Novel thiazolotriazole and triazolothiadiazine scaffolds as selective tumor associated carbonic anhydrase inhibitors endowed with cathepsin B inhibition

The present research focused on the tail-approach synthesis of novel extended thiazolotriazoles (8a-8j) and triazolothiadiazines (11a-11j) including aminotriazole intermediate 10. After successful synthesis, all the compounds were evaluated for their inhibition potential against cytosolic isoforms of human carbonic anhydrase (hCA I, II), tumor-linked transmembrane isoforms (hCA IX, XII), and cathepsin B. As per the inhibition data, the newly synthesized compounds showed poor inhibition against hCA I. Many of the compounds showed effective inhibition toward hCA IX and/or XII in low nanomolar concentration. Despite the strong to moderate inhibition of hCA II by these compounds, more than half of them demonstrated better inhibition against hCA IX and/or XII, comparatively. Further, insights of CA inhibition data of these extended analogs and their comparison with earlier reported thiazolotriazole and triazolothiadiazine derivatives might help in the rational design of novel potent and selective hCA IX and XII inhibitors. The novel compounds were also found to possess anti-cathepsin B potential at a low concentration of 10-7 M. Broadly, compounds of series 11a-11j presented more effective inhibition against cathepsin B than their counterparts in series 8a-8j. Moreover, these in vitro results with respect to cathepsin B inhibition were also supported by the in silico insights obtained via molecular modeling studies.

Benzenesulfonamides functionalized with triazolyl-linked pyrazoles possess dual cathepsin B and carbonic anhydrase inhibitory action

The design and synthesis of a library of 21 novel benzenesulfonamide-bearing 3-functionalized pyrazole-linked 1,2,3-triazole derivatives as dual inhibitors of cathepsin B and carbonic anhydrase enzymes are reported. The target 1,2,3-triazole-linked pyrazolic esters (16) were synthesized by the condensation of 1,2,3-triazolic diketo esters with 4-hydrazinobenzenesulfonamide hydrochloride, and these were further converted into the corresponding carboxylic acid (17) and carboxamide (18) analogs. The synthesized compounds were assayed in vitro for their inhibition potential against human carbonic anhydrase (hCA) isoforms I, II, IX, and XII. They were found to be potent inhibitors at the low nanomolar level against the cancer-related hCA IX and XII and to be selective towards the cytosolic isoform hCA I. The physiologically important isoform hCA II was potently inhibited by all the newly synthesized compounds showing KI values ranging between 0.8 and 561.5 nM. The ester derivative 16c having 4-fluorophenyl (KI = 5.2 nM) was the most potent inhibitor of hCA IX, and carboxamide derivative 18b (KI = 2.2 nM) having 4-methyl substituted phenyl was the most potent inhibitor of hCA XII. The newly synthesized compounds exhibited potent cathepsin B inhibition at 10-7 M concentration. In general, the carboxamide derivatives (18) showed higher % inhibition as compared with the corresponding ester derivatives (16) and carboxylic acid derivatives (17) for cathepsin B. The interactions of the target compounds with the active sites of cathepsin B and CA were studied through molecular docking studies. Further, the in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) and drug-likeness properties of the target compounds were also studied.

Chalcone-based benzenesulfonamides as potent and selective inhibitors for human carbonic anhydrase II: Design, synthesis, in vitro, and in silico studies

Sulfonamides are promising classical carbonic anhydrase (CA; EC 4.2.1.1) inhibitors, being used for several medical purposes such as diuretics, anticonvulsants, topically acting antiglaucoma agents, for antiobesity and anticancer therapies. Herein, a series of chalcone-based benzenesulfonamides (3a‒m) was synthesized and assessed for its inhibitory activity against a panel of four human carbonic anhydrases (hCA isoforms I, II, IX, and XII). Most compounds displayed single- to double-digit nanomolar inhibition constants (Kis), with some derivatives being more potent and/or selective than the standard drug acetazolamide (AAZ). Among the synthesized compounds, 3g compound demonstrated the highest inhibitory activity against the hCA II isoform (Ki = 2.5 nM) with 30-, 9-, and 11-fold selectivity for hCA II over the I, IX, and XII isoforms, respectively. Structure-activity relationships for different substitution patterns were analyzed. Additionally, a molecular docking study showed that compound 3g bound to hCA II by coordinating with the zinc ion through the deprotonated benzenesulfonamide moiety, in addition to a hydrogen bond formed between an oxygen of the sulfonamide moiety and Thr199. Moreover, the chalcone core participated in van der Waals interactions with some active site residues, such as Ile91, Val121, and Leu198. Consequently, this report introduces a successful approach toward identifying compound 3g as a highly potent and selective chalcone-based benzenesulfonamide inhibitor of hCA II worthy of further investigation.

Proximal versus distal diuretics in congestive heart failure

Volume overload represents a hallmark clinical feature linked to the development and progression of heart failure (HF). Alleviating signs and symptoms of volume overload represents a foundational HF treatment target that is achieved using loop diuretics in the acute and chronic setting. Recent work has provided evidence to support guideline-directed medical therapies, such as sodium glucose cotransporter 2 (SGLT2) inhibitors and mineralocorticoid receptor (MR) antagonists, as important adjunct diuretics that may act synergistically when used with background loop diuretics in people with chronic HF. Furthermore, there is growing interest in understanding the role of SGLT2 inhibitors, carbonic anhydrase inhibitors, thiazide diuretics, and MR antagonists in treating volume overload in patients hospitalized for acute HF, particularly in the setting of loop diuretic resistance. Thus, the current review demonstrates that: (i) SGLT2 inhibitors and MR antagonists confer long-term cardioprotection in chronic HF patients but it is unclear whether natriuresis or diuresis represents the primary mechanisms for this benefit, (ii) SGLT2 inhibitors, carbonic anhydrase inhibitors, and thiazide diuretics increase natriuresis in the acute HF setting, but implications on long-term outcomes remain unclear and warrants further investigation, and (iii) a multi-nephron segment approach, using agents that act on distinct segments of the nephron, potentiate diuresis to alleviate signs and symptoms of volume overload in acute HF.

Predictors of Headaches and Quality of Life in Women with Ophthalmologically Resolved Idiopathic Intracranial Hypertension

Background/objectives: The aim of this study was to evaluate the long-term outcomes of a cohort of ophthalmologically resolved female idiopathic intracranial hypertension (IIH) patients. Methods: Our cross-sectional study included adult females with at least 6 months of ophthalmologically resolved IIH. Patients with papilledema or who underwent IIH-targeted surgical intervention were excluded. Participants completed a questionnaire consisting of medical information, the Migraine Disability Assessment Scale (MIDAS) and the Headache Impact Test (HIT-6). Electronic medical records and the results of imaging upon diagnosis were retrospectively reviewed. Results: One-hundred-and-four participants (mean age 35.5 ± 11.9 years) were included (7.85 ± 7 years post-IIH diagnosis). Patients with moderate-severe disability according to the MIDAS scale (n = 68, 65.4%) were younger (32.4 ± 8.9 vs. 41.5 ± 14.4 year-old, p < 0.001), had a shorter time interval from IIH diagnosis (5.9 ± 5.3 vs. 11.7 ± 8.5 years, p < 0.001), and had lower FARB scores (indicating a more narrowed transverse-sigmoid junction; 1.28 ± 1.82 vs. 2.47 ± 2.3, p = 0.02) in comparison to patients with low-mild disability scores. In multivariate analysis, a lower FARB score (OR 1.28, 95% CI 0.89-1.75, p = 0.12) and younger age (OR 1.09, 95% CI 0.98-1.19, p = 0.13) showed a trend toward an association with a moderate-severe MIDAS score. Moreover, in the sub-analysis of patients with a moderate-severe MIDAS scale score, the 10 patients with the highest MIDAS scores had a low FARB score (1.6 ± 1.1 vs. 2.7 ± 2.4, p = 0.041). Conclusions: High numbers of patients with ophthalmologically resolved IIH continue to suffer from related symptoms. Symptoms may be associated with the length of time from the diagnosis of IIH and a lower FARB score.

The effect of systemic acetazolamide administration on intraocular pressure in healthy horses-A preliminary study

OBJECTIVES

In equine glaucoma, topical treatment with carbonic anhydrase inhibitors (CAIs) is recommended. Oral acetazolamide, a systemic CAI, is used in horses with hyperkalemic periodic paralysis. Information regarding its effect on equine intraocular pressure (IOP) is scarce. The aim of the study was to determine the effect of oral acetazolamide treatment on IOP in horses, in a case-control study.

ANIMALS

Ten healthy horses.

PROCEDURES

Horses were treated with oral acetazolamide (4.4 mg/kg) BID for 1 week. Serum acetazolamide concentrations were determined by liquid chromatography/tandem mass spectrometry, and IOP were measured before treatment, daily during treatment, and at 48 and 72 h after treatment.

RESULTS

Acetazolamide serum levels reached steady state at 72 h after the first oral dose. In a mixed effect model logistic regression, there was a significant decrease in IOP on the third treatment day, of 2.4 mmHg (p = .012) and 2.7 mmHg (p = .006) in the left (OS) and right eye (OD), respectively. On the seventh day, there was a decrease in 2.5 mmHg (p = .008) and 2.7 mmHg (p = .007) OS and OD, respectively. A significant increase occurred 48 h following treatment discontinuation (3.6 mmHg, p < .001 and 3.5 mmHg, p < .001 OS and OD, respectively). The area under the concentration versus time curve (AUC(0-10h)) was 1.1 ± 0.5 μg/mL*h, mean residence time 6.7 ± 4.3 h, peak plasma concentration (Cmax) 0.4 ± 0.4 μg/mL and time to reach Cmax 1.8 h. There was a significant increase in serum concentrations 1, 2, 48, 72, and 156 h following the first drug administration (p < .05).

CONCLUSIONS

Further studies are required to determine whether acetazolamide is a potential treatment for equine glaucoma.

DEXAMETHASONE IMPLANT VERSUS TOPICAL CARBONIC ANHYDRASE INHIBITORS IN PATIENTS WITH BILATERAL RETINITIS PIGMENTOSA-RELATED CYSTOID MACULAR EDEMA: A Prospective, Paired-Eye Pilot Study

PURPOSE

To compare within-subject efficacy and safety of intravitreal dexamethasone implant and topical carbonic anhydrase inhibitors in the treatment of retinitis pigmentosa-related cystoid macular edema.

METHODS

Patients with bilateral retinitis pigmentosa-related cystoid macular edema were treated with intravitreal dexamethasone implant in one eye and topical carbonic anhydrase inhibitors in the contralateral eye. The primary endpoint was a change in central macular thickness. Secondary endpoints were changes in best-corrected visual acuity and microperimetric central retinal sensitivity. Intraocular pressure and other ocular complications were evaluated for safety assessment.

RESULTS

Nine patients were recruited for this 12-month follow-up study. Central macular thickness was significantly lower in intravitreal dexamethasone implant-treated eyes than in topical carbonic anhydrase inhibitors-treated eyes at Months 1 and 7, whereas mean best-corrected visual acuity was better in eyes treated with topical carbonic anhydrase inhibitors at Month 12 (borderline significant P = 0.0510). There was no difference in microperimetric sensitivity between the two treatments. Three patients developed ocular hypertension after intravitreal dexamethasone implant. Intravitreal dexamethasone implant showed an effect on the contralateral eye in five of nine patients.

CONCLUSION

Intravitreal dexamethasone implant was more effective than topical carbonic anhydrase inhibitors in reducing retinitis pigmentosa-related cystoid macular edema 1 month after treatment. Corticosteroids can play a key role in the management of retinitis pigmentosa-related cystoid macular edema; however, their routes, timing, and modes of administration should be further explored.

Novel 1,2,4-triazoles as selective carbonic anhydrase inhibitors showing ancillary anticathepsin B activity

Background: Exploration of the multi-target approach considering both human carbonic anhydrase (hCA) IX and XII and cathepsin B is a promising strategy to target cancer. Methodology & Results: 22 novel 1,2,4-triazole derivatives were synthesized and evaluated for their inhibition efficacy against hCA I, II, IX, XII isoforms and cathepsin B. The compounds demonstrated effective inhibition against hCA IX and/or XII isoforms with considerable selectivity over off-target hCA I/II. All compounds presented significant anticathepsin B activities at a low concentration of 10-7 M and in vitro results were also supported by the molecular modeling studies. Conclusion: Insights of present study can be utilized in the rational design of effective and selective hCA IX and XII inhibitors capable of inhibiting cathepsin B.

Synthesis of 4-sulfamoyl phenyl diazocarboxylic acid derivatives as novel non-classical inhibitors of human carbonic anhydrase II activity: an in vitro study

The first class of carbonic anhydrase inhibitors (CAIs) discovered was sulfonamides, but their clinical use is limited due to side effects caused by their inhibition of multiple CA isoforms. To overcome this, researchers have focused on developing isoform-selective CAIs. This study involved the synthesis and characterization of novel carboxylic acid/sulfonamide derivatives. We investigated the interaction between these compounds and the human carbonic anhydrase II (hCA II) isoform using spectroscopic and computational methods. The synthesized compounds were evaluated based on their IC50, Kd and Ki values, and it was found that the inhibitory potency and binding affinity of the compounds increased with the number of carboxylic acids zinc binding groups. Specifically, the compound C4, with three carboxylic acid groups, showed the strongest inhibitory potency. Fluorescence measurements revealed that all compounds quenched the intrinsic fluorescence of hCA II through a dynamic quenching process, and each compound had one binding site in the hCA II structure. Thermodynamic analysis indicated hydrogen bonds and van der Waals interactions played key roles in the binding of these compounds to hCA II. Docking studies showed that the carboxylic acid groups directly attached to the zinc ion in the active site, displacing water/hydroxide ions and causing steric hindrance. Overall, the strengthening of inhibitory activity and the binding power of these carboxylic acid derivatives for the hCA II makes these compounds interesting for designing novel hCA II inhibitors.Communicated by Ramaswamy H. Sarma.

Design and Synthesis of Pyrazole Carboxamide Derivatives as Selective Cholinesterase and Carbonic Anhydrase Inhibitors: Molecular Docking and Biological Evaluation

The present study focused on the synthesis and characterization of novel pyrazole carboxamide derivatives (SA1-12). The inhibitory effect of the compounds on cholinesterases (ChEs; AChE and BChE) and carbonic anhydrases (hCAs; hCA I and hCA II) isoenzymes were screened as in vitro. These series compounds have been identified as potential inhibitors with a KI values in the range of 10.69±1.27-70.87±8.11 nM for hCA I, 20.01±3.48-56.63±6.41 nM for hCA II, 6.60±0.62-14.15±1.09 nM for acetylcholinesterase (AChE) and 54.87±7.76-137.20 ±9.61 nM for butyrylcholinesterase (BChE). These compounds have a more effective inhibition effect when compared to the reference compounds. In addition, the potential binding positions of the compounds with high affinity for ChE and hCAs were demonstrated by in silico methods. The results of in silico and in vitro studies support each other. As a result of the present study, the compounds with high inhibitory activity for metabolic enzymes, such as ChE and hCA were designed. The compounds may be potential alternative agents used as selective ChE and hCA inhibitors in the treatment of Alzheimer's disease and glaucoma.

Morphological and functional parameters in X-linked retinoschisis patients-A multicentre retrospective cohort study

Introduction

X-linked retinoschisis (XLRS) is a potential target for gene supplementation approaches. To establish potential structural and functional endpoints for clinical trials, a comprehensive understanding of the inter-eye symmetry, relationship between structural and functional parameters, and disease progression is vital.

Methods

In this retrospective multicentre study, 118 eyes of 59 XLRS patients with RS1 mutations were assessed. Information from center databases included: RS1 variant; age at presentation; best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular volume (MV) at presentation and at the last follow up; full-field electroretinogram (ERG) findings; presence of peripheral retinoschisis and complications (vitreous hemorrhage, retinal detachment); treatment with systemic or topical carbonic anhydrase inhibitors (CAI).

Results

Inter-eye symmetry revealed strong correlation in CRT (r = 0.77; p < 0.0001) and moderate correlations in MV (r = 0.51, p < 0.0001) and BCVA (r = 0.49; p < 0.0001). Weak or no correlations were observed between BCVA and structural parameters (CRT, MV). Peripheral retinoschisis was observed in 40 (68%), retinal detachment in 9 (15%), and vitreous hemorrhage in 5 (8%) patients, respectively. Longitudinal examinations (mean, 4.3 years) showed no BCVA changes; however, a reduction of the CRT (p = 0.02), and MV (p = 0.01) was observed. Oral and/or topical CAI treatment did not significantly alter the CRT (p = 0.34).

Discussion

The XLRS phenotype demonstrates a strong CRT symmetry between the eyes within individual patients and stable BCVA over several years. BCVA exhibits a weak correlation with the morphological parameters of retinal thickness (CRT MV). In our cohort, longitudinal functional changes were not significant, likely attributed to the short average follow-up period. Furthermore, CAI treatment didn't influence both morphological and functional outcomes.

Carbonic anhydrase inhibitors limit complications in X-linked retinoschisis

Purpose

Carbonic anhydrase inhibitors (CAIs) reduce macular schisis in patients with X-linked retinoschisis (XLRS). The purpose of this study was to determine if CAIs reduce the incidence of complications from XLRS, including macular atrophy, retinal tears, and retinal detachment (RD), the most common causes of vision loss in patients with XLRS.

Methods

For this retrospective interventional case series, a chart review of patients examined at Cincinnati Children's Hospital Medical Center [CCHMC] and Cincinnati Eye Institute [CEI] between 1/1/2015 and 1/16/2023 was performed. Male patients were included based on genetically-confirmed RS1 or typical clinical presentation with known family history of XLRS with at least two follow-up visits.

Results

Twenty-eight patients (56 eyes) with XLRS were included. There were 10 RS1 variants among the 21 genotyped patients. Median age at clinical diagnosis was 10.4 years old (range: 0.4-55.7 years) with median follow-up time of 4.7 years (range: 0.2-38.3 years). Median presenting Snellen visual acuity was 20/60 (logMAR 0.48, range: 0.18-3). In 26 eyes of 15 patients treated with CAIs, median CST pre-treatment was 416 microns (range: 198-701 microns), and median percentage decrease in CST on treatment was 21.8% (range: 0-74.5%) from highest pre-treatment CST. Reduction in CST with CAI use was statistically significant (p = 0.02), but not logMAR VA (p = 0.64). There was no significant difference in CST between patients treated with topical vs. oral CAI (p = 0.95) or between patients with partial or complete CAI adherence (p = 0.60). Ten eyes of seven patients had an RD requiring surgical intervention. No treated eyes developed new macular atrophy, peripheral retinoschisis, retinal tears, or RD; two eyes on topical CAIs had spontaneous resolution of bullous peripheral retinoschisis.

Conclusion

During the follow-up period, patients taking CAIs reduced macular schisis and did not experience new complications of macular atrophy, retinal tears, or RD. This is a relatively large cohort with long-term follow-up periods for patients with XLRS. Reduced macular schisis may not require perfect adherence with CAIs. A large, prospective, randomized, controlled clinical trial is needed to determine the potential of CAIs to improve visual function, reduce retinoschisis, and prevent RD.

Potent inhibitors of tumor associated carbonic anhydrases endowed with cathepsin B inhibition

Twenty-one novel extended analogs of acetazolamide were synthesized and screened in vitro for their inhibition efficacy against human carbonic anhydrase (hCA) isoforms I, II, IX, XII, and cathepsin B. The majority of the compounds were found to be effective inhibitors of tumor-associated hCA IX and XII, and poor inhibitors of cytosolic hCA I. Despite the strong to moderate inhibition potential possessed by these compounds toward another cytosolic isoform hCA II, some of them demonstrated better potency against hCA IX and/or XII isoforms as compared to hCA II. Four compounds (11f, 11g, 12c, and 12g) effectively inhibited hCA IX and/or XII isoforms with considerable selectivity over the off-targets hCA I and II. Interestingly, five compounds, including 11f, 11g, 12c, 12d, and 12g, inhibited hCA IX even better than the clinically used acetazolamide. Some of the novel synthesized compounds exhibited higher anti-cathepsin B potential than acetazolamide, with % inhibition of around 50%, at a concentration of 10-7  M. Further, two compounds (12g and 12c) that showed effective and selective inhibition activity profiles against hCA IX and XII were additionally found to be effective inhibitors of cathepsin B.

FDA-approved carbonic anhydrase inhibitors reduce amyloid β pathology and improve cognition, by ameliorating cerebrovascular health and glial fitness

INTRODUCTION

Cerebrovascular pathology is an early and causal hallmark of Alzheimer's disease (AD), in need of effective therapies.

METHODS

Based on the success of our previous in vitro studies, we tested for the first time in a model of AD and cerebral amyloid angiopathy (CAA), the carbonic anhydrase inhibitors (CAIs) methazolamide and acetazolamide, Food and Drug Administration-approved against glaucoma and high-altitude sickness.

RESULTS

Both CAIs reduced cerebral, vascular, and glial amyloid beta (Aβ) accumulation and caspase activation, diminished gliosis, and ameliorated cognition in TgSwDI mice. The CAIs also improved microvascular fitness and induced protective glial pro-clearance pathways, resulting in the reduction of Aβ deposition. Notably, we unveiled that the mitochondrial carbonic anhydrase-VB (CA-VB) is upregulated in TgSwDI brains, CAA and AD+CAA human subjects, and in endothelial cells upon Aβ treatment. Strikingly, CA-VB silencing specifically reduces Aβ-mediated endothelial apoptosis.

DISCUSSION

This work substantiates the potential application of CAIs in clinical trials for AD and CAA.

A Drug Utilization Study of Anti-glaucoma Drugs in a Tertiary Care Hospital

BACKGROUND AND OBJECTIVES

Today, branded medications and polytherapy are frequently prescribed for glaucoma, even without giving the patient the proper instructions. Hence, the safety, effectiveness, cost, and patient compliance of glaucoma medication must be weighed, and the anti-glaucoma medicine usage must be studied. Analysis of glaucoma patients' prescription usage was the objective of this study.

MATERIAL AND METHODS

Between January 2021 and February 2022, this prospective and observational study was carried out at Andhra Medical College in Vishakhapatnam. One hundred prescriptions of those with primary open-angle and angle closure glaucoma were assessed. Age and gender-based subgroup analyses were conducted. R software (version 4.2.1) (The R Foundation for Statistical Computing, Vienna, Austria) was leveraged for data analysis.

RESULTS

Out of 146 examined prescriptions, 100 (69%) were deemed suitable for analysis. Participants' mean age was 54.2 ± 10.8 years. Sixty-two were over 50 years old, and 36 were men. The mean intraocular pressure was 25.4 ± 1.7 mm of Hg. Per prescription, there were about 1.75 anti-glaucoma drugs. Fixed-dose combinations (FDC) were found in 43 prescriptions. Generic medications and patient instructions prevailed in most prescriptions (78%) and (84%). Timolol was used in each FDC with brimonidine, dorzolamide, or bimatoprost.

CONCLUSION

The most often prescribed anti-glaucoma drug, timolol, was also identified as an essential component of the FDC. Doctors must prescribe generic medications with detailed directions for the patients.

Ocular surface disease: a known yet overlooked side effect of topical glaucoma therapy

Ocular surface disease (OSD), a disorder affecting the lacrimal and meibomian glands and the corneal and conjunctival epithelium, is a well-known complication of topical glaucoma therapy. OSD can present as a new or pre-existing condition that virtually any anti-glaucoma formulation can exacerbate. As such, both glaucoma and OSD frequently coexist. Typical OSD symptoms include ocular discomfort, redness, burning, and dryness, whereas signs include periorbital and eyelid skin pigmentation, conjunctival scarring, and superficial punctate keratitis. Pressure-lowering eyedrops can cause toxic, allergic, and inflammatory reactions on the ocular surface. The latter can result from either preservatives or direct toxicity from the active molecule. Although usually mild, OSD can cause significant symptoms that lead to poor quality of life, decreased compliance to therapy, glaucoma progression, and worse visual outcomes. Given the chronic nature of glaucoma, lack of curative therapy, and subsequent lifelong treatment, addressing OSD is necessary. This manuscript aims to provide an up-to-date overview of OSD's signs, symptoms, and pathogenic mechanisms from glaucoma therapy toxicity.

Pharmacological Properties of Sulfonamide Derivatives, New Inhibitors of Carbonic Anhydrase

Selective blocking of individual isoforms of carbonic anhydrase (CA) is now one of the main directions in the development of its inhibitors. The new 1,2,4-oxadiazole-containing sulfonamides B12 and B13 predominantly block CA II and CA IX. The study of acute toxicity of B12 and B13 showed their safety. Substance B13 caused a relatively short-term, but rapid (within 30 min) decrease in the intraocular pressure in rabbits, which indicates the promise of its use for the emergency decrease in the intraocular pressure in medical practice. Analysis of the effects of sulfonamides on the functions of CNS showed that compound B12 probably exhibit tranquilizing activity; B13 is promising for the creation of drugs that have an antidepressant effect and at the same time increase the mental and physical performance.

Synthesis, Biological Activity Evaluation and Molecular Docking of Imidazole Derivatives Possessing Hydrazone Moiety

In an attempt to identify potential active anticancer agents with low cytotoxic properties and CA inhibitors, a new series of hybrid compounds incorporating imidazole ring and hydrazone moiety as part of their structure were synthesized by aza-Michael addition reaction followed by intramolecular cyclization. The structure of synthesized compounds was elucidated using various spectral techniques. Synthesized compounds were evaluated for their in vitro anticancer (prostate cell lines; PC3) and CA inhibitory (hCA I and hCA II) activity. Among them, some compound displayed remarkable anticancer activity and CA inhibitory activity with Ki values in range of 17.53±7.19-150.50±68.87 nM against cytosolic hCA I isoform associated with epilepsy, and 28.82±14.26-153.27±55.80 nM against dominant cytosolic hCA II isoforms associated with glaucoma. Furthermore, the theoretical parameters of the bioactive molecules were calculated to establish their drug-likeness qualities. The proteins used for the calculations are prostate cancer protein (PDB ID: 3RUK and 6XXP). ADME/T analysis was carried out to examine the drug properties of the studied molecules.

Newer, Older, and Alternative Agents for the Eradication of Helicobacter pylori Infection: A Narrative Review

Although discovered 40 years ago, Helicobacter pylori infection is still raising diagnostic and therapeutic problems today. The infection is currently managed based on statements in several guidelines, but implementing them in practice is a long process. Increasing antibiotic resistance and weak compliance of the patients limit the efficacy of eradication regimens, leaving much room for improvement. Third-generation proton pump inhibitors have added little to the results of the first two generations. Potassium-competitive acid blockers have a stronger and longer inhibitory action of acid secretion, increasing the intragastric pH. They obtained superior results in eradication when compared to proton pump inhibitors. Instead of innovative antibiotics, derivatives of existing antimicrobials were developed; some new fluoroquinolones and nitazoxanide seem promising in practice, but they are not recommended by the guidelines. Carbonic anhydrase inhibitors have both anti-secretory and bactericidal effects, and some researchers are expecting their revival in the treatment of infection. Capsules containing components of the eradication regimens have obtained excellent results, but are of limited availability. Probiotics, if containing bacteria with anti-Helicobacter pylori activity, may be useful, increasing the rates of eradication and lowering the prevalence and severity of the side effects.

Evaluation of 1,3,4-Thiadiazole Carbonic Anhydrase Inhibitors for Gut Decolonization of Vancomycin-Resistant Enterococci

Vancomycin-resistant enterococci (VRE), Enterococcus faecium and Enterococcus faecalis, are high-priority drug-resistant pathogens in need of new therapeutic approaches. VRE originate in the gastrointestinal tract of carriers and can lead to more problematic downstream infections in the healthcare setting. Having a carrier of VRE admitted into a healthcare setting increases the risk to other patients for acquiring an infection. One strategy to eliminate the downstream infections is decolonization of VRE from carriers. Here, we report the activity of a set of carbonic anhydrase inhibitors in the in vivo VRE gastrointestinal decolonization mouse model. The molecules encompass a range of antimicrobial potency and intestinal permeability, and these factors were shown to influence the in vivo efficacy for VRE gut decolonization. Overall, carbonic anhydrase inhibitors exhibited superior VRE decolonization efficacy compared to the current drug of choice, linezolid.

Five-Membered Heterocyclic Sulfonamides as Carbonic Anhydrase Inhibitors

The development of heterocyclic derivatives has progressed considerably over the past decades, and many new carbonic anhydrase inhibitors (CAIs) fall into this field. In particular, five-membered heterocyclic sulfonamides have been generally shown to be more effective inhibitors compared to six-membered rings ones. Despite the importance of oxygen and nitrogen five-membered heterocyclic aromatic rings in medicinal chemistry, the installation of sulfonamide moiety on such heterocycles has not received much attention. On the other hand, 1,3,4-thiadiazole/thiadiazoline ring-bearing sulfonamides are the scaffolds which have been widely used in a variety of pharmaceutically important CAIs such as acetazolamide, metazolamide and their many derivatives obtained by using the tail approach. Here, we reviewed the field focusing on the diverse biological activities of these CAIs, such as antiglaucoma, antiepileptic, antitumor and antiinfective properties. This review highlights developments involving five-membered heterocyclic sulfonamides over the last years, with a focus on their pharmacological/clinical applications.

Pyrazole/pyrazoline as an excellent pharmacophore in the design of carbonic anhydrase inhibitors (2018-2022)

Carbonic anhydrase (CA) is a metalloenzyme that catalyzes the interconversion between carbon dioxide and water and dissociated ions of carbonic acid. In addition, CA performs various other functions in animals and plants, depending on the part of the living being. CAs have been found in almost all organisms. Besides, CAs are associated with several diseases, such as glaucoma, obesity, epilepsy, cancer, and so on. CAs are also involved in tumor cell growth and angiogenesis. Thus, inhibition of CA may be an attractive way of control of such diseases. Hence, CA inhibitors have been designed and developed to cure CA-associated diseases. Some examples of approved CA inhibitors are dorzolamide, methazolamide, brinzolamide, and dichlorphenamide. Furthermore, various heterocyclic scaffolds were utilized for the design of CA inhibitors. Among those, pyrazole/pyrazoline derivatives have exhibited greater potency toward CA inhibition. Hence, research that took place in the field of drug design and discovery of CA inhibition has been systematically reviewed and collated. Alongside, the structure-activity relationship has been described, followed by a description of the most potent molecules and their structural features.

The Impact of Acetazolamide and Methazolamide on Exercise Performance in Normoxia and Hypoxia

Doherty, Connor J., Jou-Chung Chang, Benjamin P. Thompson, Erik R. Swenson, Glen E. Foster, and Paolo B. Dominelli. The impact of acetazolamide and methazolamide on exercise performance in normoxia and hypoxia. High Alt Med Biol. 24:7-18, 2023.-Carbonic anhydrase (CA) inhibitors are commonly prescribed for acute mountain sickness (AMS). In this review, we sought to examine how two CA inhibitors, acetazolamide (AZ) and methazolamide (MZ), affect exercise performance in normoxia and hypoxia. First, we briefly describe the role of CA inhibition in facilitating the increase in ventilation and arterial oxygenation in preventing and treating AMS. Next, we detail how AZ affects exercise performance in normoxia and hypoxia and this is followed by a discussion on MZ. We emphasize that the overarching focus of the review is how the two drugs potentially affect exercise performance, rather than their ability to prevent/treat AMS per se, their interrelationship will be discussed. Overall, we suggest that AZ hinders exercise performance in normoxia, but may be beneficial in hypoxia. Based upon head-to-head studies of AZ and MZ in humans on diaphragmatic and locomotor strength in normoxia, MZ may be a better CA inhibitor when exercise performance is crucial at high altitude.

A Combined in Silico and Structural Study Opens New Perspectives on Aliphatic Sulfonamides, a Still Poorly Investigated Class of CA Inhibitors

Aliphatic sulfonamides are an interesting class of carbonic anhydrase inhibitors (CAIs) proven to be effective for several carbonic anhydrase (CA) isoforms involved in pathologic states. Here we report the crystallographic structures of hCA II in complex with two aliphatic sulfonamides incorporating coumarin rings, which showed a good inhibition and selectivity for this isoform. Although these two molecules have a very similar chemical structure, differing only in the substitution of the two aliphatic hydrogen atoms with two fluorine atoms, they adopt a significantly different binding mode within the enzyme active site. Theoretical binding free energy calculations, performed to rationalize these data, showed that a delicate balance of electrostatic and steric effects modulate the protein-ligand interactions. Data presented here can be fruitfully used for the rational design of novel and effective isozyme-specific inhibitor molecules.

Synthesis, Biological and In Silico Studies of Griseofulvin and Usnic Acid Sulfonamide Derivatives as Fungal, Bacterial and Human Carbonic Anhydrase Inhibitors

Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the essential reaction of CO₂ hydration in all living organisms, being actively involved in the regulation of a plethora of patho-/physiological conditions. A series of griseofulvin and usnic acid sulfonamides were synthesized and tested as possible CA inhibitors. Since β- and γ- classes are expressed in microorganisms in addition to the α- class, showing substantial structural differences to the human isoforms they are also interesting as new antiinfective targets with a different mechanism of action for fighting the emerging problem of extensive drug resistance afflicting most countries worldwide. Griseofulvin and usnic acid sulfonamides were synthesized using methods of organic chemistry. Their inhibitory activity, assessed against the cytosolic human isoforms hCA I and hCA II, the transmembrane hCA IX as well as β- and γ-CAs from different bacterial and fungal strains, was evaluated by a stopped-flow CO₂ hydrase assay. Several of the investigated derivatives showed interesting inhibition activity towards the cytosolic associate isoforms hCA I and hCA II, as well as the three γ-CAs and Malassezia globosa (MgCA) enzyme. Six compounds (1b-1d, 1h, 1i and 1j) were more potent than AAZ against hCA I while five (1d, 1h, 1i, 1j and 4a) showed better activity than AAZ against the hCA II isoform. Moreover, all compounds appeared to be very potent against MgCA with a Ki lower than that of the reference drug. Furthermore, computational procedures were used to investigate the binding mode of this class of compounds within the active site of human CAs.