Synthesis, molecular docking and molecular dynamics simulations, drug-likeness studies, ADMET prediction and biological evaluation of novel pyrazole-carboxamides bearing sulfonamide moiety as potent carbonic anhydrase inhibitors.

Pyrazoles are unique bioactive molecules with a versatile biological profile and they have gained an important place on pharmaceutical chemistry. Pyrazole compounds containing sulfonamide nuclei also attract attention as carbonic anhydrase (CA) inhibitors. In this study, a library of pyrazole-carboxamides were synthesized and the structures of the synthesized molecules were characterized using FT-IR, 1H-NMR, 13C-NMR and HRMS. Then the inhibition effects of newly synthesized molecules on human erythrocyte hCA I and hCA II isoenzymes were investigated. Ki values of the compounds were in the range of 0.063-3.368 µM for hCA I and 0.007-4.235 µM for hCA II. Molecular docking studies were performed between the most active compounds 6a, 6b and the reference inhibitor, acetazolamide (AAZ) and the hCA I and hCA II receptors to investigate the binding mechanisms between the compounds and the receptors. These compounds showed better interactions than the AAZ. ADMET analyzes were performed for the compounds and it was seen that the compounds did not show AMES toxicity. The stability of the molecular docking results over time was analysed by 50 ns molecular dynamics simulations. Molecular dynamics simulations revealed that 6a and 6b exhibited good stability after docking to the binding sites of hCA I and hCA II receptors, with minor conformational changes and fluctuations.

Synthesis, molecular docking analysis, drug-likeness evaluation, and inhibition potency of new pyrazole-3,4-dicarboxamides incorporating sulfonamide moiety as carbonic anhydrase inhibitors.

A series of novel pyrazole-dicarboxamides were synthesized from pyrazole-3,4-dicarboxylic acid chloride and various primary and secondary sulfonamides. The structures of the new compounds were confirmed by FT-IR, 1H-NMR, 13C-NMR, and HRMS. Then the inhibition effects of newly synthesized molecules on human erythrocyte hCA I and hCA II isoenzymes were investigated. Ki values of the compounds were in the range of 0.024-0.496 µM for hCA I and 0.006-5.441 µM for hCA II. Compounds 7a and 7i showed nanomolar level of inhibition of hCA II, and these compounds exhibited high selectivity for this isoenzyme. Molecular docking studies were performed between the most active compounds 7a, 7b, 7i, and the reference inhibitor AAZ and the hCAI and hCAII to investigate the binding mechanisms between the compounds and the isozymes. These compounds showed better interactions than the AAZ. ADMET and drug-likeness analyses for the compounds have shown that the compounds can be used pharmacologically in living organisms.

Synthesis, characterization and in vitro inhibition of metal complexes of pyrazole based sulfonamide on human erythrocyte carbonic anhydrase isozymes I and II.

Sulfonamides represent an important class of biologically active compounds. A sulfonamide possessing carbonic anhydrase (CA) inhibitory properties obtained from a pyrazole based sulfonamide, ethyl 1-(3-nitrophenyl)-5-phenyl-3-((5-sulfamoyl-1,3,4-thiadiazol-2-yl)carbamoyl)-1H-pyrazole-4-carboxylate (1), and its metal complexes with the Ni(II) for (2), Cu(II) for (3) and Zn(II) for (4) have been synthesized. The structures of metal complexes (2-4) were established on the basis of their elemental analysis, 1H NMR, IR, UV-Vis and MS spectral data. The inhibition of two human carbonic anhydrase (hCA, EC 4.2.1.1) isoenzymes I and II, with 1 and synthesized complexes (2-4) and acetazolamide (AAZ) as a control compound was investigated in vitro by using the hydratase and esterase assays. The complexes 2, 3 and 4 showed inhibition constant in the range 0.1460-0.3930 µM for hCA-I and 0.0740-0.0980 µM for hCA-II, and they had effective more inhibitory activity on hCA-I and hCA-II than corresponding free ligand 1 and than AAZ.

The synthesis of novel pyrazole-3,4-dicarboxamides bearing 5-amino-1,3,4-thiadiazole-2-sulfonamide moiety with effective inhibitory activity against the isoforms of human cytosolic carbonic anhydrase I and II.

A series of 1-(3-substituted-phenyl)-5-phenyl-N(3),N(4)-bis(5-sulfamoyl-1,3,4-thiadiazol-2-yl)-1H-pyrazole-3,4-dicarboxamides (4-15) were synthesized. The structures of these pyrazole-sulfonamides were confirmed by FT-IR, (1)H NMR, (13)C NMR and elemental analysis methods. Human cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isozymes (hCA I and II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of newly synthesized derivatives (4-15) were investigated in vitro on esterase activities of these isozymes. The Ki values were determined as 0.119-3.999µM for hCA I and 0.084-0.878µM for hCA II. The results showed that the compound 6 for hCA I and the compound 11 for hCA II had the highest inhibitory effect. Beside that, the compound 8 had the lowest inhibition effect on both isozymes.

Synthesis, structure-activity relationships, and in vitro antibacterial and antifungal activity evaluations of novel pyrazole carboxylic and dicarboxylic acid derivatives.

A series of pyrazole-3-carboxylic acid and pyrazole-3,4-dicarboxylic acid derivatives were synthesized, the structures were confirmed by their NMR ((1)H and (13)C) and FT-IR spectra, and elemental analyses. The antibacterial and antifungal activities of the compounds against five bacterial and five fungal pathogens were screened using modified agar well diffusion assay. Most of the molecules have inhibitory effects on both standard and clinical Candida albicans strains. However, only the molecules 8, 10, 21, and 22 demonstrate some inhibitory effects on Candida parapsilosis, Candida tropicalis, and Candida glabrata strains. The structure-antifungal activity relationships of the compounds on the C. albicans strains were investigated by electron-conformational method. The pharmacophores and antipharmacophores responsible for the inhibition and non-inhibition of the C. albicans strains were obtained by electronic and geometrical characteristics of the reactive fragments of the molecules. These fragments along with the associated parameters can be used in designing the future more potent antifungal agents. It has been shown that both the positions of electronegative atoms like F and O in the pyrazole substituents and the amount of the associated charges on such atoms are crucial in regulating the strength of antifungal activity for the C. albicans strain.

Synthesis and characterisation of novel Co(II) complexes of pyrazole carboxylate derivated of sulfonamide as carbonic anhydrase inhibitors.

OBJECTIVES: Two new metal complexes, diaquabis(4-benzoyl-1,5-diphenyl-N-(5-sulfamoyl-1,3,4-thiadiazol-2-yl)-1H-pyrazole-3-carboxamide)cobalt(II) dihydrate (2) and diaquabis(ethyl-1-(3-nitrophenyl)-5-phenyl-3-(5-sulfamoyl-1,3,4-thiadiazol-2-ylcarbamoyl)-1H-pyrazole-4-carboxylate)cobalt(II) monohydrate (4), containing sulfonamide have been synthesized by the reaction of Co(II) with 4-benzoyl-1,5-diphenyl-N-(5-sulfamoyl-1,3,4-thiadiazol-2-yl)-1H-pyrazole-3-carboxamide (1) and ethyl-1-(3-nitrophenyl)-5-phenyl-3-(5-sulfamoyl-1,3,4-thiadiazol-2-ylcarbamoyl)-1H-pyrazole-4-carboxylate (3), respectively. METHODS: The structures of Co(II) complexes 2 and 4 have been characterised by spectroscopic methods and elemental analyses. Human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of ligands 3 and 4, acetazolamide as a control compound and the newly synthesized complexes on the activity of hydratase and esterase of these isoenzymes have been studied in vitro. KEY FINDINGS: The concentration of compounds 2 and 4 producing a 50% inhibition of hydratase activity (IC(50) values) were 0.473 ± 0.025 and 0.065 ± 0.002 µm for hCA-I and 0.213 ± 0.015 and 0.833 ± 0.021 µm for hCA-II, respectively. The IC(50) values of synthesized compounds 2 and 4 for esterase activity were, 0.058 ± 0.006 and 0.297 ± 0.015 µm for hCA-I and 0.110 ± 0.010 and 0.052 ± 0.002 µm for hCA-II, respectively. In relation to esterase activity, the inhibition equilibrium constants (K(i) ) were determined as 0.039 ± 0.004 and 0.247 ± 0.035 µm on hCA-I and 0.078 ± 0.002 and 0.363 ± 0.015 µm on hCA-II for 2 and 4, respectively. CONCLUSIONS: The synthesized compounds 2 and 4 had effective inhibitory activity (P < 0.0001) on hCA-I and hCA-II than the corresponding free ligands, 1 and 3, and acetazolamide. Compounds 2 and 4 might be considered as potential inhibitors.

Synthesis and characterization of metal complexes of heterocyclic sulfonamide as carbonic anhydrase inhibitors.

Three novel metal complexes of N-[5-(aminosulfonyl)-1,3,4-thiadiazol-2-yl]-4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxamide which possess strong carbonic anhydrase (CA) inhibitory properties have been synthesised. The structure of these compounds has been investigated by elemental analysis, FT-IR, LC/MS, UV-vis spectrophotometric method and magnetic susceptibility. Human carbonic anhydrase isoenzymes hCA-I and hCA-II were purified from erythrocyte cells by the affinity chromatography. The inhibitory effects of newly synthesized complexes and acetazolamide (AAZ) as a control compound on hydratase and esterase activities of these isoenzymes have been studied in vitro by comparing IC(50) and K(i) values and it has been found that the newly synthesised complexes behave as very powerful inhibitors against hCA-I and hCA-II than parent ligand (1) and than AAZ.

Inhibitory effect of novel pyrazole carboxamide derivatives on human carbonic anhydrase enzyme.

The synthesis, characterization and biological evaluation of novel pyrazole carboxamide derivatives (2-9) are presented. (1)H and (13)C NMR have been used for the structure description, possible tautomeric structures determination and hydrogen bonding observation. FT-IR results have confirmed the synthesis of the pyrazole derivatives while thermal gravimetric analysis has confirmed thermal stability up to 300°C. The melting temperatures are strongly dependent on their crystal structure as confirmed by differential scanning calorimetry and X-ray diffraction measurements. Impacts of 2-9 as possible antiglaucoma agents were investigated on carbonic anhydrase I and II (CA-I and II) isozymes purified from human erythrocytes in vitro. Compounds 3 and 9 had the highest inhibitory effect while compounds 6 and 8 showed the lowest inhibition.

Facile synthesis and characterization of novel pyrazole-sulfonamides and their inhibition effects on human carbonic anhydrase isoenzymes.

In the current study, a series of pyrazole-sulfonamide derivatives (2-14) were synthesized, characterized, and the inhibition effects of the derivatives on human carbonic anhydrases (hCA I and hCA II) were investigated as in vitro. Structures of these sulfonamides were confirmed by FT-IR, (1)H NMR, (13)C NMR and LC-MS analysis. (1)H NMR and (13)C NMR revealed the tautomeric structures. hCA I and hCA II isozymes were purified from human erythrocytes and inhibitory effects of newly synthesized sulfonamides on esterase activities of these isoenzymes have been studied. The K(i) values of compounds were 0.062-1.278 µM for hCA I and 0.012-0.379 µM for hCA II. The inhibition effects of 7 for hCA I and 4 for hCA II isozymes were almost in nanomolar concentration range.

Synthesis of 5-amino-1,3,4-thiadiazole-2-sulphonamide derivatives and their inhibition effects on human carbonic anhydrase isozymes.

In this study, some novel inhibitors were synthesised from the further stage reactions of 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carbonyl chloride with 5-amino-1,3,4-thiadiazole-2-sulphonamide 1 (inhibitor 1). They were characterised by elemental and spectral (¹H NMR, ¹³C NMR, IR) analyses. Human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of inhibitor 1, acetazolamide (2) and the 11 newly synthesised amides (8-18) on the hydratase and esterase activities of these isoenzymes (hCA-I and hCA-II) were studied in vitro. In relation to these activities, the inhibition equilibrium constants (K(i)) were determined. The K(i) values for the new compounds (8-18) were observed to be well below that of the parent compound inhibitor 1 and were also compared to 2 under the same experimental conditions. The comparison of the newly synthesised amides to inhibitor 1 and to 2 indicated that the new derivatives preferentially inhibited hCA-II and were more potent inhibitors of hCA-II than the parent inhibitor 1 and 2.

Synthesis, characterization and antiglaucoma activity of some novel pyrazole derivatives of 5-amino-1,3,4-thiadiazole-2-sulfonamide.

Pyrazole carboxylic acid derivatives of 5-amino-1,3,4-thiadiazole-2-sulfonamide (inhibitor 1) were synthesized from ethyl 3-(chlorocarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-4-carboxylate compound. The inhibitory effects of inhibitor 1, acetazolamide (AAZ) and of 11 newly synthesized amides (5a-b, 6, 7a-g, and 8) on hydratase and esterase activities of carbonic anhydrase isoenzymes (hCA-I and hCA-II) have been studied in vitro. The comparison of newly synthesized amides to inhibitor 1 and to AAZ indicated that the new derivatives inhibit CA isoenzymes and they are more potent inhibitors than the parent inhibitor 1 and AAZ.

Effects of new 5-amino-1,3,4-thiadiazole-2-sulfonamide derivatives on human carbonic anhydrase isozymes.

Pyrazole carboxylic acid amides of 5-amino-1,3,4-thiadiazole-2-sulfonamide 1 (inhibitor 1) were synthesized from 4-benzoyl-1-(4-nitrophenyl)-5-phenyl-1H-pyrazole-3-carbonyl chloride and 4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carbonyl chloride compounds. Human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from erythrocyte cells by the affinity chromatography. The inhibitory effects of inhibitor 1, acetazolamide (AAZ), and of 16 newly synthesized amides (8-11, 12a-f, 13a-c, 14a-b, and 15) on hydratase and esterase activities of these isoenzymes have been studied in vitro. The average IC(50) values of the new compounds (8-11, 12a-f, 13a-c, 14a-b, and 15) for hydratase activity ranged from 3.25 to 4.75 microM for hCA-I and from 0.055 to 2.6 microM for hCA-II. The mean IC(50) values of the same inhibitors for esterase activity were in the range of 2.7-6.6 microM for hCA-I (with the exception of inhibitor 10, which did not inhibit the esterase activity of hCA-I) and of 0.013-4.2 microM for hCA-II. The K(i) values for new compounds (8-11, 12a-f, 13a-c, 14a-b, and 15) were observed well below that of the parent compound inhibitor 1 and were also comparable to that of AAZ under the same experimental conditions. The comparison of newly synthesized amides to inhibitor 1 and to AAZ indicated that the new derivatives preferentially inhibit hCA-II and are more potent inhibitors of hCA-II than the parent inhibitor 1 and AAZ.

Amide derivatives with pyrazole carboxylic acids of 5-amino-1,3,4-thiadiazole 2-sulfonamide as new carbonic anhydrase inhibitors: synthesis and investigation of inhibitory effects.

Pyrazole carboxylic acid amides of 5-amino-1,3,4-thiadiazole-2-sulfonamide were synthesized from 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride and 4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carbonyl chloride. Carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from human erythrocyte cells by the affinity chromatography method. The inhibitory effects of 5-amino-1,3,4-thiadiazole-2-sulfonamide 1, acetazolamide 2 and new synthesized amides on these isozymes have been studied in vitro. The I(50) concentrations (the concentration of inhibitor producing a 50% inhibition of CA activity) against hydratase activity ranged from 1.2 to 2.2 nM for hCA-I and from 0.4 to 2 nM for hCA-II. The I(50) values against esterase activity ranged from 1.4 to 8 nM for hCA-I and from 1.3 to 6 nM for hCA-II. The K(i) values were observed between 8.2 x 10(- 5) to 6.2 x 10(- 4) M for hCA-I and between 2.9 x 10(- 4) to 8.2 x 10(- 4) M for hCA-II. The comparison of new synthesized amides to 5-amino-1,3,4-thiadiazole-2-sulfonamide 1, acetazolamide 2 indicated that the new synthesized compounds (18-23) inhibit CA activity more potently than the parent compounds.