and cancer. As a consequence, the design of CA inhibitors (CAIs) is a highly dynamic field of medicinal chemistry. Due to the therapeutic potential of thiadiazoles as CAIs, new 1,3,4-thiadiazole derivatives were synthesized and investigated for their inhibitory effects on hCA I and hCA II. Although the tested compounds did not carry a sulfonamide group, an important pharmacophore for CA inhibitory activity, it was a remarkable finding that most of them were more effective on hCAs than acetazolamide (AAZ), the reference agent. Among these compounds, N'-((5-(4-chlorophenyl)furan-2-yl)methylene)-2-((5-(phenylamino)-1,3,4-thiadiazol-2-yl)thio)acetohydrazide (3) was found to be the most effective compound on hCA I with an IC50 value of 0.14nM, whereas N'-((5-(2-chlorophenyl)furan-2-yl)methylene)-2-((5-(phenylamino)-1,3,4-thiadiazol-2-yl)thio)acetohydrazide (1) was found to be the most potent compound on hCA II with an IC50 value of 0.15nM. According to molecular docking studies, all compounds exhibited high affinity and good amino acid interactions similar to AAZ on the both active sites of hCA I and hCA II enzymes.

Microwave-assisted synthesis and bioevaluation of new sulfonamides.

In this study, 4-[5-(4-hydroxyphenyl)-3-aryl-4,5-dihydro-1H-pyrazol-1-yl]benzenesulfonamide derivatives (8-14) were synthesized for the first time by microwave irradiation and their chemical structures were confirmed by 1H NMR, 13C NMR and HRMS. Cytotoxic activities and inhibitory effects on carbonic anhydrase I and II isoenzymes of the compounds were investigated. The compounds 9 (PSE = 4.2), 12 (PSE = 4.1) and 13 (PSE = 3.9) with the highest potency selectivity expression (PSE) values in cytotoxicity experiments and the compounds 13 (Ki = 3.73 ± 0.91 nM toward hCA I) and 14 (Ki = 3.85 ± 0.57 nM toward hCA II) with the lowest Ki values in CA inhibition studies can be considered as leader compounds for further studies.

Synthesis and evaluation of new benzodioxole-based dithiocarbamate derivatives as potential anticancer agents and hCA-I and hCA-II inhibitors.

In the current work, new benzodioxole-based dithiocarbamate derivatives were synthesized via the reaction of N-(1,3-benzodioxol-5-ylmethyl)-2-chloroacetamide with appropriate sodium salts of N,N-disubstituted dithiocarbamic acids. These derivatives were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and C6 rat glioma cell lines. N-(1,3-Benzodioxol-5-ylmethyl)-2-[4-(4-nitrophenyl)-1-piperazinylthiocarbamoylthio]acetamide (10) can be identified as the most promising anticancer agent against C6 cell line due to its notable inhibitory effect on C6 cells with an IC50 value of 23.33 ± 7.63 µg/mL when compared with cisplatin (IC50 = 19.00 ± 5.29 µg/mL). On the other hand, compound 10 did not show any significant cytotoxic activity against A549 cell line. The compounds were also tested for their in vitro inhibitory effects on hCA-I and hCA-II. Generally, the tested compounds were more effective on CAs than acetazolamide, the reference agent. Among these compounds, N-(1,3-benzodioxol-5-ylmethyl)-2-[(morpholinyl)thiocarbamoylthio]acetamide (3) and N-(1,3-benzodioxol-5-ylmethyl)-2-[(thiomorpholinyl)thiocarbamoylthio]acetamide (4) were found to be the most effective compounds on hCA-I with IC50 values of 0.346 nM and 0.288 nM, and hCA-II with IC50 values of 0.287 nM and 0.338 nM, respectively.

Synthesis, cytotoxicity and carbonic anhydrase inhibitory activities of new pyrazolines.

A series of polymethoxylated-pyrazoline benzene sulfonamides were synthesized, investigated for their cytotoxic activities on tumor and non-tumor cell lines and inhibitory effects on carbonic anhydrase isoenzymes (hCA I and hCA II). Although tumor selectivity (TS) of the compounds were less than the reference compounds 5-Fluorouracil and Melphalan, trimethoxy derivatives 4, 5, and 6 were more selective than dimethoxy derivatives 2 and 3 as judged by the cytotoxicity assay with the cells both types originated from the gingival tissue. The compound 6 (4-[3-(4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl] benzene sulfonamide) showed the highest TS values and can be considered as a lead molecule of the series for further investigations. All compounds synthesized showed superior CA inhibitory activity than the reference compound acetazolamide on hCA I, and II isoenzymes, with inhibition constants in the range of 26.5-55.5 nM against hCA I and of 18.9-28.8 nM against hCA II, respectively.

Simple high-performance liquid chromatography method for formaldehyde determination in human tissue through derivatization with 2,4-dinitrophenylhydrazine.

A simple high-performance liquid chromatography method has been developed for the determination of formaldehyde in human tissue. FA Formaldehyde was derivatized with 2,4-dinitrophenylhydrazine. It was extracted from human tissue with ethyl acetate by liquid-liquid extraction and analyzed by high-performance liquid chromatography. The calibration curve was linear in the concentration range of 5.0-200 µg/mL. Intra- and interday precision values for formaldehyde in tissue were <6.9%, and accuracy (relative error) was better than 6.5%. The extraction recoveries of formaldehyde from human tissue were between 88 and 98%. The limits of detection and quantification of formaldehyde were 1.5 and 5.0 µg/mL, respectively. Also, this assay was applied to liver samples taken from a biopsy material.

Synthesis of 4-(2-substituted hydrazinyl)benzenesulfonamides and their carbonic anhydrase inhibitory effects.

In this study, 4-(2-substituted hydrazinyl)benzenesulfonamides were synthesized by microwave irradiation and their chemical structures were confirmed by (1)H NMR, (13)CNMR, and HRMS. Ketones used were: Acetophenone (S1), 4-methylacetophenone (S2), 4-chloroacetophenone (S3), 4-fluoroacetophenone (S4), 4-bromoacetophenone (S5), 4-methoxyacetophenone (S6), 4-nitroacetophenone (S7), 2-acetylthiophene (S8), 2-acetylfuran (S9), 1-indanone (S10), 2-indanone (S11). The compounds S9, S10 and S11 were reported for the first time, while S1-S8 was synthesized by different method than literature reported using microwave irradiation method instead of conventional heating in this study. The inhibitory effects of 4-(2-substituted hydrazinyl)benzenesulfonamide derivatives (S1-S11) against hCA I and II were studied. Cytosolic hCA I and II isoenzymes were potently inhibited by new synthesized sulphonamide derivatives with Kis in the range of 1.79 ± 0.22-2.73 ± 0.08 nM against hCA I and in the range of 1.72 ± 0.58-11.64 ± 5.21 nM against hCA II, respectively.

Synthesis of 3-aroyl-4-aryl-1-isopropylamino-4-piperidinols and evaluation of the cytotoxicities of the compounds against human hepatoma and breast cancer cell lines.

Some 4-piperidinol derivatives were synthesized and their cytotoxicity was tested against human hepatoma (Huh7) and breast cancer (T47D) cells. Aryl part was changed as phenyl in 2a, 4-methylphenyl in 2b, 4-methoxyphenyl in 2c, 4-chlorophenyl in 2d, 4-fluorophenyl in 2e, 4-bromophenyl in 2f, 4-nitrophenyl in 2g and 2-thienyl in 3. Compounds were synthesized and reported for the first time by this study except 2a and 2d. Chemical structures were confirmed by (1)H NMR, (13)C NMR, IR, MS and elemental analyses. Compounds 2a (3.1 times), 2c (3.8 times), 2f (4.6 times), 2g (1.3 times) and 3 (3.2 times) had 1.3-4.6 times higher cytotoxic potency than the reference compound 5-FU against Huh7 cell line while all the compounds synthesized had shown lower activities against T47D cell line than 5-FU. In the light of these results, compounds 2a, 2c, 2f, 2g and 3 may serve as model compounds for further studies.

Synthesis and evaluation of new thiadiazole derivatives as potential inhibitors of human carbonic anhydrase isozymes (hCA-I and hCA-II).

2-[[5-(2,4-Difluoro/dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio] acetophenone derivatives (3a--s) were designed as human carbonic anhydrase isozymes (hCA-I and hCA-II) inhibitors and synthesized. hCA-I and hCA-II were purified from erythrocyte cells by the affinity chromatography. The inhibitory effects of 18 newly synthesized acetophenones on hydratase activity of these isoenzymes were studied in vitro. The average IC50 values of the new compounds for hydratase activity ranged from 0.033 to 0.14 µM for hCA-I and from 0.030 to 0.11 µM for hCA-II. Among the newly synthesized compounds, 2-[[5-(2,4-dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio]-4'-bromoacetophenone (3n) can be considered as a promising hCA-II inhibitor owing to its selective and potent inhibitory effect on hCA-II.

Synthesis of new N,N'-bis[1-aryl-3-(piperidine-1-yl)propylidene]hydrazine dihydrochlorides and evaluation of their cytotoxicity against human hepatoma and breast cancer cells.

N,N'-Bis[1-aryl-3-(piperidine-1-yl)propylidene]hydrazine dihydrochlorides were synthesized by the reaction of 2 mols of 1-aryl-3-(piperidine-1-yl)-1-propanone hydrochlorides with 1 mol of hydrazine hydrate. Aryl part was C6H5 (P1), 4-CH3C6H4 (P2), 4-CH3OC6H4 (P3), 4-HOC6H4 (P4), 4-ClC6H4 (P5), 3-CH3OC6H4 (P6), 4-FC6H4 (P7) and 4-BrC6H4 (P8). Except P1, all compounds were reported for the first time. The chemical structures were confirmed by UV, (1)H NMR, (13)C NMR and HRMS spectra. P1, P2, P7 and P8 against human hepatoma (Huh7) cells and P1, P2, P4, P5, P6, P7 and P8 against breast cancer (T47D) cells have shown cytotoxicity. P1, P2 and P7 had more potent cytotoxicity against Huh7 cells than the reference compound 5-FU, whereas only P2 was more potent than the 5-FU against T47D cells. Representative compound P7 inhibited the mitochondrial respiration at 144, 264 and 424 µM concentrations dose-dependantly in liver homogenates. The results suggest that P1, P2, P7 and P8 may serve as model compounds for further synthetic studies.

Synthesis of some Mannich bases with dimethylamine and their hydrazones and evaluation of their cytotoxicity against Jurkat cells.

1-Aryl-3-dimethylamino-1-propanone hydrochlorides type mono Mannich bases, D series, and corresponding hydrazone derivatives, K series, were synthesized and their cytotoxicity was tested against Jurkat cells (transformed human T-lymphocytes). The aryl part was changed as phenyl in D1 and K1, 4-methylphenyl in D2 and K2, 4-methoxyphenyl in D3 and K3, 4-hydroxyphenyl in D4 and K4, 4-chlorophenyl in D5 and K5, 3-methoxyphenyl in D6 and K6, 4-fluorophenyl in D7 and K7, 4-bromophenyl in D8 and K8, 3-hydroxyphenyl in D9 and K9, and 2-acetylthiophene in D10 and K10. Of the compounds synthesized, K2, K3, K5, K6, K7, K8, K9, and K10 are reported for the first time. Cytotoxic activities of the D and K series were compared with each other to see alterations in bioactivity depending on the chemical structures in Jurkat cells. Cytotoxicities of the compounds synthesized were also compared with the reference compound, 5-fluorouracil (CAS 148-82-3). Mono Mannich bases, D1 (3.60 times), D2 (4.45 times), D3 (2.46 times), D4 (3.52 times), D5 (5.18 times), D6 (3.20 times), D7 (3.23 times), D8 (3.95 times), D9 (3.36 times) and D10 (3.99 times) had 2.46-5.18 times higher cytotoxic potency than the reference compound 5-fluorouracil against Jurkat cells, while hydrazones K1 (4.92 times), K2 (4.65 times), K3 (6.04 times), K4 (6.34 times), K5 (4.67 times), K6 (5.12 times), K7 (5.39 times), K8 (8.31 times), K9 (4.65 times) and K10 (8.65 times) had 4.65-8.65 times higher cytotoxic potency than the reference compound 5-fluorouracil against the same cell line. On the other hand, hydrazone compounds K1 (1.37 times), K3 (2.46 times), K4 (1.80 times), K6 (1.60 times), K7 (1.67 times), K8 (2.11 times), K9 (1.38 times), and K10 (2.17 times) had 1.37-2.46 times higher cytotoxic potency than their corresponding mono Mannich bases. The results of this study suggest that hydrazones were better compounds compared with the corresponding mono Mannich bases in terms of cytotoxicity, and they may serve as model compounds to develop new cytotoxic agents for further studies.

Effect of some bis Mannich bases and corresponding piperidinols on DNA topoisomerase I.

Some acetophenone (CAS 98-86-2) derived bis Mannich bases, bis-(3-aryl-3-oxo-propyl)-methylamine hydrochlorides (B1-B5) and representative piperidinols, 4-aryl-3-arylcarbonyl-1-methyl-4-piperidinol hydrochlorides (C1, C2 and C5), which are the structural isomers of B1, B2 and B5, were synthesized and their effects on DNA topoisomerase I were tested. Aryl part was phenyl in B1 and C1, p-methylphenyl in B2 and C2, p-methoxyphenyl in B3, p-chlorophenyl in B4, and 2-thienyl in B5 and C5. The compounds' chemical structures were confirmed by UV, IR, 1H NMR, 13C NMR, ESI-MS spectra. The purity levels of the compounds were determined by elemental analysis. Among the compounds, B1-B5 and C5 were found to inhibit DNA topo isomerase I at varying degrees. The compounds B1-B5 and C5 manifested an average of 46%, 20%, 40%, 22%, 24% and 22% inhibition on topoisomerase I, respectively, suggesting that the cytotoxic actions of the compounds may be linked to DNA topoisomerase I inhibition. There was a significant negative correlation between the LC50 values reported and topoisomerase I inhibition among the compounds studied. The topoisomerase inhibiting effects of the compounds of the B series may be attributed to the linear structures of the compounds and the possible formation of the hydrogen bonds with the DNA nucleotides. Among the compounds studied, the most potent topoisomerase I inhibiting compounds B1 (46%) and B3 (40%) may serve as model compounds to develop new more potent topoisomerase inhibitors in future studies.