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Heterocyclic amines and acetamide derivatives are known for their chemotherapeutic potential. Hence, in the present study, morpholine was taken as a principal product and novel morpholine derivatives were designed, formulated, characterized, and screened for the mechanism of inhibition of carbonic anhydrase and their anticancer potential. In addition, in vitro inhibition of hypoxia-inducible factor-1 (HIF-1) protein was also investigated. Results revealed that compounds 1c, 1d, and 1h possessed significant inhibitory activities against carbonic anhydrase with IC50 of 8.80, 11.13, and 8.12 μM, respectively. Interestingly, the carbonic anhydrase inhibitory activity of compound 1h was comparable with that of standard acetazolamide (IC50 7.51 μM). The compounds 1h and 1i significantly inhibited the proliferation of ovarian cancer cell line ID8 with IC50 of 9.40, and 11.2 μM, respectively while the standard cisplatin exhibited an IC50 8.50 μM. In addition, compounds 1c, 1b, 1h and 1i also exhibited significant inhibitory effects on HIF-1α. In conclusion, we report first time the biological potential of morpholine based compounds against ovarian cancer and HIF-1α that may serve as lead molecules for drug discovery.

Carbonic anhydrases (CAs) are a metalloenzyme family that have important roles in cellular processes including pH homeostasis and have been implicated in multiple pathological conditions. Small molecule inhibitors have been developed to target carbonic anhydrases, but the effects of post-translational modifications (PTMs) on the activity and inhibition profiles of these enzymes remain unclear. Here, we investigate the effects of phosphorylation, the most prevalent carbonic anhydrase PTM, on the activities and drug-binding affinities of human CAI and CAII, two heavily modified active isozymes. Using serine to glutamic acid (S > E) mutations to mimic the effect of phosphorylation, we demonstrate that phosphomimics at a single site can significantly increase or decrease the catalytic efficiencies of CAs, depending on both the position of the modification and the CA isoform. We also show that the S > E mutation at Ser50 of hCAII decreases the binding affinities of hCAII with well-characterized sulphonamide inhibitors including by over 800-fold for acetazolamide. Our findings suggest that CA phosphorylation may serve as a regulatory mechanism for enzymatic activity, and affect the binding affinity and specificity of small, drug and drug-like molecules. This work should motivate future studies examining the PTM-modification forms of CAs and their distributions, which should provide insights into CA physiopathological functions and facilitate the development of 'modform-specific' carbonic anhydrase inhibitors. [ABSTRACT FROM AUTHOR]

In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)– (1) and (ClHabt)+(pabsmal)– (2), were obtained from 2-amino-6-chlorobenzo­thiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoyl­phenyl)maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (1H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 µM and 4.25 ± 0.100 µM for hCA I, and of 0.02 ± 0.001 µM and 3.21 ± 0.200 µM for hCA II.

In this study, two new proton transfer salts of sulfonamide derivatives of maleic acid, namely (ClHabt)+(mabsmal)- (1) and (ClHabt)+(pabsmal)- (2), were obtained from 2-amino-6-chlorobenzothiazole (Clabt) and N-(3-sulfamoylphenyl)maleamide acid (Hmabsmal) and N-(4-sulfamoylphenyl) maleamide acid (Hpabsmal), respectively. Also, the Cu(II) complexes (3 and 4) of salts (1 and 2) and of Hmabsmal (5) were prepared. Compounds 1‒5 were characterized by elemental, NMR (¹H and 13C), FTIR, and thermal analyses, as well as UV-Vis, magnetic moment, and molar conductivity measurements. Carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocyte cells by affinity chromatography. The effects of the synthesized compounds on the hydratase and esterase activities of CA isoenzymes were studied in vitro. The results reveal that the synthesized compounds inhibit both esterase and hydratase activities of hCA I and hCA II. The inhibition constants of the compounds (Ki) were determined according to the esterase activity measurements. Ki values of 1‒5 are in the range of 0.06 ± 0.003 μM and 4.25 ± 0.100 μM for hCA I, and of 0.02 ± 0.001 μM and 3.21 ± 0.200 μM for hCA II. [ABSTRACT FROM AUTHOR]

Introduction: Traditional healers' assertions that Quercus leucotrichophora A. Camus is a plant that has been used in traditional medicine to treat various urinary and renal diseases, thus the present study aims to investigate the diuretic activity of the methanolic extract of seeds in rats. Methods: Dried course powder was extracted with methanol using soxhlet extraction. Male Wistar rats were given a control (normal saline, 15 ml), a reference medication (furosemide, 13 mg/kg), and three separate doses (250 mg/kg, 375 mg/kg, and 500 mg/kg) of the extract orally. Urine volume, urinary electrolytes, urine pH, and conductivity were measured to establish the extract's diuretic activity. The urine outflow was tested at 6, 12, and 24 h, as well as electrolyte content, pH, and conductivity. Creatinine, urea, aldosterone, and electrolyte concentrations in plasma and urine samples were also determined. The index kidney function was determined by analyzing kidney homogenate. One-way ANOVA was used to evaluate the data. Results: The findings demonstrated that the extract increased diuresis in a dose-dependent manner, i.e., at 500 mg/kg, the extract exhibited significant diuretic effects (p

Rationale: Current therapies for obstructive sleep apnea (OSA) are limited by insufficient efficacy, compliance, or tolerability. An effective pharmacological treatment for OSA is warranted. Carbonic anhydrase inhibition has been shown to ameliorate OSA. Objectives: To explore safety and tolerability of the carbonic anhydrase inhibitor sulthiame (STM) in OSA. Methods: A 4-week double-blind, randomized, placebo-controlled dose-guiding trial was conducted in patients with moderate and/or severe OSA not tolerating positive airway pressure treatment. Measurements and Main Results: Intermittent paresthesia was reported by 79%, 67%, and 18% of patients receiving 400 mg STM (n = 34), 200 mg STM (n = 12), and placebo (n = 22), respectively. Dyspnea was reported after 400 mg STM (18%). Six patients in the higher dose group withdrew because of adverse events. There were no serious adverse events. STM reduced the apnea-hypopnea index from 55.2 to 33.0 events/h (-41.0%) in the 400-mg group and from 61.1 to 40.6 events/h (-32.1%) after 200 mg (P < 0.001 for both). Corresponding placebo values were 53.9 and 50.9 events/h (-5.4%). The apnea-hypopnea index reduction threshold of ⩾50% was reached in 40% of patients after 400 mg, 25% after 200 mg, and 5% after placebo. Mean overnight oxygen saturation improved by 1.1% after 400 and 200 mg (P < 0.001 and P = 0.034, respectively). Patient-related outcomes were unchanged. Conclusions: STM showed a satisfactory safety profile in moderate and/or severe OSA. STM reduced OSA, on average, by more than 20 events/h, one of the strongest reductions reported in a drug trial in OSA. Larger scale clinical studies of STM in OSA are justified. Clinical trial registered with www.clinicaltrialsregister.eu (2017-004767-13). [ABSTRACT FROM AUTHOR]

The hypothesis that sulfocoumarin acting as inhibitors of human carbonic anhydrase (CA, EC 4.2.1.1) cancer-associated isoforms hCA IX and – hCA XII is being able to also inhibit thioredoxin reductase was verified and confirmed. The dual targeting of two cancer cell defence mechanisms, i.e. hypoxia and oxidative stress, may both contribute to the observed antiproliferative profile of these compounds against many cancer cell lines. This unprecedented dual anticancer mechanism may lead to a new approach for designing innovative therapeutic agents.

A hypothesis that simultaneous targeting cancer-related carbonic anhydrase hCA IX and hCA XII isoforms (whose overexpression is a cancer cell’s defence mechanism against hypoxia) along with thioredoxin reductase (overexpressed in cancers as a defence against oxidative stress) may lead to synergistic antiproliferative effects was confirmed by testing combinations of the two inhibitor classes against pancreatic cancer cells (PANC-1). Combining both pharmacophoric motifs within one molecule led to a sharp increase of cytotoxicity. This preliminary observation sets the ground for a fundamentally new approach to anticancer agent design.

4-[(2,2-Dicyanoethenyl)amino]benzenesulfonamides were synthesized by condensation of malono-nitrile with the corresponding benzenesulfonamide derivatives and triethyl orthoformate in butan-2-ol used as solvent. The structure of the synthesized compounds was confirmed by 1H and 13C NMR spectral data. The synthesized compounds were screened for their in vitro antioxidant, antibacterial, antifungal, antiurease, and carbonic anhydrase inhibitory activities, and some of them showed excellent antioxidant and antibacterial activities. [ABSTRACT FROM AUTHOR]

Novel monopeptide-anthraquinone conjugates (1-16) were synthesized by the reaction of appropriate N-protected amino acid with 2-hydroxymethylanthraquinone in good or high yields. The structural elucidation of the new compounds was accomplished by ½H NMR, 13C NMR, MS, FT-IR spectroscopy and elemental analysis techniques. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was determined against two human (h) isoforms, hCA I and hCA II. While three of the sixteen compounds showed moderate in vitro carbonic anhydrase inhibitory properties against hCA II with inhibition constants in the micromolar level (43.5, 67.4 and 78.1 µM), they did not show inhibitory activity against hCA I up to 100 µM concentration. The antioxidant abilities of the compounds were determined using the 1,1-diphenyl-2-picrylhydrazil (DPPH) radical scavenging method, ferric ion reducing assay and metal chelation methods. While a small amount of antioxidant activity was observed according to the DPPH and ferric ion reducing power assay methods, none of the compounds showed antioxidant properties according to the metal chelating activity method at the concentrations studied. [ABSTRACT FROM AUTHOR]

3-Methylpentyl(4-sulphamoylphenyl)carbamate (MSPC) came as the most potent compound out of a new series of carbamates composed of phenyl-ethanol or branched aliphatic alcohols, and 4-benzenesulphonamide-carbamic acid. In this study, the anticonvulsant activity and pharmacokinetics (PKs) of MSPC-two individual enantiomers were comparatively analysed in rats as well as their carbonic anhydrase (CA) inhibition. The anticonvulsant activity of MSPC enantiomers was evaluated at the rat-maximal electroshock (MES) test, and their CA inhibition evaluated. (R)-MSPC had a 29% higher clearance and consequently, a lower plasma exposure area under the curve (AUC) than (S)-MSPC and racemic-MSPC. Nevertheless, (R)-MSPC had a better brain permeability than its (S)-enantiomer with brain-to-plasma-(AUC)-ratio (BPR) of 2.07 ((R)-enantiomer), 1.85 (racemate), and 0.79 ((S)-enantiomer). As a whole body (in vivo) pharmacodynamic (PD) measure, MSPC-anticonvulsant maximal electroshock seizure (MES) activity was less enantioselective than MSPC-CA inhibition. The lack of significant differences between racemic-MSPC and its individual enantiomers suggest that their anticonvulsant activity might be due to multiple mechanisms of action.

Up to date alcohols have been scarcely investigated as carbonic anhydrase (CA) inhibitors. To get more insights into the CA inhibition properties of this class of molecules, in this paper, by means of inhibition assays and X-ray crystallographic studies we report a detailed characterization of the CA inhibition properties and the binding mode to human CA II of benzyl alcohol. Results show that, although possessing a very simple scaffold, this molecule acts as a micromolar CA II inhibitor, which anchors to the enzyme active site by means of an H-bond interaction with the zinc bound solvent molecule. Taken together our results clearly indicate primary alcohols as a class of CA inhibitors that deserve to be more investigated. [Display omitted] • Alcohols have been scarcely investigated as carbonic anhydrase inhibitors (CAIs). • Benzyl alcohol inhibits CAs by anchoring to the zinc-bound water molecule. • Derivatization of benzyl alcohol ring could allow obtaining selective CAIs. [ABSTRACT FROM AUTHOR]

A hypothesis that simultaneous targeting cancer-related carbonic anhydrase hCA IX and hCA XII isoforms (whose overexpression is a cancer cell's defence mechanism against hypoxia) along with thioredoxin reductase (overexpressed in cancers as a defence against oxidative stress) may lead to synergistic antiproliferative effects was confirmed by testing combinations of the two inhibitor classes against pancreatic cancer cells (PANC-1). Combining both pharmacophoric motifs within one molecule led to a sharp increase of cytotoxicity. This preliminary observation sets the ground for a fundamentally new approach to anticancer agent design. [ABSTRACT FROM AUTHOR]

The hypothesis that sulfocoumarin acting as inhibitors of human carbonic anhydrase (CA, EC 4.2.1.1) cancer-associated isoforms hCA IX and – hCA XII is being able to also inhibit thioredoxin reductase was verified and confirmed. The dual targeting of two cancer cell defence mechanisms, i.e. hypoxia and oxidative stress, may both contribute to the observed antiproliferative profile of these compounds against many cancer cell lines. This unprecedented dual anticancer mechanism may lead to a new approach for designing innovative therapeutic agents. [ABSTRACT FROM AUTHOR]

3-Methylpentyl(4-sulphamoylphenyl)carbamate (MSPC) came as the most potent compound out of a new series of carbamates composed of phenyl-ethanol or branched aliphatic alcohols, and 4-benzenesulphonamide-carbamic acid. In this study, the anticonvulsant activity and pharmacokinetics (PKs) of MSPC-two individual enantiomers were comparatively analysed in rats as well as their carbonic anhydrase (CA) inhibition. The anticonvulsant activity of MSPC enantiomers was evaluated at the rat-maximal electroshock (MES) test, and their CA inhibition evaluated. (R)-MSPC had a 29% higher clearance and consequently, a lower plasma exposure area under the curve (AUC) than (S)-MSPC and racemic-MSPC. Nevertheless, (R)-MSPC had a better brain permeability than its (S)-enantiomer with brain-to-plasma-(AUC)-ratio (BPR) of 2.07 ((R)-enantiomer), 1.85 (racemate), and 0.79 ((S)-enantiomer). As a whole body (in vivo) pharmacodynamic (PD) measure, MSPC-anticonvulsant maximal electroshock seizure (MES) activity was less enantioselective than MSPC-CA inhibition. The lack of significant differences between racemic-MSPC and its individual enantiomers suggest that their anticonvulsant activity might be due to multiple mechanisms of action. [ABSTRACT FROM AUTHOR]

Twenty seven (1–27) known natural organic compounds were isolated for first time from two species of Iris, i.e. loczyi and Iris unguicularis. The structures of these compounds were deduced from the spectral data of NMR, IR, and mass spectrogram. These were evaluated against urease and carbonic anhydrase inhibition studies. For carbonic anhydrase-II inhibition studies, these compounds were evaluated by biochemical mechanism based in vitro bio-assay. Some compounds showed significant inhibition against CA-II enzyme. Compartively, compound (12) showed IC50 value of 17.60 ± 0.08 μM against urease enzyme, while compound (3) was found to be most active against carbonic anhydrase-II, having an IC50 value of 66.27 ± 0.89 μM. Izalpinin (3), 5,7-dihydroxy-2′,6-dimethoxyisoflavone (9), 4′,5,7-trihydroxy-6-methoxyflavanone (16), 4′,5,7-trihydroxy-3′,8-dimethoxyflavanone (20), 8-methoxyeriodictyol (21), and mangiferin (26) were found to be dual inhibitors of both the enyzmes. The most active compounds were docked using Autodock Vina and i-GEMDOCK softwares. The docking and in-vitro results are in agreement which showed secondary interactions with the enzymes. The compounds can serve as therapeutic agents to treat urease and carbonic anhydrase associated disorders. [ABSTRACT FROM AUTHOR]

Compounds 15, 45, 47, and 26 exhibited potent selective inhibitory activity against human isoforms CA I, II, IX, and XII (K I s: 39.4, 0.73, 1.6, and 5.2 nM, respectively), comparable to that of acetazolamide (AAZ) as a standard inhibitor (K I : 250.0, 12.0, 25.0, and 5.7 nM respectively). • Quinazoline-linked benzensulfonamides with CA inhibitory activity were synthesized. • Newly synthesized compounds potently inhibit human isoforms CA I, II, IX and XII. • Inhibitory activity of new compounds was comparable to that of CA inhibitor AAZ. • Compounds 14–15, 17, 19–21, 24–25, 28–29, 31, 35, 45, 47, 49&51 inhibit hCA I (K I s: 39.4–354.7 nM). • Compounds 15, 20, 24, 28, 29, 45, and 47 inhibit hCA II (K I s: 0.73–16.5 nM). • Compounds 13–29, 31–32, and 45–51 inhibit hCA IX (K I s: 1.6–32.2 nM). Carbonic anhydrase (CA) inhibitory activities of newly synthesized quinazoline-linked benzensulfonamides 10 – 29 , 31 , 32 , 35 , 36, and 45 – 51 against human CA (hCA) isoforms I, II, IX, and XII were measured and compared to that of acetazolamide (AAZ) as a standard inhibitor. Potent selective inhibitory activity against hCA I was exerted by compounds 14 , 15 , 17 , 19 , 20 , 21 , 24 , 25 , 28 , 29 , 31 , 35 , 45 , 47 , 49, and 51 with inhibition constant (K I s) values of 39.4–354.7 nM that were nearly equivalent or even greater than that of AAZ (K I , 250.0 nM). Compounds 15 , 20 , 24 , 28 , 29 , 45 and 47 proved to have inhibitory activities against hCA II with (K I s, 0.73–16.5 nM) that were similar or improved to that of AAZ (K I , 12.0 nM). Compounds 13 – 29 , 31 – 32, and 45 – 51 displayed potent hCA IX inhibitory activities (K I s, 1.6–32.2 nM) that were more effective than or nearly equal to AAZ (K I , 25.0 nM). Compounds 14 , 15 , 20 , 21 , 26 , 45, and 47 exerted potent hCA XII inhibitory activities (K I s, 5.2–9.2 nM), indicating similar CAI activities as compared to that of AAZ (K I , 5.7 nM). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesis of trimellitimides incorporating benzenesulfonamides and carboxylates. • Anti-inflammatory, ulcerogenic and cyctotoxic activities were studied. • The derivatives were investigated as COX-1/2 inhibitors. • The derivatives were elucidated as hCA I, II, IV and IX inhibitors. • Sulfonamide derivatives exhibited the best inhibitory activity against COX-2 and CA. Abstract Trimellitimides 6 – 21 were prepared and investigated in vivo for anti-inflammatory and ulcerogenic effects and in vitro for cytotoxicity. They were subjected to in vitro cyclooxygenase (COX-1/2) and carbonic anhydrase inhibition protocols. Compounds 6 – 11 and 18 exhibited anti-inflammatory activities and had median effective doses (ED 50) of 34.3–49.8 mg kg−1 and 63.6–86.6% edema inhibition relative to the reference drug celecoxib (ED 50 : 33.9 mg kg−1 and 85.2% edema inhibition). Compounds 6 – 11 and 18 were weakly cytotoxic at 10 μM against 59 cell lines compared with the reference standard 5-fluorouracil (5-FU). Compounds 6 – 11 had optimal selectivity against COX-2. The selectivity index (SI) range was >200–490 and was comparable to that for celecoxib [COX-2 (SI) > 416.7]. In contrast, compounds 12 , 13 , and 16 – 18 were nonselective COX inhibitors with a selectivity index range of 0.92–0.25. The carbonic anhydrase inhibition assay showed that sulfonamide incorporating trimellitimides 6 – 11 inhibited the cytosolic isoforms hCA I and hCA II, and tumor-associated isoform hCA IX. They were relatively more susceptible to inhibition by compounds 8 , 9 , and 11. The K I ranges were 54.1–81.9 nM for hCA I, 25.9–55.1 nM for hCA II, and 46.0–348.3 nM for hCA IX. © 2018 Elsevier Science. All rights reserved. [ABSTRACT FROM AUTHOR]

Abstract Background Recent studies from our laboratory show the cardioprotective action of benzolamide (BZ, carbonic anhydrase inhibitor) against ischemia-reperfusion injury. However, the mechanisms involved have not been fully elucidated. Objective To examine the participation of the endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) in the effects of BZ in a model of regional ischemia. Methods Isolated rat hearts perfused by Langendorff technique were submitted to 40 min of coronary artery occlusion followed by 60 min of reperfusion (IC). Other hearts received BZ during the first 10 min of reperfusion in absence or presence of L-NAME, NOS inhibitor. The infarct size (IS) and the post-ischemic recovery of myocardial function were measured. Oxidative/nitrosative damage were assessed by reduced glutathione (GSH) content, thiobarbituric acid reactive substances (TBARS) and 3-nitrotyrosine levels. The expression of phosphorylated forms of Akt, p38MAPK and eNOS, and the concentration of inducible nitric oxide synthase (iNOS) were also determined. Results BZ significantly decreased IS (6.2 ± 0.5% vs. 34 ± 4%), improved post-ischemic contractility, preserved GSH levels and diminished TBARS and 3-nitrotyrosine. In IC hearts, P-Akt, P-p38MAPK and P-eNOS decreased and iNOS increased. After BZ addition the levels of P-kinases and P-eNOS increased and iNOS decreased. Except for P-Akt, P-p38MAPK and iNOS, the effects of BZ were abolished by L-NAME. Conclusions Our data demonstrate that the treatment with BZ at the onset of reperfusion was effective to reduce cell death, contractile dysfunction and oxidative/nitrosative damage produced by coronary artery occlusion. These BZ-mediated beneficial actions appear mediated by eNOS/NO-dependent pathways. Highlights • Treatment with Benzolamide at reperfusion in a model of regional ischemia. • The addition of Benzolamide decreased infarct size and improved contractility. • Benzolamide preserved GSH levels and diminished TBARS and 3-nitrotyrosine. • After Benzolamide addition the levels of P-Akt, P-p38MAPK and P-eNOS increased. • The levels of iNOS decreased in presence of Benzolamide. [ABSTRACT FROM AUTHOR]

Heterocyclic amines and acetamide derivatives are known for their chemotherapeutic potential. Hence, in the present study, morpholine was taken as a principal product and novel morpholine derivatives were designed, formulated, characterized, and screened for the mechanism of inhibition of carbonic anhydrase and their anticancer potential. In addition, in vitro inhibition of hypoxia-inducible factor-1 (HIF-1) protein was also investigated. Results revealed that compounds 1c, 1d, and 1h possessed significant inhibitory activities against carbonic anhydrase with IC 50 of 8.80, 11.13, and 8.12 μM, respectively. Interestingly, the carbonic anhydrase inhibitory activity of compound 1h was comparable with that of standard acetazolamide (IC 50 7.51 μM). The compounds 1h and 1i significantly inhibited the proliferation of ovarian cancer cell line ID8 with IC 50 of 9.40, and 11.2 μM, respectively while the standard cisplatin exhibited an IC 50 8.50 μM. In addition, compounds 1c, 1b, 1h and 1i also exhibited significant inhibitory effects on HIF-1α. In conclusion, we report first time the biological potential of morpholine based compounds against ovarian cancer and HIF-1α that may serve as lead molecules for drug discovery., Competing Interests: The authors have declared no conflict of interest whatsoever., (© 2023 The Authors. Published by Elsevier Ltd.)

Hit, Lead & Candidate Discovery A series of 1 ‐ (6 ‐ methyl ‐ 2 ‐ substituted phenyl ‐ 4 ‐ thioxo ‐ 4H ‐ 1,3 ‐ oxazin ‐ 5 ‐ yl)ethanones (3a ‐ n) were synthesized by the reaction of benzoyl isothiocyanates with active methylene compound acetylacetone in the presence of triethyl amine in a one ‐ pot process. The structures of the products were elucidated by elemental analyses, FT ‐ IR, 1H NMR, 13C NMR, and mass spectroscopy. These new 1,3 ‐ oxazine derivatives were evaluated for their inhibitory activity against carbonic anhydrase II. Results for in vitro assay revealed that compound 3b having 4 ‐ methoxy phenyl moiety was the most potent inhibitor with IC50 value of 0.144   ±   0.008   μM. It exhibited higher enzyme inhibitory activity as compared to the standard acetazolamide (IC50   =   0.997   ±   0.061   μM). The compounds 3c, 3h, and 3n also displayed superior inhibitory activities compared to the rest of the synthesized oxazine derivatives. The radical scavenging activity of oxazine derivatives was also performed and it was found that compounds showed moderate antioxidant activity. Lipinski rule confirmed the therapeutic potential of the synthesized compounds. Molecular docking studies were also performed to further understand the binding affinity of these compounds with PDBID 1V9E which confirmed that the synthesized derivatives bind in the active binding site of the target protein. Based upon our results, it is proposed that compound 3b may serve as a lead structure to design more potent carbonic anhydrase inhibitors. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and biological evaluation of a library of isoindoline-1,3-dione-based oximes and benzenesulfonamide hydrazones is disclosed. The set of hydroxyiminoethyl aromatic derivatives 10–18 was designed to assess the potentiality as zinc-binder for a feebly studied functional group in the field of carbonic anhydrase (CA, EC 4.2.1.1) inhibition. Analogue phenylphthalimmides were linked to benzenesulfonamide scaffold by hydrazone spacers in the second subset of derivatives 20–28 to further investigate the application of the “tail approach” as tool to afford CA selective inhibition profiles. The compounds were assayed for the inhibition of physiologically relevant isoforms of human carbonic anhydrases (hCA, EC 4.2.1.1), the cytosolic CA I and II, and the membrane-bound CA IV and tumor-associated CA IX. The new zinc-binders, both of the oxime and sulfonamide types, showed a striking selective activity against the target hCA IX over ubiquitous hCA I and II, with diverse inhibitory ranges and ratio differing the two subsets. With CA IX being a strongly current antitumor/antimetastatic drug target, these series of compounds may be of interest for the development of new, both conventional and unconventional anticancer drugs targeting hypoxia-induced CA isoforms such as CA IX with minimum ubiquitous CAs-related side effects. [ABSTRACT FROM AUTHOR]

In the quest for novel effective carbonic anhydrase inhibitors, some sulfonamide derivatives of pyridyl-indole based chalcone were synthesized and screened in vitro for inhibitory activity against human carbonic anhydrase IX isoform. Among all the synthesized compounds (SC2 -SC11), only three compounds SC3, SC7 and SC10 were found to have better binding affinity as shown by molecular docking and fluorescence binding studies. Further, the enzyme inhibition assay and in vitro anti-tumor evaluation against MCF-7 and HepG-2 cell lines revealed that the compounds SC3, SC7 and SC10 inhibited the CA IX selectively, possessed predominant anti-proliferative potential and significantly induced apoptosis in cancerous cells. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the immunomodulatory, antiglycation and anti-ulcerative properties of Ruellia squarrosa Fenzl. Acanthaceae. Methods: Aerial parts and roots of Ruellia squarrosa were collected and extracted by maceration using dichloromethane and methanol as solvents. Luminol-enhanced chemiluminescence assay was used to evaluate immunomodulatory activity while antiglycation assay was performed by fluorescence method with rutin as standard. Anti-ulcerative activity was evaluated by enzymatic methods, namely, urease inhibition and carbonic anhydrase inhibition assays. Results: Dichloromethane extract showed immunomodulatory activity with half-maximal inhibitory concentration (IC50) of 39.48 ± 8.06 % using ibuprofen as standard and antiglycation effect (IC50 = 382.21 ± 3.43) using rutin as standard. The methanol extract of the aerial parts of the plant showed urease inhibition activity (IC50 = 130.2 ± 0.57) using thiourea as standard. The methanol extract of the aerial parts of the plant also showed carbonic anhydrase inhibition activity (IC50 = 1656.7 ± 0.08) using acetazolamide as standard. Conclusion: It was concluded from the present study that aerial and root extracts of the Ruellia squarrosa have significant immunomodulatory, antiglycation and anti-ulcerative properties. [ABSTRACT FROM AUTHOR]

Epilepsy is one of the most common neurological diseases, with between 34 and 76 per 100,000 people developing epilepsy annually. Epilepsy therapy for the past 100 years is based on the use of antiepileptic drugs (AEDs). Despite the availability of more than twenty old and new AEDs, approximately 30% of patients with epilepsy are not seizure-free with the existing medications. In addition, the clinical use of the existing AEDs is restricted by their side-effects, including the teratogenicity associated with valproic acid that restricts its use in women of child-bearing age. Thus, there is an unmet clinical need to develop new, effective AEDs. In the present study, a novel class of carbamates incorporating phenethyl or branched aliphatic chains with 6-9 carbons in their side-chain, and 4-benzenesulfonamide-carbamate moieties were synthesized and evaluated for their anticonvulsant activity, teratogenicity and carbonic anhydrase (CA) inhibition. Three of the ten newly synthesized carbamates showed anticonvulsant activity in the maximal-electroshock (MES) and 6 Hz tests in rodents. In mice, 3-methyl-2-propylpentyl(4-sulfamoylphenyl)carbamate( 1), 3-methyl-pentan-2-yl-(4-sulfamoylphenyl)carbamate ( 9) and 3-methylpentyl, (4-sulfamoylphenyl)carbamate ( 10) had ED values of 136, 31 and 14 mg/kg (MES) and 74, 53, and 80 mg/kg (6 Hz), respectively. Compound ( 10) had rat-MES-ED = 13 mg/kg and ED of 59 mg/kg at the mouse-corneal-kindling test. These potent carbamates ( 1,9,10) induced neural tube defects only at doses markedly exceeding their anticonvuslnat-ED values. None of these compounds were potent inhibitors of CA IV, but inhibited CA isoforms I, II and VII. The anticonvulsant properties of these compounds and particularly compound 10 make them potential candidates for further evaluation and development as new AEDs. [ABSTRACT FROM AUTHOR]

In this study, proton transfer salt (3) was synthesized from (E)-3-(4-sulfamoylphenylcarbamoyl)acrylic acid (1) and 1H-benzimidazole (2), which is reported in literature. Four metal complexes [Fe(II), Co(II), Ni(II) and Zn(II), (4-7)] of the salt have also been synthesized. The structure of amorphous metal complexes have been proposed by using elemantal analysis, ICP-OES, FT-IR, UV-Vis, magnetic susceptibility and molar conductivity techniques. In addition, in vitro studies have been performed to determine the inhibition effects of synthesized compounds on human erythrocyte hCA I and hCA II isoenzymes. It has been observed that synthesized compounds have affected esterase activities of hCA I and hCA II and the inhibition values of these compounds are comparable with the inhibition values of control compound acetazolamide (AAZ). [ABSTRACT FROM AUTHOR]

Carbonic anhydrase inhibitors have emerged in the past few years as an interesting candidate for the development of novel unconventional strategies. Despite their effect in tumor regression via inhibition of tumor acidification, their potential role is not yet fully elucidated. Herein, we investigated whether acetazolamide (AZ) could modulate imatinib (IM) anticancer activity, both in breast cancer cells (T47D) and in isolated tumor specimens of Ehrlich ascites carcinoma (EAC). The impact of this combination on angiogenesis was evidenced by decreasing PDGF-A expression and enhancing that of TSP-1. In the meantime, AZ significantly suppressed IM-induced attenuation of VEGF secretion in T47D cells, most probably due to NO inhibition. The combination also dramatically decreased the metastatic activity of T47D cells by mitigating the protein levels of MMP-2 and -9 and phosphorylation of p38 MAPK, while increasing the expression of TIMP-1 and -2. In addition, a strong proapoptotic effect was observed in T47D cells after combining AZ and IM in terms of increased caspase-9 and -3 activities. Interestingly, these results were confirmed by the reduction in the isolated tumor volume, MVD, Ki-67 and VEGF expression. Eventually, the study provides a new therapeutic strategy for treating cancer. [ABSTRACT FROM AUTHOR]

A series of Mannich bases having piperidine moiety were reacted with 2-mercaptoethanol, leading to 1-aryl-3-piperidine-4-yl-1-propanone hydrochlorides. The cytotoxicity and carbonic anhydrase inhibitory activities of these new compounds were evaluated. Among the compounds, only one derivative, nitro substituent bearing EU9, showed an effective cytotoxicity, although weak tumor specificity against human oral malignant versus nonmalignant cells. The compound induced apoptosis in HSC-2 oral squamous cell carcinoma cells, but not in human gingival fibroblast. Chemical modifications of this lead are thus necessary to further investigate it as a drug candidate and to obtain compounds with a better activity profile. [ABSTRACT FROM AUTHOR]

Our objective was to study the effect of dorzolamide on corneal hydration in an 18-week controlled experiment using ultrasonic pachymetry. Twenty-eight male rabbits were divided randomly into four groups. The 7 rabbits in each group received eye drops containing either 2% (w/v) dorzolamide or placebo in their right eye, or in their left eye. The 2% dorzolamide rabbits were treated every 8 h. Fellow eyes are defined as eyes which did not receive either dorzolamide or placebo. The study was blind for both the person who applied the drug and the one who performed the pachymetry. The effect of treatments is reported on the basis of the percentage of pachymetric variation compared to the measurement made before drug application. There was no significant difference (P = 0.061) in pachymetric variation between dorzolamide (-4.42 ± 11.71%) and placebo (2.48 ± 9.63%). However, there was a significant difference (P = 0.0034) in pachymetric variation between the dorzolamide fellow eyes (-7.56 ± 10.50%) and the placebo (-4.42 ± 11.71%). In conclusion, dorzolamide did not increase the corneal thickness in rabbits.

Our objective was to study the effect of dorzolamide on corneal hydration in an 18-week controlled experiment using ultrasonic pachymetry. Twenty-eight male rabbits were divided randomly into four groups. The 7 rabbits in each group received eye drops containing either 2% (w/v) dorzolamide or placebo in their right eye, or in their left eye. The 2% dorzolamide rabbits were treated every 8 h. Fellow eyes are defined as eyes which did not receive either dorzolamide or placebo. The study was blind for both the person who applied the drug and the one who performed the pachymetry. The effect of treatments is reported on the basis of the percentage of pachymetric variation compared to the measurement made before drug application. There was no significant difference (P = 0.061) in pachymetric variation between dorzolamide (-4.42 ± 11.71%) and placebo (2.48 ± 9.63%). However, there was a significant difference (P = 0.0034) in pachymetric variation between the dorzolamide fellow eyes (-7.56 ± 10.50%) and the placebo (-4.42 ± 11.71%). In conclusion, dorzolamide did not increase the corneal thickness in rabbits.

Abstract: The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51–4.06μM). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (K i: 2.88±0.86μM). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (K i: 2.51±0.34μM). [Copyright &y& Elsevier]

Abstract: Carbonic anhydrases (CAs, EC 4.2.1.1) are a group of metalloenzymes that play important roles in carbon metabolism, pH regulation, CO2 fixation in plants, ion transport etc., and are found in all eukaryotic and many microbial organisms. This family of enzymes catalyzes the interconversion of CO2 and HCO3 −. There are at least 16 different CA isoforms in the alpha structural class (α-CAs) that have been isolated in higher vertebrates, with CA isoform II (CA II) being ubiquitously abundant in all human cell types. CA inhibition has been exploited clinically for decades for various classes of diuretics and anti-glaucoma treatment. The characterization of the overexpression of CA isoform IX (CA IX) in certain tumors has raised interest in CA IX as a diagnostic marker and drug target for aggressive cancers and therefore the development of CA IX specific inhibitors. An important goal in the field of CA is to identify, rationalize, and design potential compounds that will preferentially inhibit CA IX over all other isoforms of CA. The variations in the active sites between isoforms of CA are subtle and this causes non-specific CA inhibition which leads to various side effects. In the case of CA IX inhibition, CA II along with other isoforms of CA provide off-target binding sites which is undesirable for cancer treatment. The focus of this article is on CA IX inhibition and two different structural approaches to CA isoform specific drug designing: tail approach and fragment addition approach. [Copyright &y& Elsevier]

Abstract: In this study, we present an application of EVA descriptors for a QSAR model of inhibition of carbonic anhydrase isozyme CA II by an heterogeneous set of 66 sulfonamide compounds. For each of the compounds, geometry optimization and frequency calculations have been performed using the DFT/B3LYP level of the theory in conjugated with the 6-31G* basis set. Different numbers of EVA descriptors for each structure were produced by applying various values of Gaussian kernel of a fixed standard deviation, σ (cm−1) and sampled at fixed increments of L (cm−1) during the evaluation of the descriptors based on their vibrational frequencies. The set of compounds was divided into two subsets. The first subset contained the 22 compounds that were used as the test compounds. The remaining 44 compounds were used as the training set. Several QSAR models have been developed using these calculated EVA descriptors and the carbonic anhydrase isozyme CA II inhibitory data (Ki ) of the compounds. Among the QSAR models evaluated, the one that produced the best statistical results had the parameters σ and L both equal to 5cm−1. This model produced correlation values (R 2) of 0.777 and 0.616 for the training and test sets, respectively. The results of this study showed that EVA descriptors perform well as explanatory and predictive tools for modeling the inhibition activity of carbonic anhydrase by a set of sulfonamide compounds. [Copyright &y& Elsevier]

• The sulfonamide bearing thiadiazole derivatives were synthesized as enzyme inhibitors. • Target compounds bind strongly with the target enzyme (PDBID 1V9E). • The compounds show anticancer activity through carbonic anhydrase inhibition rather than by DNA binding. A series of sulfonamide derivatives bearing 2,5-disubstituted-1,3,4-thiadiazole (5a–j) have been synthesized. Thiosemicarbazide was reacted with CS 2 to get 2-amino-5-mercapto-1,3,4-thiadiazole 1. The intermediate thiadiazole (1) was alkylated by reacting with different halides (2a–c) to afford the alkylated thiadiazoles (3a–c). The title sulfonamide bearing derivatives (5a–j) have been prepared by condensation of sulfonyl chlorides (4a–d) with thiadiazole derivatives (3a–c). The molecular docking studies of target molecules showed strong binding of compounds (5a–j) with target enzyme (PDBID 1V9E) particularly for compound 5f containing fluoro and methoxy groups. The carbonic anhydrase (CA) inhibitory activity showed derivative 5h to be the most potent (IC 50 0.60 ± 0.02 µM) as compared to acetazolamide (IC 50 0.984 ± 0.12 µM) used as standard. Free radical scavenging activity was measured using ascorbic acid as a reference. It was observed that just like CA inhibition the compound 5h showed greater free radical scavenging activity than all other target molecules. Enzyme inhibition kinetics (Lineweaver-Burk plots) showed a compound (5h) to inhibit the enzyme by mixed type of inhibition (Ki and Kiʹ values 2.91 µM and 3.88 µM, respectively). Compound 5h was further investigated that a smaller value of Ki than Ki ′ showed preferred competitive binding over non-competitive manners. The anticancer activity performed against the MCF-7 cell line showed that the compound 5h inhibits 40% cell growth at 125 µM concentration. The mechanism of anticancer potential was further investigated by DNA binding studies through electrochemical methods. The UV-Vis spectroscopy and Cyclic voltammetry results suggested that 5h was weakly bound to DNA (binding constant 30–32 M−1). It is thus proposed that anticancer activity of 5h may be through carbonic anhydrase inhibition rather than by DNA binding. Our investigations suggested the derivative 5h to serve as a lead structure in designing potentially more active carbonic anhydrase inhibitors. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose:Failure to show adequate anesthetization during the intracarotid amobarbital procedure (IAP or“Wada test”) is a rare complication. After an unusually high rate of recent anesthetization failures, we sought to determine the frequency of reduced anesthetization and any common factors underlying these failures.Methods:We reviewed the records of all patients who underwent IAP tests through the UCLA Seizure Disorder Center between September 1999 and May 2002. Age, date, epileptogenic focus, radiologist, and current medications were all considered.Results:Of a total of 56 patients who underwent our intracarotid amobarbital examination, 11 (19.6%) showed either very rapid recovery (≤1 min) or anesthetization failure. Of these, 10 (91%) of 11 were taking a medication with some carbonic anhydrase–inhibiting (CAI) properties (topiramate (TPM), n= 7; zonisamide (ZNS), n= 2; hydrochlorothiazide and furosemide, n= 1 each). The only patient of 40 (2.5%) who was not taking any CAI drugs and showed an early IAP recovery (55 s) had recently discontinued TPM. IAPs performed on patients after weaning from TPM showed a correlation between length of drug discontinuation and duration of anesthesia effect.Conclusions:Our data strongly suggest that recent failures of anesthetization during the IAP are associated with a possible interaction between amobarbital and medications possessing CAI properties. We suggest that the IAP be performed only after≥8 weeks after discontinuation of such medications. [ABSTRACT FROM AUTHOR]