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Copyright of Giornale Italiano di Medicina del Lavoro ed Ergonomia is the property of Giornale Italiano di Medicina del Lavoro ed Ergonomia Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel class of compounds designed to hit two anti-tumour targets, G-quadruplex structures and human carbonic anhydrases (hCAs) IX and XII is proposed. The induction/stabilisation of G-quadruplex structures by small molecules has emerged as an anticancer strategy, disrupting telomere maintenance and reducing oncogene expression. hCAs IX and XII are well-established anti-tumour targets, upregulated in many hypoxic tumours and contributing to metastasis. The ligands reported feature a berberine G-quadruplex stabiliser scaffold connected to a moiety inhibiting hCAs IX and XII. In vitro experiments showed that our compounds selectively stabilise G-quadruplex structures and inhibit hCAs IX and XII. The crystal structure of a telomeric G-quadruplex in complex with one of these ligands was obtained, shedding light on the ligand/target interaction mode. The most promising ligands showed significant cytotoxicity against CA IX-positive HeLa cancer cells in hypoxia, and the ability to stabilise G-quadruplexes within tumour cells.

We describe here the design and antitumor evaluation of benzofuroxan-based nitric oxide (NO)-donor hybrid derivatives targeting human carbonic anhydrases (hCAs) IX and XII. The most effective compounds, 27 and 28 , demonstrated potent dual action, exhibiting low nanomolar inhibition constants against hCA IX and significant NO release. Notably, compound 27 showed significant antiproliferative effects against various cancer cell lines, particularly renal carcinoma A-498 cells. In these cells, it significantly reduced the expression of CA IX and iron-regulatory proteins, inducing apoptosis via mitochondrial caspase activity and ferroptosis pathways, as evidenced by increases in ROS, nitrite, and down-regulated expression of ferritin-encoding genes. In three-dimensional tumor models, compound 27 effectively reduced spheroid size and viability. In vivo toxicity studies in mice indicated that the compounds were well-tolerated, with no significant alterations in kidney function. These findings underscore the potential of benzofuroxan-based CA inhibitors for further preclinical evaluations as therapeutic agents targeting renal cell carcinoma.

The development of antibacterial drugs with new mechanisms of action is crucial in combating the rise of antibiotic-resistant infections. Bacterial carbonic anhydrases (CAs, EC 4.2.1.1) have been validated as promising antibacterial targets against pathogens such as Helicobacter pylori , Neisseria gonorrhoeae , and vancomycin-resistant enterococci. A multitarget strategy is proposed to design penicillin-based CA inhibitor hybrids for tackling resistance by targeting multiple bacterial pathways, thereby resensitizing drug-resistant strains to clinical antibiotics. The sulfonamide derivatives potently inhibited the CAs from N. gonorrhoeae and Escherichia coli with K I values in the range of 7.1-617.2 nM. Computational simulations with the main penicillin-binding protein (PBP) of N. gonorrhoeae indicated that these hybrid derivatives maintained the mechanism of action of the lead β-lactams. A subset of derivatives showed potent PBP-related antigonococcal effects against multidrug-resistant N. gonorrhoeae strains, with several compounds significantly outperforming both the lead β-lactam and CA inhibitor drugs (MIC values in the range 0.25 to 0.5 μg/mL).

In the pursuit of discovering new selective carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, a small collection of novel thiosemicarbazides (5a-5t) were designed and synthesized starting from 2-(hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide which was evaluated as a potent inhibitor of different CA isoforms in a previous study. The newly synthesized compounds were examined against four human carbonic anhydrases (hCA), namely transmembrane tumor-related hCA IX/XII and cytosolic widespread off-targets hCA I/II. In enzyme inhibition assays, all nineteen compounds display up to ∼340-fold selectivity for hCA IX/XII over off-target isoforms hCA I/II. Four compounds have enzyme inhibition values (K i ) lower than 10 nM against tumor-associated isoforms hCA IX/XII including two compounds in the subnanomolar range (5r and 5s; hCA XII; K i : 0.69 and 0.87 nM). The potential binding interactions of the most potent compounds against hCA IX and XII, compounds 5s and 5r, respectively, were investigated using ensemble docking and molecular dynamics studies. Cell viability assays using human colorectal adenocarcinoma cell line HT-29 and healthy skin fibroblasts CCD-86Sk show that compound 5e selectively inhibits HT-29 cancer cell proliferation (IC 50 : 53.32 ± 7.74 µM for HT-29; IC 50 : 74.64 ± 14.15 µM for CCD-986Sk). Finally, Western blot assays show that compounds 5e and 5r significantly reduce the expression of hCA XII in HT-29 cells. Moreover, 5e shows better cytotoxic activity in hypoxia compared to normoxic conditions. Altogether, the newly designed compounds show stronger inhibition of the tumor-associated hCA IX and XII isoforms and several tested compounds show selective cytotoxicity as well as downregulation of hCA XII expression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

2 H -Benzo[e][1,2,4]thiadiazin-3(4 H )-one 1,1-dioxide (BTD) based carbonic anhydrase (CA) inhibitors are here explored as new anti-mycobacterial agents. The chemical features of BTD derivatives meet the criteria for a potent inhibition of β-class CA isozymes. BTD derivatives show chemical features meeting the criteria for a potent inhibition of β-class CA isozymes. Specifically, three β-CAs (MtCA1, MtCA2, and MtCA3) were identified in Mycobacterium tuberculosis and their inhibition was shown to exert an antitubercular action. BTDs derivatives 2a-q effectively inhibited the mycobacterial CAs, especially MtCA2 and MtCA3, with K i values up to a low nanomolar range (MtCA3, K i = 15.1-2250 nM; MtCA2, K i = 38.1-4480 nM) and with a significant selectivity ratio over the off-target human CAs I and II. A computational study was conducted to elucidate the compound structure-activity relationship. Importantly, the most potent MtCA inhibitors demonstrated efficacy in inhibiting the growth of M. tuberculosis strains resistant to both rifampicin and isoniazid-standard reference drugs for Tuberculosis treatment.

In this study, The inhibitory actions of human carbonic anhydrase (CA, EC 4.2.1.1) (hCA) isoforms I, II, IX, and XII are being examined using recently synthesized substituted hydroxyl Schiff derivatives based on the quinazoline scaffold 4 - 22 . Quinazolines 2 , 3 , 4 , 5 , 7 , 10 , 15 , and 18 reduce the activity of hCA I isoform effectively to a Ki of 87.6-692.3 nM, which is nearly equivalent to or more potent than that of the standard drug AAZ (Ki, 250.0 nM). Similarly, quinazolines 2 , 3 , and 5 and quinazoline 14 effectively decrease the inhibitory activity of the hCA II isoform to a K I of 16.9-29.7 nM, comparable to that of AAZ (K i , 12.0 nM). The hCA IX isoform activity is substantially diminished by quinazolines 2 - 12 and 14 - 21 (K i , 8.9-88.3 nM against AAZ (K i , 25.0 nM). Further, the activity of the hCA XII isoform is markedly inhibited by the quinazolines 3 , 5 , 7 , 14 , and 16 (K i , 5.4-19.5 nM). Significant selectivity levels are demonstrated for inhibiting tumour-associated isoforms hCA IX over hCAI, for sulfonamide derivatives 6 - 15 (SI; 10.68-186.29), and 17 - 22 (SI; 12.52-57.65) compared to AAZ (SI; 10.0). Sulfonamide derivatives 4 - 22 (SI; 0.50-20.77) demonstrated a unique selectivity in the concurrent inhibition of hCA IX over hCA II compared to AAZ (SI; 0.48). Simultaneously, benzenesulfonamide derivative 14 revealed excellent selectivity for inhibiting hCA XII over hCA I (SI; 60.35), whereas compounds 5 - 8 , 12 - 14 , 16 , and 18 - 22 demonstrated remarkable selectivity for hCA XII inhibitory activity over hCA II (SI; 2.09-7.27) compared to AAZ (SI; 43.86 and 2.10, respectively). Molecular docking studies additionally support 8 to hCA IX and XII binding, thus indicating its potential as a lead compound for inhibitor development., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

A series of phthalimide-capped benzene sulphonamides ( 1 - 22 ) reported by our group for dengue protease inhibitory activity have been evaluated for their carbonic anhydrase (hCA, EC 4.2.1.1) inhibitory activity against hCA I, hCA II. Compounds 1 , 3 , 10 , and 15 showed hCA I inhibition, whereas 1 , 4 , and 10 showed hCA II inhibition at nanomolar concentrations. Among these compounds, 1 displayed potent inhibitory activity against the hCA I (Ki = 28.5 nM) and hCA II (Ki = 2.2 nM), being 10 and 6 times more potent than acetazolamide, a standard inhibitor (Ki = 250 nM and 12 nM), respectively. Furthermore, this compound displayed 14-fold selectivity towards the hCA II isoform compared to hCA I. Molecular docking and MD simulations were performed to understand the atomic level interactions responsible for the selectivity of compound 1 towards hCA II.

Human (h) carbonic anhydrase (CAs, EC 4.2.1.1) isoforms IX and XII were recently confirmed as anticancer targets against solid hypoxic tumours. The "three-tails approach" has been proposed as an extension of the forerunner "tail" and "dual-tail approach" to fully exploit the amino acid differences at the medium/outer active site rims among different hCAs and to obtain more isoform-selective inhibitors. Many three-tailed inhibitors (TTIs) showed higher selectivity against the tumour-associated isoforms hCA IX and XII with respect to the off-targets hCA I and II. X-ray crystallography studies were performed to investigate the binding mode of four TTIs in complex with a hCA IX mimic. The ability of the most potent and selective TTIs to reduce in vitro the viability of colon cancer (HT29), prostate adenocarcinoma (PC3), and breast cancer (ZR75-1) cell lines was evaluated in normoxic (21% O 2 ) and hypoxic (3% O 2 ) conditions demonstrating relevant anti-proliferative effects.

Human carbonic anhydrase (CA, EC 4.2.1.1) (hCA) isoforms I, II, IX, and XII were investigated for their inhibitory activity with a series of new Schiff's bases based on quinazoline scaffold 4 - 27 . The hCA I isoform was efficiently inhibited by Schiff's bases 4 - 6 , 10 - 19 , 22 - 27 and had an inhibition constant (Ki) value of 52.8-991.7 nM compared with AAZ (Ki, 250 nM). Amongst the quinazoline derivatives, the compounds 2 , 3 , 4 , 10 , 11 , 16 , 18 , 24 , 26 , and 27 were proven to be effective hCA II inhibitors, with Ki values of 10.8-52.6 nM, measuring up to AAZ (Ki, 12 nM). Compounds 2 - 27 revealed compelling hCA IX inhibitory interest with Ki values of 10.5-99.6 nM, rivaling AAZ (Ki, 25.0 nM). Quinazoline derivatives 3 , 10 , 11 , 13 , 15 - 19 , and 24 possessed potent hCA XII inhibitory activities with K I values of 5.4-25.5 nM vs. 5.7 nM of AAZ. Schiff's bases 7 , 8 , 9 , and 21 represented attractive antitumor hCA IX carbonic anhydrase inhibitors (CAIs) with K I rates (22.0, 34.8, 49.2, and 45.3 nM, respectively). Compounds 5 , 7 , 8 , 9 , 14 , 18 , 19 , and 21 showed hCA I inhibitors on hCA IX with a selectivity index of 22.46-107, while derivatives 12 , 14 , and 18 showed selective hCA I inhibitors on hCA XII with a selectivity profile of 45.04-58.58, in contrast to AAZ (SI, 10.0 and 43.86). Compounds 2 , 5 , 7 - 14 , 19 - 23 , and 25 showed a selectivity profile for hCA II inhibitors over hCA IX with a selectivity index of 2.02-19.67, whereas derivatives 5 , 7 , 8 , 13 , 14 , 15 , 17 , 20 , 21 , and 22 showed selective hCA II inhibitors on hCA XII with a selectivity profile of 4.84-26.60 balanced to AAZ (SI, 0.48 and 2.10).

Pyrazole-based carbohydrazone hybrids have been considered to be a remarkable class of compounds in pharmaceutical chemistry. Here, we reported bioactivities of 4-(3-(2-(arylidene)hydrazin-1-carbonyl)-5-phenyl-1H-pyrazol-1-yl)benzenesulfonamides (1-27) towards CA isoenzymes (hCA I, hCA II, hCA IX) and human oral squamous cell carcinoma cell line. Compounds 19 (Ki = 10.1 nM, hCA I/hCA IX = 749.6), 22 (Ki = 18.5 nM, hCA I/hCA IX = 429.2), 26 (Ki = 14.5 nM, hCA I/hCA IX = 596.9), 27 (Ki = 21.5 nM, hCA I/hCA IX = 413.1) were more potent and selective inhibitors of cancer-associated hCA IX isoenzyme. Compounds 22 and 26 were also found to be approximately three times more selective hCA IX inhibitors over off-target hCA II at low nanomolar. Compounds 19, 22, 23, 24, and 26 with IC 50 of 1.6-1.7 μM showed potent cytotoxicity against human oral squamous cell carcinoma cell line as compared with human gingival fibroblast, producing the tumor-specificity value over 100. This was due to its cytostatic growth inhibition accompanied by a slight but significant dose-dependent increase in cell shrinkage and subG1 cell accumulation and marginal activation of caspase 3 substrates. Bioassay results showed that carbohydrazone-based hybrids could be useful candidates to design novel anticancer compounds and selective carbonic anhydrase inhibitors., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Recently, different mechanisms for inhibition of carbonic anhydrases (CAs) have been reported, such as the classical zinc-binding (exerted by sulfonamides and carboxylic acids) as well as occluding the entrance of the CA active site (exerted by coumarins). In this manuscript, we studied the effect of combining the pharmacopheric parts responsible for these two mechanisms on CA inhibitory potency and selectivity through the design and synthesis of novel coumarins tethered with the zinc-binding sulfonamide (5a-f, 11a-b and 13a-b) or carboxylic acid (7a-f) groups. In addition, another set of coumarin derivatives (9a-b) with no zinc-binding group (ZBG) was designed to act as non-classical CA inhibitors. The synthesized coumarins were examined for their inhibitory activities towards four hCA isoforms I, II, IX and XII. Coumarin sulfonamides (5a-f, 11a-b and 13a-b) effectively inhibited both tumor-associated hCA IX (K I s: 8.9-133.5 nM) and hCA XII (K I s: 3.4-42.9 nM) isoforms, whereas coumarin carboxylic acids (7a-f) weakly affected hCA IX (K I s: 0.49-11.2 μM) and hCA XII (K I s: 0.51-10.1 μM) isoforms. The coumarin based inhibitors featuring zinc-binding sulfonamide or carboxylic acid group achieved low to moderate hCA IX/XII selectivity. Interestingly, the ZBG-free coumarin derivatives (9a-b) emerged not only as effective hCA IX (K I s = 93.3 and 63.8 nM, respectively) and hCA XII (K I s = 85.7 and 72.1 nM, respectively) inhibitors, but also as a highly hCA IX/XII selective inhibitors over the off-target hCA I/II isoforms (SIs > 1000). Coumarin 9a was further evaluated for its anti-proliferative effect on MCF-7 and PANC-1 cancer cell lines, as well as its effect on the cell cycle and apoptosis towards MCF-7 cell line., (Copyright © 2022 Elsevier Inc. All rights reserved.)

We report the production and biochemical characterization of an α-carbonic anhydrase (LrhCA) from gram-positive probiotic bacteria Lactobacillus rhamnosus GG. CAs form a family of metalloenzymes that catalyze hydration of CO 2 /interconversion between CO 2 and water to bicarbonate ions and protons. They are divided into eight independent gene families (α, β, γ, δ, ζ, η, θ, and ι). Interestingly, many pathogens have been identified with only β- and/or γ-CAs, which can be targeted with CA-specific inhibitors (CAIs) acting as anti-pathogen drugs. Since it is important to study the potential off-target effects of CAIs for both the human body and its commensal bacteria, we took L. rhamnosus GG as our study subject. To date, only a single α-CA has been identified in L. rhamnosus GG, which was successfully produced and biochemically characterized. LrhCA showed moderate catalytic activity with the following kinetic parameters: k cat of 9.86 × 10 5  s -1 and k cat /K M of 1.41 × 10 7  s -1  M -1 . Moderate inhibition was established with 11 of the 39 studied sulfonamides. The best inhibitors were 5-((4-aminophenyl)sulfonamido)-1,3,4-thiadiazole-2-sulfonamide, 4-(2-hydroxymethyl-4-nitrophenyl-sulfonamidoethyl)-benzenesulfonamide, and benzolamide with K i values of 319 nM, 378 nM, and 387 nM, respectively. The other compounds showed weaker inhibitory effects. The K i of acetazolamide, a classical CAI, was 733 nM. In vitro experiments with acetazolamide showed that it had no significant effect on cell growth in L. rhamnosus GG culture. Several sulfonamides, including acetazolamide, are in use as clinical drugs, making their inhibition data highly relevant to avoid any adverse off-target effects towards the human body and its probiotic organisms. KEY POINTS: • The α-carbonic anhydrase from Lactobacillus rhamnosus GG (LrhCA) is 24.3 kDa. • LrhCA has significant catalytic activity with a kcat of 9.9 × 105 s-1. • Acetazolamide resulted in a marginal inhibitory effect on cell growth., (© 2022. The Author(s).)

Carbonic anhydrases (CAs) continue to represent a relevant pharmaceutical target. The need of selective inhibitors and the involvement of these metalloenzymes in many multifaceted diseases boost the search for new ligands able to distinguish among the different CA isoforms, and for multifunctional systems simultaneously able to inhibit CAs and to interfere with other pathological events by interacting with additional targets. In this work, we successfully explored the possibility of preparing new CAs ligands by combining calixarenes with benzensulfonamide units. Inhibition tests towards three human CA isoforms evidenced, for some of the ligands, K i values in the nanomolar range and promising selectivity. X-ray and molecular modeling studies provided information on the mode of binding of these calixarene derivatives. Thanks to the encouraging results and the structural features typical of the calixarene scaffold, it is then possible to plan for the future the design of multifunctional inhibitors for this class of widely spread enzymes., (© 2021 Wiley-VCH GmbH.)

New C -glycosides and α,β-unsaturated ketones incorporating the 4-hydroxy-3-methoxyphenyl (vanillin) moiety as inhibitors of carbonic anhydrase (CA, EC 4.2.1.1) isoforms have been investigated. The inhibition profile of these compounds is presented against four human CA (hCA) isozymes, comprising hCAs I and II (cytosolic, ubiquitous enzymes) and hCAs IX and XII (tumour associated isozymes). Docking analysis of the inhibitors within the active sites of these enzymes has been performed and is discussed, showing that the observed selectivity could be explained in terms of an alternative pocket out of the CA active site where some of these compounds may bind. Several derivatives were identified as selective inhibitors of the tumour-associated hCA IX and XII. Their discovery might be a step in the strategy for finding an effective non-sulfonamide CA inhibitor useful in therapy/diagnosis of hypoxic tumours or other pathologies in which CA isoforms are involved.

A series of novel N-aryl-1-(4-sulfamoylphenyl)-5-(thiophen-2-yl)-1H-pyrazole-3-carboxamides was synthesized and examined as inhibitors of cytosolic (human) hCA I and hCA II, and cancer-related transmembrane hCA IX and hCA XII isoenzymes. AC2 was the most selective inhibitor towards cancer-related hCA IX while AC8 and AC9 selectively inhibited hCA XII over off-target isoenzymes. Anticancer effects of the compounds were evaluated towards human oral squamous cell carcinoma (OSCC) cell lines, human mesenchymal normal oral cells, breast (MCF7), prostate (PC3), non-small cell lung carcinoma cells (A549), and non-tumoral fetal lung fibroblast cells (MRC5). Compounds moderately showed cytotoxicity towards cancer cell lines. Among others, AC6 showed cell-specific cytotoxic activity and induced apoptosis in a dose-dependent manner without a significant change in the cell cycle distribution of MCF7. These results suggest that pyrazole-3-carboxamides need further molecular modification to increase their anticancer drug candidate potency., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nucleotide pyrophosphatase/phosphodiesterase3 (NPP3) catalyzes the hydrolysis of extracellular nucleotides. It is expressed by immune cells and some carcinomas, e.g. of kidney and colon. Together with ecto-5'-nucleotidase (CD73), NPP3 produces immunosuppressive, cancer-promoting adenosine, and has therefore been proposed as a target for cancer therapy. Here we report on the discovery of 4-[(4-methylphthalazin-1-yl)amino]benzenesulfonamide ( 1 ) as an inhibitor of human NPP3 identified by compound library screening. Subsequent structure-activity relationship (SAR) studies led to the potent competitive NPP3 inhibitor 2-methyl-5-{4-[(4-sulfamoylphenyl)amino]phthalazin-1-yl}benzenesulfonamide ( 23 , K i 53.7 nM versus the natural substrate ATP). Docking studies predicted its binding pose and interactions. While 23 displayed high selectivity versus other ecto-nucleotidases, it showed ancillary inhibition of two proposed anti-cancer targets, the carbonic anhydrases CA-II (K i 74.7 nM) and CA-IX (K i 20.3 nM). Thus, 23 may act as multi-target anti-cancer drug. SARs for NPP3 were steeper than for CAs leading to the identification of potent dual CA-II/CA-IX ( e.g. 34 ) as well as selective CA-IX inhibitors ( e.g. 31 )., Competing Interests: There is no conflict of interest to declare., (This journal is © The Royal Society of Chemistry.)

CDCA1 is a very peculiar member of the Carbonic Anhydrase (CA) family. It has been the first enzyme to show an efficient utilization of Cd(II) ions in Nature and a unique adaptation capability to live on the surface ocean. Indeed, in this environment, which is extremely depleted in essential metal ions, CDCA1 can utilize Zn(II) or Cd(II) as catalytic metal to support the metabolic needs of fast growing diatoms. In this paper we demonstrate a further catalytic versatility of this enzyme by using a combination of X-ray crystallography, molecular dynamics simulations and enzymatic experiments. First we identified the CO 2 binding site and the way in which this substrate travels from the environment to the enzyme active site. Then, starting from the observation of a structural similarity with the substrate entry route of CS 2 hydrolase from Acidanius A1-3 , we hypothesized and demonstrated that also CS 2 is a substrate for CDCA1. This finding is new and unexpected since until now only few CS 2 hydrolases have been characterized, and none of them is reported to have any CO 2 hydratase action. The physiological implications of this supplementary catalytic activity still remain to be unveiled. We suggest here that it could represent another ability of diatoms expressing CDCA1 to adapt to the external environment. Indeed, the ability of this enzyme to convert CS 2 could represent an alternative source of carbon acquisition for diatoms, in addition to CO 2 ., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors. Published by Elsevier B.V. on behalf of Research Network of Computational and Structural Biotechnology.)

In this research, rational design, synthesis, carbonic anhydrases (CAs) inhibitory effects, and cytotoxicities of the 4-(3-(2-arylidenehydrazine-1-carbonyl)-5-(thiophen-2-yl)-1H-pyrazole-1-yl)benzenesulfonamides 1-20 were reported. Compound 18 (Ki = 7.0 nM) was approximately 127 times more selective cancer-associated hCA IX inhibitor over hCA I, while compound 17 (Ki = 10.6 nM) was 47 times more selective inhibitor of hCA XI over hCA II compared to the acetazolamide. Compounds 11 (CC 50  = 5.2 μM) and 20 (CC 50  = 1.6 μM) showed comparative tumor-specificity (TS= > 38.5; >128.2) with doxorubicin (TS > 43.0) towards HSC-2 cancer cell line. Western blot analysis demonstrated that 11 induced slightly apoptosis whereas 20 did not induce detectable apoptosis. A preliminary analysis showed that some correlation of tumor-specificity of 1-20 with the chemical descriptors that reflect hydrophobic volume, dipole moment, lowest hydrophilic energy, and topological structure. Molecular docking simulations were applied to the synthesized ligands to elucidate the predicted binding mode and selectivity profiles towards hCA I, hCA II, and hCA IX., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Two sets of benzenesulfonamide-based effective human carbonic anhydrase (hCA) inhibitors have been developed using the tail approach. The inhibitory action of these novel molecules was examined against four isoforms: hCA I, hCA II, hCA VII, and hCA XII. Most of the molecules disclosed low to medium nanomolar range inhibition against all tested isoforms. Some of the synthesized derivatives selectively inhibited the epilepsy-involved isoforms hCA II and hCA VII, showing low nanomolar affinity. The anticonvulsant activity of selected sulfonamides was assessed using the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (sc-PTZ) in vivo models of epilepsy. These potent CA inhibitors effectively inhibited seizures in both epilepsy models. The most effective compounds showed long duration of action and abolished MES-induced seizures up to 6 h after drug administration. These sulfonamides were found to be orally active anticonvulsants, being nontoxic in neuronal cell lines and in animal models.

A library of iodoquinazolinones endowed with benzenesulfonamide moiety was designed and synthesized as human carbonic anhydrase (hCA) inhibitors. Compounds 4-17 showed generally poor activity against the cytosolic hCA I and hCA II isoforms. Contrarily they were more potent and showed a variable spectrum of selectivity against the tumor-specific isoforms hCA IX and hCA XII. The 4-iodophenyl derivative 12 and the 4-pyridinyl derivative 15 were the most active and selective in this series against hCA IX and hCA XII isoforms with K I of 18 and 9 nM, respectively. Compounds 12 and 15 were further screened for their cytotoxicity against MCF-7, HepG-2 and HCT-116 cancer cell lines besides WI38 and MCF-10A normal cell lines to determine their selectivity towards cancer cells. Compound 12 was selective towards HepG-2 and HCT-116 cell lines but less selective towards MCF-7. While compound 15 showed higher selectivity towards HepG-2 than HCT-116 and MCF-7 cell lines. The ability of compounds 12 and 15 to sensitize the cells against gamma irradiation's effect proved their potential radiosensitizing activity. Molecular docking analysis was carried out to discover the possible binding mode of the compounds within the active site of isoform hCA IX and XII. Compounds 12 and 15 revealed the probable fundamental interactions explaining the good activity and selectivity towards the tumor-specific isoforms., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ninhydrins show extensive application in organic chemistry and agriculture whereas they have been poorly investigated as bioactive molecules for medicinal chemistry purposes. A series of ninhydrin derivatives was here investigated for the inhibition of human carbonic anhydrases (CAs, EC 4.2.1.1), based on earlier evidence that gem diols are able to coordinate the metal ion from the CA active site. Ninhydrins demonstrated a micromolar inhibitory action against CA I and IX (K I s in the range 0.57-68.2 μM) and up to a nanomolar efficacy against CA II and VII (K I s in the range 0.025-78.2 μM), validated isoforms as targets in several CNS-related diseases. CA IV was instead weakly or poorly inhibited. A computational protocol based on docking, MM-GBSA and metadynamics calculations was used to elucidate the putative binding mode of this type of inhibitors to CA II and CA VII. The findings of this study testify that such pharmacologically underestimated ligands may represent interesting lead compounds for the development of CA inhibitors possessing an innovative mechanism of action, i.e., mono- or bis-coordination to the zinc ion through the diol moiety., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Inhibitory action of newly synthesised 4-(2-(2-substituted-thio-4-oxoquinazolin-3(4H)-yl)ethyl)benzenesulfonamides compounds 2-13 against human carbonic anhydrase (CA, EC 4.2.1.1) (hCA) isoforms I, II, IX, and XII, was evaluated. hCA I was efficiently inhibited by compounds 2-13 with inhibition constants (K I s) ranging from 57.8-740.2 nM. Compounds 2 , 3 , 4 , and 12 showed inhibitory action against hCA II with K I s between 6.4 and 14.2 nM. CA IX exhibited significant sensitivity to inhibition by derivatives 2-13 with K I values ranging from 7.1 to 93.6 nM. Compounds 2 , 3 , 4 , 8 , 9 , and 12 also exerted potent inhibitory action against hCA XII (K I s ranging from 3.1 to 20.2 nM). Molecular docking studies for the most potent compounds 2 and 3 were conducted to exhibit the binding mode towards hCA isoforms as a promising step for SAR analyses which showed similar interaction with co-crystallized ligands. As such, a subset of these mercaptoquinazolin-4(3H)-one compounds represented interesting leads for developing new efficient and selective carbonic anhydrase inhibitors (CAIs) for the management of a variety of diseases including glaucoma, epilepsy, arthritis and cancer.

Carbonic anhydrases (CAs, EC 4.2.1.1) are ubiquitous metalloenzymes involved in biosynthetic processes, transport, supply, and balance of CO 2 /HCO 3 - into the cell. In Bacteria, CAs avoid the depletion of the dissolved CO 2 /HCO 3 - from the cell, providing them to the central metabolism that is compromised without the CA activity. The involvement of CAs in the survival, pathogenicity, and virulence of several bacterial pathogenic species is recent. Here, we report the kinetic properties of the recombinant γ -CA (EcoCA γ ) encoded in the genome of Escherichia coli . EcoCA γ is an excellent catalyst for the physiological CO 2  s cat of 5.7 × 10 5  s -1 and k cat /K M s 6  M -1 s -1 . The EcoCA γ inhibition profile with a broad series of known CA inhibitors, the substituted benzene-sulphonamides, and clinically licenced drugs was explored. Benzolamide showed a K I lower than 100 nM. Our study reinforces the hypothesis that the synthesis of new drugs capable of interfering selectively with the bacterial CA activity, avoiding the inhibition of the human α -CAs, is achievable and may lead to novel antibacterials.

This paper presents the production and kinetic and inhibitory characterisation of β-carbonic anhydrase from the opportunistic bacterium Staphylococcus aureus (SauBCA). From the eight different carbonic anhydrase (CA) families known to date, humans have only the α-form, whereas many clinically relevant pathogens have β- and/or γ-form(s). Based on this discovery, β- and γ-CAs have been introduced as promising new anti-infective targets. The results of this study revealed that recombinant SauBCA possesses significant CO 2 hydration activity with a k cat of 1.46 × 10 5  s -1 and a k cat /K M of 2.56 × 10 7  s - 1 M -1 . Its enzymatic function was inhibited by various sulphonamides in the nanomolar - micromolar range, and the K i of acetazolamide was 628 nM. The best inhibitor was the clinically used sulfamide agent famotidine ( K i of 71 nM). The least efficient inhibitors were zonisamide and dorzolamide. Our work encourages further investigations of SauBCA in an attempt to discover novel drugs against staphylococcal infections.

We evaluated the hCA (CA, EC 4.2.1.1) inhibitory activity of novel 4-(2-(2-substituted-thio-4-oxoquinazolin-3(4H)-yl)ethyl)benzenesulfonamides (compounds 2-20 ) towards the isoforms I, II, IX, and XII. hCA Isoforms were effectively inhibited by most of new compounds comparable to those of AAZ. Compounds 2 and 4 showed interestingly efficient and selective antitumor (hCA IX and hCA XII) inhibitor activities (K I s; 40.7, 13.0, and 8.0, 10.8 nM, respectively). Compounds 4 and 5 showed selective hCA IX inhibitory activity over hCA I (SI; 95 and 24), hCA IX/hCA II (SI; 23 and 5.8) and selective hCA XII inhibitory activity over hCA I (SI; 70 and 44), hCA XII/hCA II, (SI; 17 and 10) respectively compared to AAZ. Compounds 12-17 , and 19-20 showed selective inhibitory activity towards hCA IX over hCA I and hCA II, with selectivity ranges of 27-195 and 3.2-19, respectively, while compounds 12 , 14-17 , and 19 exhibited selective inhibition towards hCA XII over hCA I and hCA II, with selectivity ratios of 48-158 and 5.4-31 respectively, compared to AAZ. Molecular docking analysis was carried out to investigate the selective interactions among the most active derivatives, 17 and 20 and hCAs isoenzymes. Compounds 17 and 20 , which are highly selective CA IX and XII inhibitors, exhibited excellent interaction within the putative binding site of both enzymes, comparable to the co-crystallized inhibitors.HighlightsQuinazoline-linked ethylbenzenesulfonamides inhibiting CA were synthesised.The new molecules potently inhibited the hCA isoforms I, II, IV, and IX.Compounds 4 and 5 were found to be selective hCA IX/hCA I and hCA IX/hCA II inhibitors.Compounds 4 and 5 were found to be selective hCA XII/hCA I and hCA XII/hCA II inhibitors.Compounds 12 - 17 , 19 , and 20 were found to be selective hCA IX/hCA I and hCA IX/hCA II inhibitors.Compounds 12 , 14 - 17 , 19 were found to be selective hCA XII/hCA I and hCA XII/hCA II inhibitors.Compounds 4 and 5 are selective hCA IX and XII inhibitors over hCA I (selectivity ratios of 95, 23, and 24, 5.8, respectively) and hCA II (selectivity ratios of 70, 17, and 44, 10 respectively). Compounds 12-17 , and 19-20 are selective hCA IX inhibitors over hCA I (selectivity ratios of 27-195) and hCA II (selectivity ratios of 3.2-19). Compounds 12 , 14-17 and 19 are also selective hCA XII inhibitors over hCA I (selectivity ratios of 48-158) and hCA II (selectivity ratios of 5.4-31).

In the present work, we report the design and synthesis of a set of iodinated quinazolinones carrying benzenesulfonamide moiety as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The target compounds showed promising inhibitory activity against the four examined human (h) CA isoforms; I, II, IX and XII. Compounds 4-18 displayed variable inhibition constants, ranging as follows: 7.6-782.8 nM for hCA I, 34.4-412.1 nM for hCA II, 29.1-2225.3 nM for hCA IX and 8.8-429.4 nM for hCA XII. Compound 9, the most potent against the tumor-specific CA IX/CA XII (K I  = 29.1 and 8.8 nM) gives the possibility to evaluate its cytotoxicity and selectivity in vitro against HepG-2, HCT-116 and MCF-7 cancer cell lines. Compound 9 showed significant cytotoxicity against the tumor cell lines (IC 50  = 1.78, 1.94 and 3.07 μM, respectively) and relatively lower toxicity against WI38 normal cell line. The radiosensitizing activity of compound 9 was evaluated and displayed an increase in the radiation-induced cell death in cancer cells after receiving a single dose of 8 Gy gamma radiation. Thus, radiation was able to enhance the antiproliferative activity of compound 9. Molecular docking of 9 into the active site of CA IX and XII revealed the key interactions that could explain its potent activity and selectivity towards these isoforms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

The "tail approach" has become a milestone in human carbonic anhydrase inhibitor (hCAI) design for various therapeutics, including antiglaucoma agents. Besides the classical hydrophobic/hydrophilic division of hCAs active site, several subpockets have been identified at the middle/outer active sites rim, which could be targeted to increase the CAI isoform selectivity. This postulate is explored here by three-tailed benzenesulfonamide CAIs ( TTI ) to fully exploit such amino acid differences among hCAs. In this proof-of-concept study, an extensive structure-activity relationship (SAR) study was carried out with 32 such benzenesulfonamides differing in tails combination that were assayed for hCAs I, II, IV, and XII inhibition. A structural study was undertaken by X-ray crystallography and in silico tools to assess the ligand/target interaction mode. The most active and selective inhibitors against isoforms implicated in glaucoma were assessed in a rabbit model of the disease achieving an intraocular pressure-lowering action comparable to the clinically used dorzolamide.

Carbonic anhydrases (CAs) are a well characterized family of metalloenzymes that are highly efficient in facilitating the interconversion between carbon dioxide and bicarbonate. Recently, CA activity has been associated with the LCIB (limiting CO 2 -inducible protein B) protein family, which has been an interesting target in aquatic photosynthetic microorganisms. To gain further insight into the catalytic mechanism of this new group of CAs, the X-ray structure of a highly active LCIB homolog (PtLCIB3) from the diatom Phaeodactylum tricornutum was determined. The CA activities of PtLCIB3, its paralog PtLCIB4 and a variety of their mutants were also measured. It was discovered that PtLCIB3 has a classic β-CA fold and its overall structure is highly similar to that of its homolog PtLCIB4. Subtle structural alterations between PtLCIB3 and PtLCIB4 indicate that an alternative proton-shuttle cavity could perhaps be one reason for their remarkable difference in CA activity. A potential alternative proton-shuttle route in the LCIB protein family is suggested based on these results.

Proteins are relevant antimicrobial drug targets, and among them, enzymes represent a significant group, since most of them catalyze reactions essential for supporting the central metabolism, or are necessary for the pathogen vitality. Genomic exploration of pathogenic and non-pathogenic microorganisms has revealed genes encoding for a superfamily of metalloenzymes, known as carbonic anhydrases (CAs, EC 4.2.1.1). CAs catalyze the physiologically crucial reversible reaction of the carbon dioxide hydration to bicarbonate and protons. Herein, we investigated the sulfonamide inhibition profile of the recombinant β -CA (CynT2) identified in the genome of the Gram-negative bacterium Escherichia coli . This biocatalyst is indispensable for the growth of the microbe at atmospheric pCO 2 . Surprisingly, this enzyme has not been investigated for its inhibition with any class of CA inhibitors. Here, we show that CynT2 was strongly inhibited by some substituted benzene-sulfonamides and the clinically used inhibitor sulpiride (K I s in the range of 82-97 nM). This study may be relevant for identifying novel CA inhibitors, as well as for another essential part of the drug discovery pipeline, such as the structure-activity relationship for this class of enzyme inhibitors.

Human carbonic anhydrase (CA; EC 4.2.1.1) isoforms II and VII are implicated in neuronal excitation, seizures, and neuropathic pain (NP). Their selective inhibition over off-target CAs is expected to produce an anti-NP action devoid of side effects due to promiscuous CA modulation. Here, a drug design strategy based on the observation of (dis)similarities between the target CA active sites was planned with benzenesulfonamide derivatives and, for the first time, a phosphorus-based linker. Potent and selective CA II/VII inhibitors were identified among the synthesized phenyl(thio)phosphon(amid)ates 3 - 22 . X-ray crystallography depicted the binding mode of phosphonic acid 3 to both CAs II and VII. The most promising derivatives, after evaluation of their stability in acidic media, were tested in a mouse model of oxaliplatin-induced neuropathy. The most potent compound racemic mixture was subjected to HPLC enantioseparation, and the identification of the eutomer, the ( S )-enantiomer, allowed to halve the dose totally relieving allodynia in mice.

Hypoxia, a common feature of solid tumours' microenvironment, is associated with an aggressive phenotype and is known to cause resistance to anticancer chemo- and radiotherapies. Tumour-associated carbonic anhydrases isoform IX (hCA IX), which is upregulated under hypoxia in many malignancies participating to the microenvironment acidosis, represents a valuable target for drug strategy against advanced solid tumours. To overcome cancer cell resistance and improve the efficacy of therapeutics, the use of bio-reducible prodrugs also known as Hypoxia-activated prodrugs (HAPs), represents an interesting strategy to be applied to target hCA IX isozyme through the design of selective carbonic anhydrase IX inhibitors (CAIs). Here, we report the design, synthesis and biological evaluations including CA inhibition assays, toxicity assays on zebrafish and viability assays on human cell lines (HT29 and HCT116) of new HAP-CAIs, harboring different bio-reducible moieties in nitroaromatic series and a benzenesulfonamide warhead to target hCA IX. The CA inhibition assays of this compound series showed a slight selectivity against hCA IX versus the cytosolic off-target hCA II and hCA I isozymes. Toxicity and viability assays have highlighted that the compound bearing the 2-nitroimidazole moiety possesses the lowest toxicity (LC 50 of 1400 µM) and shows interesting results on viability assays.

A new series of N,N -bis(alkanol)amine aryl diesters was synthesized and studied as dual P-glycoprotein (P-gp) and carbonic anhydrase XII inhibitors (CA XII). These hybrids should be able to synergistically overcome P-gp mediated multidrug resistance (MDR) in cancer cells. It was reported that the efflux activity of P-gp could be modulated by CA XII, as the pH reduction caused by CA XII inhibition produces a significant decrease in P-gp ATPase activity. The new compounds reported here feature both P-gp and CA XII binding moieties. These hybrids contain a N,N -bis(alkanol)amine diester scaffold found in P-glycoprotein ligands and a coumarin or benzene sulfonamide moiety to target CA XII. Many compounds displayed a dual activity against P-gp and CA XII being active in the Rhd 123 uptake test on K562/DOX cells and in the hCA XII inhibition test. On LoVo/DOX cells, that overexpress both P-gp and CA XII, some coumarin derivatives showed a high MDR reversal effect in Rhd 123 uptake and doxorubicin cytotoxicity enhancement tests. In particular, compounds 7 and 8 showed higher activity than verapamil and were more potent on LoVo/DOX than on K562/DOX cells overexpressing only P-gp. They can be considered as valuable candidates for selective P-gp/CA XII inhibition in MDR cancer cells.

The design of three dual-tailed sulfonamide series 11a-11g , 14a-14h , and 16a-16e as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors are presented. All compounds were evaluated for inhibitory action against pharmacologically relevant human CA isoforms I, II, IV, and VII. Compounds 11a-11g emerged as potent CA inhibitors against the four tested isoforms with a significant selectivity to CA II, which is implicated in glaucoma ( K i in the range 0.36-6.9 nM). X-ray crystallographic analysis of three compounds ( 11a , 11d , and 11g ) bound to CA II showed the validity of the adopted drug design strategy as specific moieties within the ligand structure interacted directly with the hydrophobic and hydrophilic halves of the CA II active site. Compounds 11b - 11d and 11g were evaluated for their intraocular pressure-lowering effects in a rabbit model of glaucoma. 11b and 11d showed significant efficacy when compared to the clinically used drug dorzolamide.