Synthesis and evaluation of sulfonamide-bearing thiazole as carbonic anhydrase isoforms hCA I and hCA II

Sulfonamide-bearing thiazole compounds were synthesized and their inhibitory effects on the activity of purified human carbonic anhydrase I and II were evaluated. Human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were purified from erythrocyte cells by affinity chromatography. The inhibitory effects of the 12 synthesized sulfonamide (5a–l) 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 (Ki) were determined. The results showed that all the synthesized compounds inhibited the CA isoenzyme activity. Among them 5b was found to be the most active (IC_50?=_?0.35?μM; Ki: 0.33?μM) for hCA I and hCA II.     

In vitro inhibition of cytosolic carbonic anhydrases I and II by some new dihydroxycoumarin compounds

A new series of 6, 7-dihydroxy-3-(methylphenyl) chromenones, including three new derivatives, i.e. 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (OPC); 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (MPC); 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (PPC) and one previously described, namely 6,7-dihydroxy-3-phenyl-2H-chromen-2-one (DPC), were synthesized. These compounds were investigated as inhibitors of human carbonic anhydrase I (hCA-I) and human carbonic anhydrase II (hCA-II) which had been purified from human erythrocytes on an affinity gel comprised of L-tyrosine-sulfonamide-Sepharose 4B.     

Influence of Chirality of Benzimidazole Amine Hybrids on Inhibition of Human Erythrocytes Carbonic Anhydrase I,II and Acetylcholinesterase

Novel chiral benzimidazole amine hybrids ( 4a – 4d ) were synthesized from commercially available amine [(R)- (+)-phenylethylamine, (−) (S)-(-)-phenylethylamine, (−) (R)-(-)-cyclohexylethylamine, (S)-(+)-cyclohexylethylamine] and 2-(chloromethyl)-N-tosyl-1H-benzimidazole. The synthesized compounds ( 4a – 4d ) were characterized by IR, NMR, and LC/MS analysis. The inhibitory effect of 4a – 4d on human erythrocytes carbonic anhydrase I (hCA-I), II (hCA-II), and acetylcholinesterase (AChE) activity was investigated. For hCA-I, the IC₅₀ values of 4a – 4d were found to be 4.895 μM, 1.750 μM, 0.173 μM, and 0.620 μM, respectively, and for hCA-II, the IC₅₀ values of 4a – 4d were found to be 0.469 μM, 0.380 μM, 0.233 μM, 0.635 μM, respectively. Furthermore, IC₅₀ values of 4a – 4d on AChE were found as 87.5 nM, 100 nM, 26.92 nM, and 100 nM, respectively. In addition, molecular docking analysis was performed to evaluate the affinity of 4a – 4d against hCA-I, hCA-II, and AChE and explain their binding interactions.     

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 I₅₀ 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 I₅₀ 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 8.2·10^{? 5} to 6.2·10^{? 4} M for hCA-I and between 2.9·10^{? 4} to 8.2·10^{? 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.     

In vitro inhibition effects of some new sulfonamide inhibitors on human carbonic anhydrase I and II

A new series of aromatic and heterocyclic sulfonamides, including six new derivatives, 2-(3-cyclohexene-1-carbamido)-1,3,4-thiadiazole-5-sulfonamide (CCTS), 4-(3-cyclohexene-1-carbamido) methyl-benzenesulfonamide (CCBS), 2-(9-octadecenoylamido)-1,3,4-thiadiazole-5-sulfonamide (ODTS), 2-(4,7,10-trioxa-tetradecanoylamido)-1,3,4-thiadiazole-5-sulfonamide (TDTS), 2-(coumarine-3-carbamido)-1,3,4-thiadiazole-5-sulfonamide (COTS) and 2-(8-methoxycoumarine-3-carbamido)-1,3,4-thiadiazole-5-sulfonamide (MCTS), has been investigated. These sulfonamides were assayed for inhibition of human carbonic anhydrase I (hCA-I) and human carbonic anhydrase II (hCA-II) which were purified by affinity chromatography.     

In vitro inhibition of cytosolic carbonic anhydrases I and II by some new dihydroxycoumarin compounds

A new series of 6, 7-dihydroxy-3-(methylphenyl) chromenones, including three new derivatives, i.e. 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (OPC); 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (MPC); 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (PPC) and one previously described, namely 6,7-dihydroxy-3-phenyl-2H-chromen-2-one (DPC), were synthesized. These compounds were investigated as inhibitors of human carbonic anhydrase I (hCA-I) and human carbonic anhydrase II (hCA-II) which had been purified from human erythrocytes on an affinity gel comprised of L-tyrosine-sulfonamide-Sepharose 4B.     

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 IC₅₀ 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 μM for hCA-I and from 0.055 to 2.6 μM for hCA-II. The mean IC₅₀ values of the same inhibitors for esterase activity were in the range of 2.7–6.6 μM 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 μM 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.     

Inhibition of mammalian carbonic anhydrase isoforms I,II and VI with thiamine and thiamine-like molecules

Here we determined the in vitro inhibitory effects of 5-(2-hydroxyethyl)-3,4-dimethylthiazolium iodide (1), 3-Benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride (2) and thiamine (3) on human erythrocyte carbonic anhydrase I, II isozymes (hCA I and hCA II) and secreted isoenzyme CA VI. K_I values ranged from 0.38 to 2.27 µM for hCA I, 0.085 to 0.784 µM for hCA II and 0.062 to 0.593 µM for hCA VI, respectively. The compounds displayed relatively strong actions on hCA II, in the same range as the clinically used sulfonamidesethoxzolamide, zonisamide and acetazolamide.     

Synthesis and characterisation of two novel proton transfer compounds and their inhibition studies on carbonic anhydrase isoenzymes

Two novel proton transfer compounds were prepared between 2,4-dichloro-5-sulphamoylbenzoic acid (lasamide) (Hsba) and ethylenediamine (en), namely ethane-1,2-diaminium 2,4-dichloro-5-sulphamoylbenzoate (1), and also between Hsba and 2-amino-3-methylpyridine (2-amino-3-picoline) (amp), namely 2-amino-3-methylpyridinium 2,4-dichloro-5-sulphamoylbenzoate (2). All these were characterised by elemental, spectral (IR and UV-vis), thermal analyses, and single crystal X-ray diffraction studies. Compounds 1 and 2 crystallised in the P-1 and P21/c space groups, respectively. Intermolecular non-covalent interactions, such as ion pairing, hydrogen bonding, and π-π stacking were observed for these ionic compounds. The free ligands Hsba, en and amp, the products 1 and 2, and acetazolamide (AAZ) as the control compound, were also evaluated for their in vitro inhibitor effects on the human carbonic anhydrase isoenzymes (hCA I and hCA II) purified from erythrocyte cells by affinity chromatography for their hydratase and esterase activities. The half maximal inhibitory concentration (IC₅₀) values for products 1 and 2 with respect to hydratase activity are 0.15 and 0.32 µM for hCA I and 0.06 and 0.15 µM for hCA II, respectively. The IC₅₀ values of the same inhibitors for esterase activity are 0.13 and 0.8 µM for hCA I and 0.14 and 0.1 µM for hCA II, respectively. In relation to esterase activities, the inhibition equilibrium constants (Ki) were also determined and found to be 0.137 and 0.99 µM on hCA I and 0.157 and 0.075 µM on hCA II for 1 and 2, respectively. The comparison of the inhibition studies of the newly synthesised compounds 1 and 2 to the parent compounds Hsba and amp and also to AAZ indicated that 1 and 2 have an effective inhibitory activity on hCA I and II, and might be used as potential inhibitors.     

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.     

Synthesis of pro-apoptotic indapamide derivatives as anticancer agents

Abstract

4-Chloro-3-({[(substitutedamino)carbonothioyl]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide (1–20) and 4-chloro-3-({[3-(substituted)-4-oxo-1,3-thiazolidine-2-ylidene]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide derivatives (21–31) were synthesized from 4-chloro-N-(2-methyl-2,3-dihydroindol-1-yl)-3-sulfamoylbenzamide (indapamide). 4-Chloro-3-({[(4-chlorophenyl) amino) carbonothioyl]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide 12 demonstrated the highest proapoptotic activity among all synthesized compounds on melanoma cell lines MDA–MB-435 with 3.7% growth inhibition at the concentration of 10?µM. Compound 12 (SGK 266) was evaluated in vitro using the MTT colorimetric method against melanoma cancer cell line MDA–MB435 growth inhibition for different doses and exhibited anticancer activity with IC₅₀ values of 85–95?µM against melanoma cancer cell line MDA–MB435. In addition, this compound was investigated as inhibitors of four physiologically relevant human carbonic anhydrase isoforms, hCA I, II, IX and XII. The compund inhibited these enzymes with IC₅₀ values ranging between 0.72 and 1.60?µM.     

Synthesis of novel sulfonamides under mild conditions with effective inhibitory activity against the carbonic anhydrase isoforms I and II

Novel sulfonamide derivatives 6a–i, as new carbonic anhydrase inhibitors which candidate for glaucoma treatment, were synthesized from the reactions of 4-amino-N-(4-sulfamoylphenyl) benzamide 4 and sulfonyl chloride derivatives 5a–i with high yield (71–90%). The structures of these compounds were confirmed by using spectral analysis (FT-IR, ¹H NMR, ¹³C NMR, LC/MS and HRMS). The inhibition effects of 6a–i on the hydratase and esterase activities of human carbonic anhydrase isoenzymes, hCA I and II, which were purified from human erythrocytes with Sepharose®4B-l-tyrosine-p-aminobenzene sulfonamide affinity chromatography, were studied as in vitro, and IC₅₀ and K_i values were determined. The results show that newly synthesized compounds have quite powerful inhibitory properties.     

The inhibitory effects of phenolic Mannich bases on carbonic anhydrase I and II isoenzymes

Phenolic mono Mannich bases [2-[4-hydroxy-3-(aminomethyl)benzylidene]-2,3-dihydro-1H-inden-1-one (8–15)] and bis Mannich bases [2-[4-hydroxy-3,5-bis(aminomethyl)benzylidene]-2, 3-dihydro-1H-inden-1-one (2–7)] were synthesized starting from 2-(4-hydroxybenzylidene)-2, 3-dihydro-inden-1-one (1). This study was designed in order to investigate the carbonic anhydrase (CA, EC 4.2.1.1) inhibitory properties of a library of compounds incorporating the phenol functional group. All prepared compounds showed a low inhibition percentages on both human (h) isoforms hCA I and hCA II compared to the reference sulfonamide acetazolamide. Mannich bases 2–15 had lower inhibition percentages than the compound 1 on hCA I and hCA II, except compound 14, which is a Mannich base derivative of dipropylamine, which had a similar inhibitory power as compound 1 on hCA II. All compounds synthesized 1–15 were 1.3–1.9 times more effective on hCA II comparing with the effectivenes of the compounds on hCA I.     

Synthesis and carbonic anhydrase inhibitory properties of novel 4-(2-aminoethyl)benzenesulfonamide-dipeptide conjugates

Thirty novel sulfonamide derivatives incorporating dipeptide were synthesized by facile acylation through benzotriazole mediated reactions and their structures were identified by ¹H NMR, ¹³C NMR, MS and FT-IR spectroscopic techniques and elemental analysis. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against four human (h) isoforms, hCA I, hCA II, hCA IV and hCA XII. Most of the synthesized compounds showed excellent in vitro carbonic anhydrase inhibitory properties comparable to those of the clinically used drug acetazolamide (AAZ). The new unprotected dipeptide-sulfonamide conjugates showed very effective inhibitory activity, in the low nanomolar range against II and XII, being less effective as hCA I and IV inhibitors. Four of the thirty compounds also showed strong inhibitory activity against hCA XII compared to AAZ.     

Synthesis,antioxidant and carbonic anhydrase I and II inhibitory activities of novel sulphonamide-substituted coumarylthiazole derivatives

New secondary benzenesulphonamide-substituted coumarylthiazole derivatives were synthesized and their inhibitory effects on purified carbonic anhydrase I and II were evaluated using CO₂ as a substrate. The result showed that all the synthesized compounds exhibited inhibitory activity on both hCA I and hCA II with N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)naphthalene-2-sulphonamide (5f, IC₅₀ value of 5.63 and 8.48?µM, against hCA I and hCA II, respectively) as the strongest inhibitor revealed from this study. Structure–activity relationship revealed that the inhibitory activity of the synthesized compounds is related to the type of the halogen and bulky substituent on the phenyl ring. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. 4-methoxy-N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)benzenesulphonamide (5e) exhibited the strongest ABTS and CUPRAC activity with IC₅₀ value of 48.83?µM and A_0.50 value of 23.29?µM, respectively.     

Carbonic anhydrase inhibitory properties of some uracil derivatives

Inhibitors of carbonic anhydrase (CA) have been carried out in many therapeutic applications, especially antiglaucoma activity. In this study, we investigated some uracil derivatives (4–12) to inhibit human CA I (hCA I) and II (hCA II) isoenzymes. The K_I values of the compounds 4–12 are in the range of 0.085–428?µM for hCA I and of 0.1715–645?µM against hCA II, respectively. It is concluded from the kinetic investigations, all compounds used in the study act as competitive inhibitors with substrate, 4-NPA. Uracil derivatives are emerging agents for the inhibiton of carbonic anhydrase which could be used in biomedicine.     

A novel proton transfer salt of 2-amino-6-sulfamoylbenzothiazole and its metal complexes: the evaluation of their inhibition effects on human cytosolic carbonic anhydrases

A novel proton transfer compound (SMHABT)⁺(HDPC)^? (1) obtained from 2-amino-6-sulfamoylbenzothiazole (SMABT) and 2,6-pyridinedicarboxylic acid (H₂DPC) and its Fe(III), Co(II), Ni(II) complexes (2–4), and Fe(II) complex of SMABT (5) have been prepared and characterized by spectroscopic techniques. Additionally, single crystal X-ray diffraction techniques were applied to complexes (2–4). All complexes (2–4) have distorted octahedral conformations and the structure of 5 might be proposed as octahedral according to spectral and analytical results. All compounds, including acetazolamide (AAZ) as the control compound, were also evaluated for their in vitro inhibition effects on human hCA I and hCA II for their hydratase and esterase activities. The synthesized compounds have remarkable inhibitory activities on hCA I and hCA II. Especially, the inhibition potentials of the salt and the metal complexes (1–5) are comparable with AAZ. Inhibition data have been analyzed by using a one-way analysis of variance for multiple comparisons (p?相似文献   

Synthesis and carbonic anhydrase inhibitory properties of novel coumarin derivatives

A newly series of water-soluble 1-alkyl-3-(4-methyl-7, 8-dihydroxy-2H-chromen-2-one) benzimidazolium chloride salts (3a-j) were synthesized and their inhibitory effects on the activity of purified human carbonic anhydrase (hCA) I and II were evaluated. hCA I and II from human erythrocytes were purified by a simple one step procedure by using Sepharose 4B-L-tyrosine-sulphanilamide affinity column. The result showed that all the synthesized compounds were inhibited the CA isoenzymes activity. Among them, 3g and 3j were found to be most active (IC₅₀ = 22.09 µM and 20.33 µM) for hCA I and hCA II, respectively.     

Synthesis,cytotoxicity and carbonic anhydrase inhibitory activities of new pyrazolines

Abstract

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.     

Carbonic Anhydrase Inhibitors. Metal Complexes of 5-(2-Chlorophenyl)-1, 3, 4-Thiadiazole-2-Sulfonamide with Topical Intraocular Pressure Lowering Properties: The Influence of Metal Ions Upon the Pharmacological Activity

Metal complexes of a sulfonamide possessing strong carbonic anhydrase (CA) inhibitory properties, 5-(2-chlorophenyl)-1, 3, 4-thiadiazole-2-sulfonamide (chlorazolamide) have been obtained from the sodium salt of the sulfonamide and the following metal ions: Mg(II), Zn(II), Mn(II), Cu(II), Co(II), Ni(II), Be(II), Cd(II), Pb(II), AI(III), Fe(III) and La(III). The original sulfonamide and its complexes were assayed for the in vitro inhibition of three CA isozymes, CA I, II, and IV, some of which play a critical role in ocular fluid secretion. All these compounds (the sulfonamide and its metal complexes) behaved as powerful inhibitors against the three investigated isozymes. The parent sulfonamide possessed an extremely weak topical pressure lowering effect when administered as a 1-2% suspension into the rabbit eye, but some of its metal complexes, such as the Mg(II), Zn(II), Mn(II) and Cu(II) derivatives, lower intraocular pressure (IOP) in experimental animals very well. Ex vivo data showed a 99.5-99.9% CA II inhibition in ocular fluids and tissues of rabbits treated with these agents, proving that the observed IOP lowering is due to CA inhibition. The influence of the different metal ions upon the efficiency of the obtained complexes as pressure lowering drugs are discussed, leading to the possibility of designing more selective; potent pharmacological agents from this class