Discovery of carbon-11 labeled sulfonamide derivative: A PET tracer for imaging brain NLRP3 inflammasome

We report herein the discovery of a positron emission tomography (PET) tracer for the (NOD)-like receptor protein 3 (NLRP3). Our recent medicinal chemistry campaign on developing sulfonamide-based NLRP3 inhibitors led to an analog, 1, with a methoxy substituent amenable to labeling with carbon-11. PET/CT imaging studies indicated that [¹¹C]1 exhibited rapid blood-brain barrier (BBB) penetration and moderate brain uptake, as well as blockable uptake in the brain. [¹¹C]1, thus suggesting the potential to serve as a useful tool for imaging NLRP3 inflammasome in living brains.

Discovery of new phenyl sulfonyl-pyrimidine carboxylate derivatives as the potential multi-target drugs with effective anti-Alzheimer's action: Design, synthesis, crystal structure and in-vitro biological evaluation

Alzheimer's disease (AD) is multifactorial, progressive neurodegeneration with impaired behavioural and cognitive functions. The multitarget-directed ligand (MTDL) strategies are promising paradigm in drug development, potentially leading to new possible therapy options for complex AD. Herein, a series of novel MTDLs phenylsulfonyl-pyrimidine carboxylate (BS-1 to BS-24) derivatives were designed and synthesized for AD treatment. All the synthesized compounds were validated by ¹HNMR, ¹³CNMR, HRMS, and BS-19 were structurally validated by X-Ray single diffraction analysis. To evaluate the plausible binding affinity of designed compounds, molecular docking study was performed, and the result revealed their significant interaction with active sites of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The synthesized compounds displayed moderate to excellent in vitro enzyme inhibitory activity against AChE and BuChE at nanomolar (nM) concentration. Among 24 compounds (BS-1 to BS-24), the optimal compounds (BS-10 and BS-22) displayed potential inhibition against AChE; IC₅₀ = 47.33 ± 0.02 nM and 51.36 ± 0.04 nM and moderate inhibition against BuChE; IC₅₀ = 159.43 ± 0.72 nM and 153.3 ± 0.74 nM respectively. In the enzyme kinetics study, the compound BS-10 displayed non-competitive inhibition of AChE with Ki = 8 nM. Respective compounds BS-10 and BS-22 inhibited AChE-induced Aβ_1-42 aggregation in thioflavin T-assay at 10 μM and 20 μM, but BS-10 at 10 μM and 20 μM concentrations are found more potent than BS-22. In addition, the aggregation properties were determined by the dynamic light scattering (DLS) and was found that BS-10 and BS-22 could significantly inhibit self-induced as well as AChE-induced Aβ_1-42 aggregation. The effect of compounds (BS-10 and BS-22) on the viability of MC65 neuroblastoma cells and their capability to cross the blood-brain barrier (BBB) in PAMPA-BBB were further studied. Further, in silico approach was applied to analyze physicochemical and pharmacokinetics properties of the designed compounds via the SwissADME and PreADMET server. Hence, the novel phenylsulfonyl-pyrimidine carboxylate derivatives can act as promising leads in the development of AChE inhibitors and Aβ disaggregator for the treatment of AD.

Quarternary α-cyanobenzylsulfonamides: A new subclass of CAA fungicides with excellent anti-Oomycetes activity

A bioisosteric carboxamide - sulfonamide replacement explored during the optimization of an insecticide lead compound led to the surprising discovery of a formerly unknown subclass of the Carboxylic Acid Amide (CAA) fungicides, which is the very first CAA fungicide group without a carboxamide function. In this paper we present invention pathway, racemic and stereoselective synthesis routes, structure-activity relationship studies as well as resistance profile of this novel family of fungicides.

Discovery of cyclic sulfonamide derivatives as potent inhibitors of SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) continues to spread worldwide, with 25 million confirmed cases and 800 thousand deaths. Effective treatments to target SARS-CoV-2 are urgently needed. In the present study, we have identified a class of cyclic sulfonamide derivatives as novel SARS-CoV-2 inhibitors. Compound 13c of the synthesized compounds exhibited robust inhibitory activity (IC50 = 0.88 μM) against SARS-CoV-2 without cytotoxicity (CC50 > 25 μM), with a selectivity index (SI) of 30.7. In addition, compound 13c exhibited high oral bioavailability (77%) and metabolic stability with good safety profiles in hERG and cytotoxicity studies. The present study identified that cyclic sulfonamide derivatives are a promising new template for the development of anti-SARS-CoV-2 agents.

A New Inhibitor of ADAM17 Composed of a Zinc-Binding Dithiol Moiety and a Specificity Pocket-Binding Appendage

A disintegrin and metalloproteinase 17 (ADAM17) is a zinc-dependent enzyme that catalyzes the cleavage of the extracellular domains of various transmembrane proteins. ADAM17 is regarded as a promising drug target for the suppression of various diseases, including cancer metastasis. We synthesized a new ADAM17 inhibitor, SN-4, composed of a zinc-binding dithiol moiety and an appendage that specifically binds to a pocket of ADAM17. We show that SN-4 inhibits the ability of ADAM17 to cleave tumor necrosis factor α (TNF-α) in vitro. This activity was reduced by the addition of zinc, indicating the importance of the zinc chelating dithiol moiety. Inhibition of TNF-α cleavage by SN-4 in cells was also observed, and with an IC50 of 3.22 µM, SN-4 showed slightly higher activity than the well-studied ADAM17 inhibitor marimastat. Furthermore, SN-4 was shown to inhibit cleavage of CD44 by ADAM17, but not by ADAM10, and to suppress cell invasion. Molecular docking showed good fitting of the specificity pocket-binding group and one SH of SN-4 and hinted at possible means of structural optimization. This study provides clues for the development of potent and selective ADAM17 inhibitors.

Synthesis and evaluation of a UMI-77-based fluorescent probe for selective detecting Mcl-1 protein and imaging in living cancer cells

Development of efficient fluorescent probes for detecting the overexpressed Mcl-1 protein in living cells is imperative for the diagnosis and treatment of cancers. In this paper, a new UMI-77 based fluorescent probe (DNSH), was synthesized and characterized. DNSH bound to the hydrophobic pockets of Mcl-1 protein tightly and the binding affinity was 20-fold higher than that of previous developed Mcl-1 probe. DNSH exhibited specific fluorescence response to Mcl-1 protein rather than other proteins. In the presence of Mcl-1 protein, fluorescence emission of DNSH can be switched on. Furthermore, fluorescence colocalization experiment demonstrated that DNSH can be successfully used for imaging mitochondrial Mcl-1 protein in human prostate cancer cells without a washing process. These results showed that DNSH may find useful applications in biological research such as tracking Mcl-1 protein in living biological specimens.

Screening of benzenesulfonamide in combination with chemically diverse fragments against carbonic anhydrase by differential scanning fluorimetry

The differential scanning fluorimetry (DSF) screening of 5.692 fragments in combination with benzenesulfonamide (BSA) against bovine carbonic anhydrase (bCA) delivered >100 hits that either caused, on their own, a significant thermal shift (ΔTm, °C) in the protein melting temperature or significantly influenced the thermal shift observed for BSA alone. Three hits based on 1,2,3-triazole moiety represent the periphery of the recently reported potent inhibitors of hCA II, IX and XII which were efficacious in vivo. Such a re-discovery of suitable BSA periphery essentially validates the new fragment-based approach to the discovery of future CAIs. Structures of other validated fragment hits are reported.

Synthesis of new series of thiazol-(2(3H)-ylideneamino)benzenesulfonamide derivatives as carbonic anhydrase inhibitors

Human carbonic anhydrase I and II isoenzymes (hCA I and II) are important metabolic enzymes. In this study, a new series of thiazol-(2(3H)-ylideneamino)benzenesulfonamide derivatives were synthesized and also some inhibition parameters including IC50 (hydratese) and inhibition constant values (Ki , esterase) were determined. All studied compounds exhibited potent inhibition against these enzymes. They inhibited carbonic anhydrases (CAs) with the IC50 values of 113 to 395.8 nM (Ki  = 77.38-319.59 nM) for hCA I and 91.9 to 516 nM (Ki  = 62.79-425.89 nM) for hCA II. Among the compounds, 5c was found to be the most active one (Ki : 77.38 nM) for hCA I and 5g was found for hCA II with the value of 62.79 nM.

Novel benzofuran-based sulphonamides as selective carbonic anhydrases IX and XII inhibitors: synthesis and in vitro biological evaluation

Pursuing on our efforts toward searching for efficient hCA IX and hCA XII inhibitors, herein we report the design and synthesis of new sets of benzofuran-based sulphonamides (4a,b, 5a,b, 9a-c, and 10a-d), featuring the zinc anchoring benzenesulfonamide moiety linked to a benzofuran tail via a hydrazine or hydrazide linker. All the target benzofurans were examined for their inhibitory activities toward isoforms hCA I, II, IX, and XII. The target tumour-associated hCA IX and XII isoforms were efficiently inhibited with KIs spanning in ranges 10.0-97.5 and 10.1-71.8 nM, respectively. Interestingly, arylsulfonehydrazones 9 displayed the best selectivity toward hCA IX and XII over hCA I (SIs: 39.4-250.3 and 26.0-149.9, respectively), and over hCA II (SIs: 19.6-57.1 and 13.0-34.2, respectively). Furthermore, the target benzofurans were assessed for their anti-proliferative activity, according to US-NCI protocol, toward a panel of sixty cancer cell lines. Only benzofurans 5b and 10b possessed selective and moderate growth inhibitory activity toward certain cancer cell lines.

Synthesis of calix[4]azacrown substituted sulphonamides with antioxidant, acetylcholinesterase, butyrylcholinesterase, tyrosinase and carbonic anhydrase inhibitory action

A series of novel calix[4]azacrown substituted sulphonamide Schiff bases was synthesised by the reaction of calix[4]azacrown aldehydes with different substituted primary and secondary sulphonamides. The obtained novel compounds were investigated as inhibitors of six human (h) isoforms of carbonic anhydrases (CA, EC 4.2.1.1). Their antioxidant profile was assayed by various bioanalytical methods. The calix[4]azacrown substituted sulphonamide Schiff bases were also investigated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase enzymes, associated with several diseases such as Alzheimer, Parkinson, and pigmentation disorders. The new sulphonamides showed low to moderate inhibition against hCAs, AChE, BChE, and tyrosinase enzymes. However, some of them possessed relevant antioxidant activity, comparable with standard antioxidants used in the study.

Aspartic peptidase of Phialophora verrucosa as target of HIV peptidase inhibitors: blockage of its enzymatic activity and interference with fungal growth and macrophage interaction

Phialophora verrucosa causes several fungal human diseases, mainly chromoblastomycosis, which is extremely difficult to treat. Several studies have shown that human immunodeficiency virus peptidase inhibitors (HIV-PIs) are attractive candidates for antifungal therapies. This work focused on studying the action of HIV-PIs on peptidase activity secreted by P. verrucosa and their effects on fungal proliferation and macrophage interaction. We detected a peptidase activity from P. verrucosa able to cleave albumin, sensitive to pepstatin A and HIV-PIs, especially lopinavir, ritonavir and amprenavir, showing for the first time that this fungus secretes aspartic-type peptidase. Furthermore, lopinavir, ritonavir and nelfinavir reduced the fungal growth, causing remarkable ultrastructural alterations. Lopinavir and ritonavir also affected the conidia-macrophage adhesion and macrophage killing. Interestingly, P. verrucosa had its growth inhibited by ritonavir combined with either itraconazole or ketoconazole. Collectively, our results support the antifungal action of HIV-PIs and their relevance as a possible alternative therapy for fungal infections.

A potentiated cooperation of carbonic anhydrase IX and histone deacetylase inhibitors against cancer

The emergence of tumour recurrence and resistance limits the survival rate for most tumour-bearing patients. Only, combination therapies targeting pathways involved in the induction and in the maintenance of cancer growth and progression might potentially result in an enhanced therapeutic efficacy. Herein, we provided a prospective combination treatment that includes suberoylanilide hydroxamic acid (SAHA), a well-known inhibitor of histone deacetylases (HDACs), and SLC-0111, a novel inhibitor of carbonic anhydrase (CA) IX. We proved that HDAC inhibition with SAHA in combination with SLC-0111 affects cell viability and colony forming capability to greater extent than either treatment alone of breast, colorectal and melanoma cancer cells. At the molecular level, this therapeutic regimen resulted in a synergistically increase of histone H4 and p53 acetylation in all tested cell lines. Overall, our findings showed that SAHA and SLC-0111 can be regarded as very attractive combination providing a potential therapeutic strategy against different cancer models.

A novel indenone derivative selectively induces senescence in MDA-MB-231 (breast adenocarcinoma) cells

Triple-negative breast cancer is the most aggressive form of breast cancer with limited intervention options. Moreover, a number of belligerent therapeutic strategies adopted to treat such aggressive forms of cancer have demonstrated detrimental side effects. This necessitates exploration of targeted chemotherapeutics. We assessed the efficacy of a novel indenone derivative (nID) [(±)-N-(2-(-5-methoxy-1-oxo-3-(2-oxo-2-phenylethyl)-2,3-dihydro-1H-inden-2-yl)ethyl)-4-methylbenzenesulfonamide], synthesized by a novel internal nucleophile-assisted palladium-catalyzed hydration-olefin insertion cascade; against triple-negative breast cancer cells (MDA-MB-231). On 24 h treatment, the nID caused decline in the viability of MDA-MB-231 and MDA-MB-468 cells, but did not significantly (P < 0.05) affect WRL-68 (epithelial-like) cells. In fact, the nID demonstrated augmentation of p53 expression, and consequent p53-dependent senescence in both MDA-MB-231 and MDA-MB-468 cells, but not in WRL-68 cells. The breast cancer cells also exhibited reduced proliferation, downregulated p65/NF-κB and survivin, along with augmented p21Cip1/WAF1 expression, on treatment with the nID. This ensued cell cycle arrest at G1 stage, which might have driven the MDA-MB-231 cells to senescence. We observed a selectivity of the nID to target MDA-MB-231 cells, whereas WRL-68 cells did not show any considerable effect. The results underscored that the nID has potential to be developed into a cancer therapeutic.

Synthesis of GluN2A-selective NMDA receptor antagonists with an electron-rich aromatic B-ring

Glutamatergic N-Methyl-d-aspartate (NMDA) receptors are heterotetrameric ion channels that can be comprised of different subunits. GluN2A subunit-containing NMDA receptors are associated with diseases like anxiety, depression, and schizophrenia. However, the exact contribution of these NMDA receptor subtypes is still unclear. To understand better the role of the GluN2A-containing receptors, novel ligands were designed. In co-crystallization with the isolated binding site, TCN-201 (1) and analogs adopt a U-shape conformation with parallel orientation of rings A and B. In order to increase the π/π-interactions between these rings, ring B of TCN-201 was replaced bioisosterically by different electron-rich thiazole, oxazole, and isoxazole heterocycles. The inhibitory activity was measured by two-electrode voltage clamp experiments with Xenopus laevis oocytes expressing GluN2A-containing NMDA receptors. It was found that 21c, 31a, 37a, and 37b were able to inhibit the ion channel. The isoxazole derivative 37b was the most potent negative allosteric modulator displaying 40% of the TCN-201 activity at a concentration of 10 μM.

Synthesis and biological evaluation of ethacrynic acid derivatives bearing sulfonamides as potent anti-cancer agents

A series of ethacrynic acid (2-[2,3-dichloro-4-(2-methylidenebutanoyl)phenoxy]acetic acid) (EA, Edecrin) containing sulfonamides linked via three types of linkers namely 1,2-ethylenediamine, piperazine and 4-aminopiperidine was synthesized and subsequently evaluated in vitro against HL60 and HCT116 cancer cell lines. All the EA analogs, excluding 6a and 6c, showed anti-proliferative activity with IC_50s in the micromolar range (less than 4 uM). Three derivatives 6b, 7b and 7e were selected for their interesting dual activity on HL60 cell line in order to be further evaluated against a panel of cancer cell lines (HCT116, A549, MCF7, PC3, U87-MG and SKOV3) as well as on MRC5 as a normal cell line. These compounds displayed IC₅₀ values in nanomolar range against A549, MCF7, PC3 and HCT116 cell lines, deducing the discovery that piperazine or 4-aminopiperidine is the linker's best choice to develop EA analogs with highly potent anti-proliferative activities own up to 24 nM. Besides, in terms of selectivity, those linkers are more suitable offering safety ratios of up to 63.8.

Sulfonamide Derived Esters: Synthesis, Characterization, Density Functional Theory and Biological Evaluation through Experimental and Theoretical Approach

A series of new solid esters was synthesized by using greener chemistry strategy involving simple reaction of an alcohol with sulfonamide ligand. Characterization study of these methyl (1), ethyl (2) isopropyl (3) and n-butyl (4) ester of 4-((4-chlo-rophenylsulfonamido)methyl)cyclohexanecarboxylic acid was done by using FTIR, NMR mass spectrometry and X-ray crystallography. The compounds were optimized with Gaussian software according to basis set B3LYP/6-31G(d,p) and their different parameters related to structure were calculated. Furthermore, all compounds of the series were screened for their in vitro biological applications involving anti-bacterial (Chromohalobactor salixgens, Halomonas halofila, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Shiegella sonnei), anti-fungal (Aspergillus niger), anti-oxidant (DPPH scavenging activity) and enzyme inhibition (acetylcholine esterase and butyrylcholine esterase) study. Sulfonamide based esters were also docked against selected enzymes (AChE and BChE) using MOE software for their mode of binding. Results obtained from these biological evaluations showed that such compounds have potential against targeted activity.

Molybdic Acid-Functionalized Nano-Fe3O4@TiO2 as a Novel and Magnetically Separable Catalyst for the Synthesis of Coumarin-Containing Sulfonamide Derivatives

Supported molybdic acid on nano-Fe3O4@TiO2 (Fe3O4@TiO2@(CH2)3OMoO3H) has been successfully prepared, char-acterized and applied as a catalyst for the synthesis of sulfonamide containing coumarin moieties. The prepared Fe3O4nanoparticles by coprecipitation of Fe2+ and Fe3+ ions were treated with tetraethyl orthotitanate to obtain Fe3O4@TiO2. By anchoring 3-chloropropyltriethoxysilan on Fe3O4@TiO2 followed by reacting with molybdic acid, the desired catalyst was produced. The synthesized catalyst was characterized using XRD, SEM, EDS, FT-IR and VSM analysis. Fe3O4@TiO2@(CH2)3OMoO3H was used as a catalyst for the synthesis of sulfonamide containing coumarin moieties via a three-com-ponent reaction of aryl aldehydes, para-toluenesulfonamide and 4-hydroxycoumarin or 5,7-dihydroxy-4-methylcou-marin. The catalyst recovery test showed the catalyst is highly reusable without losing its activity.

Review of the Synthesis and Anticancer Properties of Pyrazolo[4,3-e][1,2,4]triazine Derivatives

This review focuses on the cytotoxic effect of new synthetic pyrazolo[4,3-e][1,2,4]triazine derivatives against different tumor cell lines. Some annulated pyrazolotriazines i.e., pyrazolo[4,3-e][1,2,4]triazolo[4,3-b][1,2,4]triazines and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine demonstrated significant broad cytotoxic activity in micromolar range concentration, which could have excellent potential to be new candidate therapeutic agents in cancer chemotherapy.

Visible Light Mediated Bidirectional Control over Carbonic Anhydrase Activity in Cells and in Vivo Using Azobenzenesulfonamides

Two azobenzenesulfonamide molecules with thermally stable cis configurations resulting from fluorination of positions ortho to the azo group are reported that can differentially regulate the activity of carbonic anhydrase in the trans and cis configurations. These fluorinated probes each use two distinct visible wavelengths (520 and 410 or 460 nm) for isomerization with high photoconversion efficiency. Correspondingly, the cis isomer of these systems is highly stable and persistent (as evidenced by structural studies in solid and solution state), permitting regulation of metalloenzyme activity without continuous irradiation. Herein, we use these probes to demonstrate the visible light mediated bidirectional control over the activity of zinc-dependent carbonic anhydrase in solution as an isolated protein, in intact live cells and in vivo in zebrafish during embryo development.

Synthesis and activity of isoleucine sulfonamide derivatives as novel botulinum neurotoxin serotype A light chain inhibitors

The botulinum neurotoxin (BoNT) is the most lethal protein known to man causing the deadly disease botulinum. The neurotoxin, composed of a heavy (HC) and light (LC) chain, work in concert to cause muscle paralysis. A therapeutic strategy to treat individuals infected with the neurotoxin is inhibiting the catalytic activity of the BoNT LC. We report the synthesis, inhibition study and computational docking analysis of novel small molecule BoNT/A LC inhibitors. A structure activity relationship study resulted in the discovery of d-isoleucine functionalized with a hydroxamic acid on the C-terminal and a biphenyl with chlorine at C- 2 connected by a sulfonamide linker at the N-terminus. This compound has a measured IC₅₀ of 0.587 µM for the BoNT/A LC. Computational docking analysis indicates the sulfonamide linker adopts a geometry that is advantageous for binding to the BoNT LC active site. In addition, Arg363 is predicted to be involved in key binding interactions with the scaffold in this study.

Piperidine scaffold as the novel P2-ligands in cyclopropyl-containing HIV-1 protease inhibitors: Structure-based design, synthesis, biological evaluation and docking study

A series of potent HIV-1 protease inhibitors, containing diverse piperidine analogues as the P2-ligands, 4-substituted phenylsulfonamides as the P2'-ligands and a hydrophobic cyclopropyl group as the P1'-ligand, were designed, synthesized and evaluated in this work. Among these twenty-four target compounds, many of them exhibited excellent activity against HIV-1 protease with half maximal inhibitory concentration (IC50) values below 20 nM. Particularly, compound 22a containing a (R)-piperidine-3-carboxamide as the P2-ligand and a 4-methoxylphenylsulfonamide as the P2'-ligand exhibited the most effective inhibitory activity with an IC50 value of 3.61 nM. More importantly, 22a exhibited activity with inhibition of 42% and 26% against wild-type and Darunavir (DRV)-resistant HIV-1 variants, respectively. Additionally, the molecular docking of 22a with HIV-1 protease provided insight into the ligand-binding properties, which was of great value for further study.

Design, synthesis, and pharmacological evaluation of novel and selective COX-2 inhibitors based on bumetanide scaffold

Herein, we describe the design and synthesis of new benzenesulfonamide derivatives as selective COX-2 inhibitors based on bumetanide scaffold. Benzenesulfonamides bearing both the pyrazole 6b and the triazoles 9a, 9c were good inhibitors of COX-2 with IC50 values of 0.32, 0.28 and 0.17 µM, respectively. These benzenesulfonamides 6b, 9a and 9c exhibited a higher selectivity index than the reference drug celecoxib. Molecular modeling study showed that incorporation of bumetanide led to a unique binding mode that is most likely the reason for the observed significant COX-2 selectivity. The anti-inflammatory activity of synthesized compounds revealed that triazoles 9a and 9c demonstrated higher efficacy than celecoxib upon using in vivo carrageenan-induced rat paw edema model. Most of the prepared compounds possess low ulcerogenic potential when administered orally. Therefore, these compounds have a great potential to be developed as safe therapeutics for inflammation, pain, and other diseases where COX-2 plays important role in their pathophysiology.

Synthesis, characterization, inhibition effects, and molecular docking studies as acetylcholinesterase, α-glycosidase, and carbonic anhydrase inhibitors of novel benzenesulfonamides incorporating 1,3,5-triazine structural motifs

Some metabolic enzyme inhibitors can be used in the treatment of many diseases. Therefore, synthesis and determination of alternative inhibitors are essential. In this study, the inhibition effect of newly synthesized compounds on carbonic anhydrase (cytosolic isoforms, hCA I and hCA II), α-glycosidase (α-GLY), and acetylcholinesterase (AChE) were investigated. The possible binding mechanism of the compounds with a high inhibitory effect on the active site of the enzyme was demonstrated by molecular docking method. We investigated the inhibition effects of novel synthesized compounds (MZ1-MZ11) on metabolic enzymes such as α-GLY, AChE, and hCA I and II. The compound MZ6 for AChE, MZ8 for CA I and CA II and MZ7 for α-GLY showed a very active inhibition profile (KIs 51.67 ± 4.76 for hCA I, 40.35 ± 5.74 nM for hCA II, 41.74 ± 8.08 nM for α-GLY and 335.76 ± 46.91 nM for AChE). The novel synthesized compounds (MZ1-MZ11) have a higher enzyme (α-GLY, AChE, hCA I, and II) inhibitory potential than ACR, TAC, and AZA, respectively. The compounds may have the potential to be used as alternative medicines after further research in the treatment of many diseases such as diabetes, Alzheimer's disease, heart failure, ulcer, and epilepsy.

Synthesis of Bi-heterocyclic Sulfonamides as Tyrosinase Inhibitors: Lineweaver-Burk Plot Evaluation and Computational Ascriptions

The designed bi-heterocyclic sulfonamides were synthesized through a two-step protocol and their structures were ascertained by spectral techniques including IR, 1H NMR and 13C NMR along with CHN analysis. The in vitro inhibitory effects of these sulfonamides were evaluated against tyrosinase and kinetics mechanism was analyzed by Lineweaver-Burk plots. The binding modes of these molecules were ascribed through molecular docking studies. These synthesized bi-heterocyclic molecules were identified as potent inhibitors relative to the standard (kojic acid) and compound 5 inhibited the tyrosinase non-competitively by forming an enzyme-inhibitor complex. The inhibition constant Ki (0.09 µM) for compound 5 was calculated from Dixon plots. Computational results also displayed that all compounds possessed good binding profile against tyrosinase and interacted with core residues of target protein.

Synthesis and Cytotoxic Activity of Chiral Sulfonamides Based on the 2-Azabicycloalkane Skeleton

A series of chiral sulfonamides containing the 2-azabicycloalkane scaffold were prepared from aza-Diels-Alder cycloadducts through their conversion to amines based on 2-azanorbornane or the bridged azepane skeleton, followed by the reaction with sulfonyl chlorides. The cytotoxic activity of the obtained bicyclic derivatives was evaluated using human hepatocellular carcinoma (HCC), medulloblastoma (MB), and glioblastoma (GBM) cell lines. Chosen compounds were shown to notably reduce cell viability as compared to nonmalignant cells.

Synthesis and evaluation of indium-111-labeled imidazothiadiazole sulfonamide derivative for single photon emission computed tomography imaging targeting carbonic anhydrase-IX

Carbonic anhydrase-IX (CA-IX) is a zinc enzyme overexpressed in the hypoxic regions of many types of solid tumors; therefore, in vivo imaging of CA-IX may contribute to cancer diagnosis. In this study, we newly designed and synthesized an ¹¹¹In-labeled CA-IX imaging agent based on an imidazothiadiazole sulfonamide (IS) scaffold conjugated with a chelating moiety, DO3A ([¹¹¹In]DO3A-IS1), and evaluated its utility for imaging of CA-IX high-expressing tumors. [¹¹¹In]DO3A-IS1 was successfully synthesized at a 76% radiochemical yield by reacting its precursor with ¹¹¹InCl₃ in acetate buffer. In in vitro assays, [¹¹¹In]DO3A-IS1 showed marked stability in murine plasma and greater binding to CA-IX high-expressing (HT-29) cells (118 ± 21% initial dose/mg protein) than CA-IX low-expressing (MDA-MB-231) cells (1.4 ± 0.3% initial dose/mg protein). Moreover, in an in vivo biodistribution assay, [¹¹¹In]DO3A-IS1 showed marked accumulation in the HT-29 tumor (8.71 ± 1.41% injected dose/g at 24 h postinjection). In addition, in a single photon emission computed tomography (SPECT) study, [¹¹¹In]DO3A-IS1 clearly and selectively visualized the HT-29 tumor as compared with the MDA-MB-231 tumor. These results indicate that [¹¹¹In]DO3A-IS1 may serve as a useful SPECT imaging agent with the novel scaffold targeting CA-IX.

Novel N-(Substituted) Thioacetamide Quinazolinone Benzenesulfonamides as Antimicrobial Agents

AIM

With the rapid emergence of antibiotic resistance, efforts are being made to obtain new selective antimicrobial agents. Hybridization between quinazolinone and benzenesulfonamide can provide new antimicrobial candidates. Also, the use of nanoparticles can help boost drug efficacy and lower side effects.

MATERIALS AND METHODS

Novel quinazolinone-benzenesulfonamide derivatives 5-18 were synthesized and screened for their antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, MRSA and yeast. The most potent compound 16 was conjugated with copper oxide nanoparticles 16-CuONPs by gamma irradiation (4.5 KGy). Characterization was performed using UV-Visible, TEM examination, XRD patterns and DLS. Moreover, compound 16 was used to synthesize two nanoformulations: 16-CNPs by loading 16 in chitosan nanoparticles and the nanocomposites 16-CuONPs-CNPs. Characterization of these nanoformulations was performed using TEM and zeta potential. Besides, the inhibitory profile against Staphylococcus aureus DNA gyrase was assayed. Cytotoxic evaluation of 16, 16-CNPs and 16-CuONPs-CNPs on normal VERO cell line was carried out to determine its relative safety. Molecular docking of 16 was performed inside the active site of S. aureus DNA gyrase.

RESULTS

Compound 16 was the most active in this series against all the tested strains and showed inhibition zones and MICs in the ranges of 25-36 mm and 0.31-5.0 µg/mL, respectively. The antimicrobial screening of the synthesized nanoformulations revealed that 16-CuONPs-CNPs displayed the most potent activity. The MBCs of 16 and the nanoformulations were measured and proved their bactericidal mode of action. The inhibitory profile against S. aureus DNA gyrase showed IC50 ranging from 10.57 to 27.32 µM. Cytotoxic evaluation of 16, 16-CNPs and 16-CuONPs-CNPs against normal VERO cell lines proved its relative safety (IC50= 927, 543 and 637 µg/mL, respectively). Molecular docking of 16 inside the active site of S. aureus DNA gyrase showed that it binds in the same manner as that of the co-crystallized ligand, ciprofloxacin.

CONCLUSION

Compound 16 could be considered as a new antimicrobial lead candidate with enhanced activity upon nanoformulation.

Tail approach synthesis of novel benzenesulfonamides incorporating 1,3,4-oxadiazole hybrids as potent inhibitor of carbonic anhydrase I, II, IX, and XII isoenzymes

Two new series of 1,3,4-oxadiazole benzenesulfonamide hybrids 3 and 4, having twenty novel compounds, have been designed and synthesized in order to assess their inhibition potential as CAIs against hCA I, II, IX, and XII. 'Tail approach' strategy has been used to design the aromatic sulfonamide scaffolds with carbonyl and amide linker. Excellent inhibitory activity against hCA I has been exhibited by compounds 3g and 4j, 3.5 magnitude of order better than reference drug AAZ (KI = 250 nM). Moreover, compound 4j (KI = 7.9 nM) effectively inhibited glaucoma-associated hCA II isoform as well as tumor-associated hCA IX isoform with KI = 16.3 nM. Further hCA XII was weakly inhibited by all the compounds with KI values ranging from 0.23 μM to 3.62 μM. Interestingly structure-activity relationship (SAR) study indicates that N-(3-nitrophenyl)-2-((5-(4-sulfamoylphenyl)-1,3,4-oxadiazol-2-yl)thio)acetamide (4j) is a potent compound to be investigated further for antiglaucoma and antitumor activity. The chemistry of the nature of different substitutions on the 1,3,4-oxadiazole bearing benzenesulfonamide substituted aromatic ring for potency and selectivity over one hCA isoform versus others is deliberated in the present study. In this context, the 1,3,4-oxadiazole motif can be a valuable tool worth developing for the procurement of novel and potent selective CAIs potentially useful for the management of a variety of diseases as chemotherapeutic agents.

Synthesis, Antitumor Evaluation, Molecular Modeling and Quantitative Structure-Activity Relationship (QSAR) of Novel 2-[(4-Amino-6-N-substituted-1,3,5-triazin-2-yl)methylthio]-4-chloro-5-methyl-N-(1H-benzo[d]imidazol-2(3H)-ylidene)Benzenesulfonamides

A series of novel 2-[(4-amino-6-R2-1,3,5-triazin-2-yl)methylthio]-4-chloro-5-methyl-N-(5-R1-1H-benzo[d]imidazol-2(3H)-ylidene)benzenesulfonamides 6-49 was synthesized by the reaction of 5-substituted ethyl 2-{5-R1-2-[N-(5-chloro-1H-benzo[d]imidazol-2(3H)-ylidene)sulfamoyl]-4-methylphenylthio}acetate with appropriate biguanide hydrochlorides. The most active compounds, 22 and 46, showed significant cytotoxic activity and selectivity against colon (HCT-116), breast (MCF-7) and cervical cancer (HeLa) cell lines (IC50: 7-11 µM; 15-24 µM and 11-18 µM), respectively. Further QSAR (Quantitative Structure-Activity Relationships) studies on the cytotoxic activity of investigated compounds toward HCT-116, MCF-7 and HeLa were performed by using different topological (2D) and conformational (3D) molecular descriptors based on the stepwise multiple linear regression technique (MLR). The QSAR studies allowed us to make three statistically significant and predictive models for them. Moreover, the molecular docking studies were carried out to evaluate the possible binding mode of the most active compounds, 22 and 46, within the active site of the MDM2 protein.

Benzylaminoethyureido-Tailed Benzenesulfonamides: Design, Synthesis, Kinetic and X-ray Investigations on Human Carbonic Anhydrases

A drug design strategy of carbonic anhydrase inhibitors (CAIs) belonging to sulfonamides incorporating ureidoethylaminobenzyl tails is presented. A variety of substitution patterns on the ring and the tails, located on para- or meta- positions with respect to the sulfonamide warheads were incorporated in the new compounds. Inhibition of human carbonic anhydrases (hCA) isoforms I, II, IX and XII, involving various pathologies, was assessed with the new compounds. Selective inhibitory profile towards hCA II was observed, the most active compounds being low nM inhibitors (KIs of 2.8-9.2 nM, respectively). Extensive X-ray crystallographic analysis of several sulfonamides in an adduct with hCA I allowed an in-depth understanding of their binding mode and to lay a detailed structure-activity relationship.

Synthesis, Anticancer Evaluation and Structure-Activity Analysis of Novel (E)- 5-(2-Arylvinyl)-1,3,4-oxadiazol-2-yl)benzenesulfonamides

To learn more about the structure-activity relationships of (E)-3-(5-styryl-1,3,4-oxadiazol-2-yl)benzenesulfonamide derivatives, which in our previous research displayed promising in vitro anticancer activity, we have synthesized a group of novel (E)-5-[(5-(2-arylvinyl)-1,3,4-oxadiazol-2-yl)]-4-chloro-2-R1-benzenesulfonamides 7-36 as well as (E)-4-[5-styryl1,3,4-oxadiazol-2-yl]benzenesulfonamides 47-50 and (E)-2-(2,4-dichlorophenyl)-5-(2-arylvinyl)-1,3,4-oxadiazols 51-55. All target derivatives were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. The obtained results were analyzed in order to explain the influence of a structure of the 2-aryl-vinyl substituent and benzenesulfonamide scaffold on the anti-tumor activity. Compound 31, bearing 5-nitrothiophene moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 0.5, 4, and 4.5 µM, respectively. Analysis of structure-activity relationship showed significant differences in activity depending on the substituent in position 3 of the benzenesulfonamide ring and indicated as the optimal meta position of the sulfonamide moiety relative to the oxadizole ring. In the next stage, chemometric analysis was performed basing on a set of computed molecular descriptors. Hierarchical cluster analysis was used to examine the internal structure of the obtained data and the quantitative structure-activity relationship (QSAR) analysis with multiple linear regression (MLR) method allowed for finding statistically significant models for predicting activity towards all three cancer cell lines.

Design, Synthesis, and Structure-Activity Relationships of 1,2,3-Triazole Benzenesulfonamides as New Selective Leucine-Zipper and Sterile-α Motif Kinase (ZAK) Inhibitors

ZAK is a new promising target for discovery of drugs with activity against antihypertrophic cardiomyopathy (HCM). A series of 1,2,3-triazole benzenesulfonamides were designed and synthesized as selective ZAK inhibitors. One of these compounds, 6p binds tightly to ZAK protein (Kd = 8.0 nM) and potently suppresses the kinase function of ZAK with single-digit nM (IC50 = 4.0 nM) and exhibits excellent selectivity in a KINOMEscan screening platform against a panel of 403 wild-type kinases. This compound dose dependently blocks p38/GATA-4 and JNK/c-Jun signaling and demonstrates promising in vivo anti-HCM efficacy upon oral administration in a spontaneous hypertensive rat (SHR) model. Compound 6p may serve as a lead compound for new anti-HCM drug discovery.

Synthesis and evaluation of novel S-benzyl- and S-alkylphthalimide- oxadiazole -benzenesulfonamide hybrids as inhibitors of dengue virus protease

Direct acting antiviral drugs (DAADs) are becoming therapeutics of choice for the treatment of viral infections. Successful development of anti HIV and HCV drugs by targeting the viral proteases has provided impetus for discovering newer DAADs. Dengue virus (DENV) protease, which is composed of two nonstructural proteins, NS2B and NS3pro, can be likewise exploited for discovering new anti-dengue therapeutics. In this study, we have linked together two pharmaceutically interesting motifs, namely 1,3,4-oxadiazole and benzenesulfonamide in two alternative series to develop novel S-benzylated and S-alkylphthalimidated hybrids. For the first series of hybrids, 4-aminobenzoic acid (1) was reacted with substituted benzenesulfonyl chlorides via its amino group, whereas the carboxylic acid side was elaborated to sulfonamido-1,3,4-oxadiazole-2-thiols (6a/b) in three steps. At this stage, the intermediates 6a/b were bifurcated to either S-alkylphthalimidated (8a-j) or S-benzylated (9a-c) hybrids by reacting with corresponding halides. For the alternative series of hybrids, the carboxylic acid group of probenecid (10) was similarly elaborated to sulfonamido-1,3,4-oxadiazole-2-thiols (13), and diverged to S-alkylphthalimidated (14a-f) and S-benzylated hybrids (15a-e). Bioactivity assays demonstrated that 8g and 8h are the most potent inhibitors among the synthesized analogs, exhibiting the IC50 values of 13.9 μM and 15.1 μM, respectively. Computational assessment predicted the binding of the inhibitors at an allosteric site developed in the open conformation of DENV2 NS2B/NS3pro. Taken together these findings point out that the synthesized hybrid inhibitors possess a great potential for further antiviral drug development.

Synthesis of some N-aroyl-2-oxindole benzenesulfonamide conjugates with carbonic anhydrase inhibitory activity

Implication of carbonic anhydrases (CAs) in many physiological functions made them attractive therapeutic targets. Herein, we report the synthesis of three series of benzenesulfonamide-based compounds (5a-e, 9a-e and 10a-e) as potential ligands to four of the human CA isoforms (hCA I, hCA II, hCA IX and hCA XII). All synthesized compounds were evaluated for their CA inhibitory activity. Most of the compounds preferentially inhibited the tumor-associated isoforms IX and XII. Series 9a-e and 10a-e showed the highest activity. Of particular interest was compound 10a which demonstrated the highest activity among all compounds with Ki of 68.3 and 21.5 nM against hCA IX and hCA XII, respectively, in addition to its highest selectivity index. To get deep insight on the interaction of compound 10a with CA, docking experiment was run to study the binding interaction with key amino acids and zinc ion in the catalytic site of the four isoforms studied.

New benzenesulfonamide scaffold-based cytotoxic agents: Design, synthesis, cell viability, apoptotic activity and radioactive tracing studies

A new series of thiazolidinone (5a-g), thiazinone (9a-g) and dithiazepinone (9a-g) heterocycles bearing a benzenesulfonamide scaffold was synthesized. Cytotoxicity of these derivatives was assessed against MCF-7, HepG2, HCT-116 and A549 cancer cell lines and activity was compared to the known cytotoxic agents doxorubicin and 5-FU where the most active compounds displayed better to nearly similar IC50 values to the reference compounds. For assessing selectivity, the most active derivatives against MCF-7, 5b, 5c and 5e, were also assessed against the normal breast cell line MCF-10 A where they demonstrated high selective cytotoxicity to cancerous cells over that to normal cells. Further, the effect of the most active compounds 5b-e on MCF-7 and HepG2 cell cycle phase distribution was assessed and the tested sulfonamide derivatives were found to induce accumulation of cells in the <2n phase. To further confirm apoptosis induction, caspase 8 and 9 levels in MCF-7 and HepG2 were evaluated before and after treatment with compounds 5b-e and were found to be significantly higher after exposure to the test agents. Since 5c was the most active, its effect on the cell cycle regulation was confirmed where it showed inhibition of the CDK2/cyclin E1. Finally, in vivo biodistribution study using radioiodinated-5c revealed a significant uptake and targeting ability into solid tumor in a xenograft mouse model.

Discovery of a Novel Benzenesulfonamide Analogue That Inhibits Proliferation and Metastasis Against Ovarian Cancer OVCAR-8 Cells

BACKGROUND

Ovarian cancer has been a salient public health concern in the world. It is necessary to develop novel antitumor drugs to treat ovarian cancer.

PURPOSE

This study investigated the synthesis, antiproliferation ability, antitumor mechanisms in vitro and in vivo of a novel benzenesulfonamide derivative.

METHODS

The novel benzenesulfonamide-1,2,3-triazole hybrid 7c was synthesized from 4-fluorobenzenesulfonyl chloride, prop-2-yn-1-amine and 1-(azidomethyl)-3-phenoxybenzene. The structure of this benzenesulfonamide-1,2,3-triazole hybrid 7c was confirmed by 13C NMR, and 1H NMR. Compound 7c was evaluated for its antitumor effects in vitro and in vivo against ovarian cancer OVCAR-8 cells.

RESULTS

We discovered that the benzenesulfonamide hybrid 7c potently inhibited cell proliferation against ovarian cancer. Especially, it inhibited cell proliferation with an IC50 value of 0.54μM against OVCAR-8 cells. It could inhibit migration and invasion against OVCAR-8 cells in a concentration-dependent and time-dependent manner. In addition, compound 7c affected the Wnt/β-catenin/GSK3β pathway against ovarian cancer OVCAR-8 cells. In vivo study suggested that compound 7c inhibited tumor growth remarkably without obvious toxicity.

CONCLUSION

In conclusion, benzenesulfonamide hybrid 7c could be a lead compound for further antitumor drug discovery to treat ovarian cancer.

A benzenesulfonamide derivative as a novel PET radioligand for CXCR4

CXCR4 is involved in various diseases such as inflammation, tumor growth, and cancer metastasis through the interaction with its natural endogenous ligand, chemokine CXCL12. In an effort to develop imaging probes for CXCR4, we developed a novel small molecule CXCR4-targeted PET agent (compound 5) by combining our established benzenesulfonamide scaffold with a labeling component by virtue of click chemistry. 5 shows nanomolar affinity (IC50 = 6.9 nM) against a known CXCR4 antagonist (TN14003) and inhibits more than 65% chemotaxis at 10 nM in vitro assays. Radiofluorinated compound 5 ([18F]5) demonstrates a competitive cellular uptake against CXCL12 in a dose-dependent manner. Further, microPET images of [18F]5 exhibits preferential accumulation of radioactivity in the lesions of λ-carrageenan-induced paw edema, human head and neck cancer orthotopic xenograft, and metastatic lung cancer of each mouse model.

Synthesis and evaluation of 4-(1,3,4-oxadiazol-2-yl)-benzenesulfonamides as potent carbonic anhydrase inhibitors

Human Carbonic anhydrase (hCA) I and II are crucial targets for anti-acute mountain sickness. Twenty-one 4-(1,3,4-oxadiazol-2-yl) benzenesulfonamides were synthesized and screened against these two isoforms. The results illustrated that 5c, 5g, 5h, 5k were more potent against both hCA I and II than clinical drug AAZ. In particular, the value of compound 5c with hCA I (18.08 nM) was over 84-fold more than of AAZ with hCA I. The data of docking simulations were also in accord with the tendency of inhibitive activities. Furthermore, compound 6h, the methanesulfonate of 5h, showed better anti-hypoxia activity than AAZ in vivo, making it interesting lead compound.

Halogenated and di-substituted benzenesulfonamides as selective inhibitors of carbonic anhydrase isoforms

By applying an approach of a "ring with two tails", a series of novel inhibitors possessing high-affinity and significant selectivity towards selected carbonic anhydrase (CA) isoforms has been designed. The "ring" consists of 2-chloro/bromo-benzenesulfonamide, where the sulfonamide group is as an anchor coordinating the Zn(II) in the active site of CAs, and halogen atom orients the ring affecting the affinity and selectivity. First "tail" is a substituent containing carbonyl, carboxyl, hydroxyl, ether groups or hydrophilic amide linkage. The second "tail" contains aryl- or alkyl-substituents attached through a sulfanyl or sulfonyl group. Both "tails" are connected to the benzene ring and play a crucial role in selectivity. Varying the substituents, we designed compounds selective for CA VII, CA IX, CA XII, or CA XIV. Since due to binding-linked protonation reactions the binding-ready fractions of the compound and protein are much lower than one, the "intrinsic" affinities were calculated that should be used to study correlations between crystal structures and the thermodynamics of binding for rational drug design. The "intrinsic" affinities together with the intrinsic enthalpies and entropies of binding together with co-crystal structures were used demonstrate structural factors determining major contributions for compound affinity and selectivity.

Synthesis, Bacterial biofilm inhibition and cytotoxicity of new N-Alkyl/aralkyl-N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamides

The current research was commenced by reaction of 1,4-benzodioxane-6-amine (1) with 4-nitrobenzenesulfonyl chloride (2) in the presence of aqueous base under dynamic pH control at 9 to yield N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamide (3) which was further reacted with a series of alkyl/aralkyl halides (4a-i) in polar aprotic solvent using catalytic amount of lithium hydride which acts as base to afford some new N-alkyl/aralkyl-N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-nitrobenzenesulfonamides (5a-i). The projected structures of all the synthesized derivatives were characterized by contemporary techniques i.e., IR, 1H-NMR and EIMS. The biofilm Inhibitory action of all synthesized molecules was carried out against Escherichia coli and Bacillus subtilis. It was inferred from their results that 5f and 5e exhibited suitable inhibitory action against the biofilms of these bacterial strains. Moreover, their cytotoxicity was also checked and it was concluded that these synthesized molecules displayed docile cytotoxicity.

Synthesis, biological and molecular dynamics investigations with a series of triazolopyrimidine/triazole-based benzenesulfonamides as novel carbonic anhydrase inhibitors

In the presented work, we report the design and synthesis of different new sets of triazolopyrimidine-based (9a-d) and triazole-based (11a-h, 13a-c, 15a,b, 17a,b and 21a-g) benzenesulfonamides. The newly synthesized sulfonamides were assessed for their inhibitory activities toward four human (h) metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) isoforms; hCA I, II, IX and XII. The four examined isoforms were inhibited by the prepared sulfonamides (9a-d, 11a-h, 13a-c, 15a,b, 17a,b and 21a-g) in variable degrees with KIs ranges: 94.4-4953.5 nM for hCA I, 6.9-837.6 nM for hCA II, 3.3-85.0 nM for hCA XI, and 4.4-105.0 nM for hCA XII. In particular, sulfonamides 11e, 21a and 21e emerged as single-digit nanomolar hCA IX and hCA XII inhibitors. Interestingly, triazolopyrimidine-based sulfonamide 9d and triazole-based sulfonamide 21e were found to be the most selective hCA IX inhibitors over hCA I (SI = 100.85 and 210.58, respectively) and hCA II (SI = 18.54 and 38.36, respectively). Thereafter, sulfonamides 9d and 21e were docked into the active site of CAs II, IX and XII, then poses showing the best scoring values and favorable binding interactions were subjected to a MM-GBSA based refinement and, limited to CA IX and XII, to a cycle of 100 ns molecular dynamics.

Substituted N-(Pyrazin-2-yl)benzenesulfonamides; Synthesis, Anti-Infective Evaluation, Cytotoxicity, and In Silico Studies

We prepared a series of substituted N-(pyrazin-2-yl)benzenesulfonamides as an attempt to investigate the effect of different linkers connecting pyrazine to benzene cores on antimicrobial activity when compared to our previous compounds of amide or retro-amide linker type. Only two compounds, 4-amino-N-(pyrazin-2-yl)benzenesulfonamide (MIC = 6.25 μg/mL, 25 μM) and 4-amino-N-(6-chloropyrazin-2-yl)benzenesulfonamide (MIC = 6.25 μg/mL, 22 μM) exerted good antitubercular activity against M. tuberculosis H37Rv. However, they were excluded from the comparison as they-unlike the other compounds-possessed the pharmacophore for the inhibition of folate pathway, which was proven by docking studies. We performed target fishing, where we identified matrix metalloproteinase-8 as a promising target for our title compounds that is worth future exploration.

3-Hydrazinoisatin-based benzenesulfonamides as novel carbonic anhydrase inhibitors endowed with anticancer activity: Synthesis, in vitro biological evaluation and in silico insights

Herein we describe the design and synthesis of two series of sulfonamides featuring N-unsubstituted (4a-c) or N-substituted (7a-o) isatin moieties (as tails) connected to benzenesulfonamide moiety via a hydrazine linker. All the prepared sulfonamides (4a-c and 7a-o) showed potent inhibitory activities toward transmembrane tumor-associated human (h) carbonic anhydrase (hCA, EC 4.2.1.1) isoforms, IX and XII with KI range (8.3-65.4 nM) and (11.9-72.9 nM), respectively. Furthermore, six sulfonamides (7e, 7i, 7j, 7m, 7n and 7o) were assessed for their anti-proliferative activity, according to US-NCI protocol, toward a panel of sixty cancer cell lines. Compounds 7j and 7n were the most promising counterparts in this assay displaying broad spectrum anti-proliferative activity toward diverse cell lines. Also, sulfonamide 7n significantly inhibited clonogenicity of HCT-116 cells in a concentration dependent manner in the colony forming assay. Moreover, molecular modeling studies were performed to gain insights for the plausible binding interactions and affinities for the target isatin-based sulfonamides (4a-c and 7a-o) within hCA isoforms II and IX active sites.

A Scaffold-Diversity Synthesis of Biologically Intriguing Cyclic Sulfonamides

A "branching-folding" synthetic strategy that affords a range of diverse cyclic benzo-sulfonamide scaffolds is presented. Whereas different annulation reactions on common ketimine substrates build the branching phase of the scaffold synthesis, a common hydrogenative ring-expansion method, facilitated by an increase of the ring-strain during the branching phase, led to sulfonamides bearing medium-sized rings in a folding pathway. Cell painting assay was successfully employed to identify tubulin targeting sulfonamides as novel mitotic inhibitors.

Novel sulphonamide benzoquinazolinones as dual EGFR/HER2 inhibitors, apoptosis inducers and radiosensitizers

A series of sulphonamide benzoquinazolinones 5-18 was synthesized and evaluated for cytotoxic activity against MDA-MB-231 cell line. The compounds showed IC₅₀ ranging from 0.26 to 161.49 µM. The promising compounds were evaluated for their inhibitory profile against epidermal growth factor (EGFR) and HER2 enzymes. Compound 10 showed more potent activity on both EGFR and HER2 than erlotinib (IC₅₀ 3.90 and 5.40 µM versus 6.21 and 9.42 µM). The pro-apoptotic activity of 10 was evaluated against caspase-3, Bax, B-cell lymphoma protein 2 (Bcl-2) expression levels, and cell cycle analysis. Compound 10 increased the level of caspase-3 by 10 folds, Bax level by 9 folds, decreased the level of the Bcl-2 by 0.14 and arrested the cell cycle in the G2/M phase. The radio-sensitizing activity of 10 was measured using a single dose of 8 Gy gamma radiation (IC₅₀ decreased from 0.31 to 0.22 µM). Molecular docking was performed on EGFR and HER2 receptors.

Continued exploration and tail approach synthesis of benzenesulfonamides containing triazole and dual triazole moieties as carbonic anhydrase I, II, IV and IX inhibitors

A library of twenty two novel 1,2,3-triazole benzenesulfonamides incorporating thiosemicarbazide, 5(4H)-thione-1,2,4-triazole and variously substituted phenacyl appended 1,2,4-triazole as tail were designed, synthesized and assessed for their efficacy as inhibitors against carbonic anhydrase human (h) isoforms hCA I, II, IV and IX. The physiologically important and off-target cytosolic isoform hCA I was weakly inhibited by most of the newly synthesized sulfonamides while the glaucoma associated isoform hCA II was moderately inhibited with KIs spanning in low nanomolar range (KI = 8.0 nM-0.903 μM). The membrane bound isoform hCA IV, which is known to be involved in glaucoma and retinitis pigmentosa among others, was strongly inhibited by all newly synthesized sulfonamides out of which nine compounds inhibited isoform hCA IV even more effectively as compared to standard drug acetazolamide (AAZ). The membrane bound isoform hCA IX, associated with growth of tumor cells, was moderately inhibited with KIs ranging between 51 nM-3.198 μM. The effect of appending variously substituted tails on heterocyclic moieties over inhibition potential of synthesized sulfonamides is also disclosed which can be of further interest in pharmacological studies for exploring synthesis of isoform selective inhibitors.

Synthesis and biological evaluation of novel 3-(quinolin-4-ylamino)benzenesulfonamidesAQ3 as carbonic anhydrase isoforms I and II inhibitors

Carbonic anhydrases (CAs, EC 4.2.1.1) are crucial metalloenzymes that are involved in diverse bioprocesses. We report the synthesis and biological evaluation of novel series of benzenesulfonamides incorporating un/substituted ethyl quinoline-3-carboxylate moieties. The newly synthesised compounds were in vitro evaluated as inhibitors of the cytosolic human (h) isoforms hCA I and II. Both isoforms hCA I and II were inhibited by the quinolines reported here in variable degrees: hCA I was inhibited with KIs in the range of 0.966-9.091 μM, whereas hCA II in the range of 0.083-3.594 μM. The primary 7-chloro-6-flouro substituted sulphfonamide derivative 6e (KI = 0.083 μM) proved to be the most active quinoline in inhibiting hCA II, whereas, its secondary sulfonamide analog failed to inhibit the hCA II up to 10 μM, confirming the crucial role of the primary sulphfonamide group, as a zinc-binding group for CA inhibitory activity.

Novel halogenated sulfonamide biguanides with anti-coagulation properties

Apart from its hypoglycaemic properties, metformin also offers beneficial effects for the cardiovascular system resulting in significant reduction of diabetes-related death, and all-cause mortality. The aim of this study was to synthesize nine new benzenesulfonamide derivatives of metformin with a halogen substituent, and estimate their influence on selected parameters of plasma and vascular hemostasis. The study describes the synthesis of nine benzenesulfonamide biguanides with o-, m-, and p- chloro-, bromo-, and fluoro substituents. All orto- derivatives (chloro- (1), bromo- (4), and fluoro- (7)) significantly prolong prothrombin time (PT) and partially activated thromboplastin time (APTT). In addition compounds 4 and 7 slow the process of fibrin polymerization, and contribute to increased TT. Multiparametric CL-test revealed that compounds 1, 4, 7 and p-fluorobenzenesulfonamide (9) significantly prolong the onset of clot formation, decrease initial clot formation velocity, and maximum clotting. Analysis of human endothelial cell (HUVECs) and human aortal smooth muscle cell (AoSMCs) viability over the entire tested concentration range (0.001-3.0 μmol/mL) indicated that the examined compounds can undergo further tests up to 1.5 µmol/mL concentration without decreasing cellular viability. Furthermore, none of the synthesized compounds exert an unfavourable effect on erythrocyte integrity, and thus do not interact strongly with the lipid-protein bilayer. In summary, chemical modification of the metformin backbone into benzenesulfonamides containing halogen substituents at the o- position leads to the formation of potential agents with stronger anti-coagulant properties than the parent drug, metformin. Therefore, o-halogenated benzenesulfonamides can be regarded as an initial promising step in the development of novel biguanide-based compounds with anti-coagulant properties.

New carboxamides bearing benzenesulphonamides: Synthesis, molecular docking and pharmacological properties

Ten new derivatives of benzenesulphonamide bearing carboxamide functionality were synthesized and investigated for their in vitro antimicrobial, antioxidant and in vivo anti-inflammatory activities. Compound 9d inhibited carrageenan induced rat-paw oedema at 93.81, 88.79 and 86.09% at 1 h, 2 h and 3 h administration respectively. In the antimicrobial activity, compound 9a (6.54, 6.69 and 6.64 mg/mL) was most potent against S. aureus, B. subtilis and C. albicans respectively, compound 9e (6.45 and 6.46 mg/mL) was most active against P. aeruginosa and A. niger respectively while compound 9i (6.24 mg/mL) was most active against E. coli. Only compound 9a (IC50 0.3052 mg/mL) had comparable activity with Vitamin C (IC50 0.2090 mg/mL) in the antioxidant assay.