Sulfa drug analogs: new classes of N-sulfonyl aminated azines and their biological and preclinical importance in medicinal chemistry (2000–2018)

Construction of Biaryl Sulfonamides via Pd(II)-Catalyzed Cross-Coupling of C(sp2)-H Bonds with Iodobenzenesulfonamides

This study describes the utility of Pd(II)-catalyzed C-H arylation of benzamides for constructing biaryl sulfonamides. Sulfonamides are known for their promising applications in pharmaceuticals and agrochemicals. A literature review revealed that biaryl sulfonamides were generally constructed via the traditional cross-coupling reactions. We report a progressive method for obtaining biaryl sulfonamides via the Pd(II)-catalyzed bidentate directing group (8-aminoquinoline or picolinamide)-assisted cross-coupling of sp2 C-H bonds of aromatic carboxamides with iodobenzenesulfonamides. After the C-H arylation reactions, we attempted the removal of the 8-aminoquinoline from the synthesized biaryl scaffolds possessing the carboxamide and sulfonamide moieties using triflic acid. In some cases, we observed the occurrence of decarboxylation and Friedel-Crafts acylation, affording interesting aromatic scaffolds possessing the sulfonamide moiety. The current work contributes toward developing alternative ways for assembling various biaryl sulfonamides.

Exploring the Versatility of Azine Derivatives: A Comprehensive Review on Synthesis and Biological Applications

Organic compounds containing azines, di-imines, or bis-Schiff-bases have two azomethine (-CH=N-) functional groups associated with a bridging component. These constituents have attracted attention from a diversity of disciplines, comprising coordination, medicinal, agriculture chemistry, and organic synthesis, because of their comprehensive chemical reactivity and nature. This study determines common synthetic approaches and various biological and pharmacological activities of several substituted bis-Schiff byproducts. The usefulness of bis-Schiff bases in synthetic chemistry and their potential as inhibitors of a number of enzymes have attracted research attention. We have examined different biological activities and common synthetic methods used to make bis- Schiff bases that have been published in the literature. A systematic search of the literature has been performed, and studies fitting the prearranged inclusion standards have been inspected. This review can open up new potentials for upcoming research in this area and advance our information on bis- Schiff bases.

Regioselective Ring Opening of Aziridines by Oximes via C-C Bond Cleavage: Access to a Library of Oxime-Ethers

A series of sulfonamido-substituted oxime-ethers have been synthesized by the reaction of donor-acceptor aziridines with aldo- and keto-oximes through C-C bond cleavage. Nucleophilic attack by an oxime hydroxyl group on the in situ-generated azomethine ylide rather than the routine cycloaddition reaction draws the novelty of the developed methodology. Selective protection of the oxime hydroxyl group is observed in the presence of phenolic -OH, which made the protocol enriched. In terms of a synthetic point of view, the uniqueness had been drawn further as it occurred at room temperature and within 30 min. Participation of a wide range of aziridines with a series of aldo- and keto-oximes made the developed methodology generalized by creating a novel library of substituted oxime-ethers.

Palladium catalyzed C(sp3)-H alkylation of 8-methylquinolines with aziridines: access to functionalized γ-quinolinylpropylamines

Palladium-catalyzed directed site-selective C(sp3)-H alkylation of 8-methylquinolines has been accomplished using aziridine as the alkylating source via a sequential C-H and C-N bond activation process. The site selectivity, functional group tolerance and possible late-stage modifications are important practical features of this reaction.

Discovery of new anti-diabetic potential agents based on paracetamol incorporating sulfa-drugs: Design, synthesis, α-amylase, and α-glucosidase inhibitors with molecular docking simulation

Uncontrolled diabetes can lead to hyperglycemia, which causes neuropathy, heart attacks, retinopathy, and nervous system damage over time, therefore, controlling hyperglycemia using potential drug target inhibitors is a promising strategy. This work focused on synthesizing new derivatives via the diazo group, using a hybridization strategy involving two approved drugs, paracetamol and several sulfonamides. The newly designed diazo-paracetamols 5-12 were fully characterized and then screened for in vitro α-amylase and α-glucosidase activities and exhibited inhibitory percentages (IP) = 92.5-96.5 % and 91.0-95.7 % compared to Acarbose IP = 96.5 and 95.8 %, respectively at 100 μg/mL. The IC50 values of the synthesized derivatives were evaluated against α-amylase and α-glucosidase enzymes, and the results demonstrated moderate to potent activity. Among the tested diazo-paracetamols, compound 11 was found to have the highest potency activity against α-amylase with IC50 value of 0.98 ± 0.015 μM compared to Acarbose IC50 = 0.43 ± 0.009 μM, followed by compound 10 (IC50 = 1.55 ± 0.022 μM) and compound 9 (IC50 = 1.59 ± 0.023 μM). On the other hand, for α-glucosidase, compound 10 with pyrimidine moiety demonstrated the highest inhibitory activity with IC50 = 1.39 ± 0.021 μM relative to Acarbose IC50 = 1.24 ± 0.029 μM and the order of the most active derivatives was 10 > 9 (IC50 = 2.95 ± 0.046 μM) > 11 (IC50 = 5.13 ± 0.082 μM). SAR analysis confirmed that the presence of 4,5-dimethyl-isoxazole or pyrimidine nucleus attached to the sulfonyl group is important for activity. Finally, the docking simulation was achieved to determine the mode of binding interactions for the most active derivatives in the enzyme's active site.

Syntheses and biological activities of calix[4]resorcinarene derivatives modified by sulfonic acid and sulfonamides

Functionalization of C-propyl-resorcinolcalix[4]arene (1a) and C-iso-butyl-resorcinolcalix[4]arene (1b) with sodium sulfite and formaldehyde solution gave two corresponding sulfonatomethylated calix[4]resorcinarenes 2a/b. Further modification of 2a/b with different primary amines afforded three calix[4]resorcinarene sulfonamides 3a/b and 4c. Antibacterial and antitumor tests were performed on the starting calix[4]resorcinarenes and their sulfonic acid and sulfonamide derivatives. The results showed that in terms of antimicrobial activity calix[4]resorcinarenes and their derivatives showed bacteriostatic activity against both Escherichia coli and Staphylococcus aureus. Of which compound 1b was the most effective against Escherichia coli with a MIC value of 6.25 mg mL; compound 2b was the most effective against Staphylococcus aureus with a MIC value of 3.12 mg mL-1. In terms of antitumor activity, calix[4]resorcinarenes and their derivatives showed inhibitory effects on the three tumor cells selected for the experiment. Among them, the survival rate of A549 was 76.03% in the presence of 40 μM 1b, and the survival rates of HepG2 and MDA-MB-321 were 28.66% and 65.39% in the presence of 40 μM 2b, respectively.

Crystal structure of 2-[(5-amino-1-tosyl-1H-pyrazol-3-yl)-oxy]-1-(4-meth-oxy-phen-yl)ethan-1-one 1,4-dioxane monosolvate

In the structure of the title compound, C19H19N3O5S·C4H8O2, the two independent dioxane mol-ecules each display inversion symmetry. The pyrazole ring is approximately parallel to the aromatic ring of the oxy-ethanone group and approximately perpendicular to the tolyl ring of the sulfonyl substituent. An extensive system of classical and 'weak' hydrogen bonds connects the residues to form a layer structure parallel to (201), within which dimeric subunits are conspicuous; neighbouring layers are connected by classical hydrogen bonds to dioxanes and by 'weak' hydrogen bonds from Htol-yl donors.

Synthesis and Insecticidal Activity Study of Azidopyridryl Containing Dichlorolpropene Ether Derivatives

Pyridalyl, as a novel insecticide with an unknown mode of action, has shown excellent control efficacy against lepidopterous larvae and thrips. Previous modifications of this compound have mostly focused on the pyridine moiety, with limited information available about modifications to other parts of pyridalyl. In this paper, we report the synthesis and insecticidal activity of a series of azidopyridryl-containing dichlorolpropene ether derivatives, based on modifications to the middle alkyl chain of pyridalyl. Screening results for insecticidal activity indicate that our synthesized compounds show moderate to high activities at the tested concentrations against P. xylostella. Particularly, compound III-10 exhibits a LC50 value of 0.831 mg L-1, compared to the LC50 value of pyridalyl at 2.021 mg L-1. Furthermore, compound III-10 also displays a relatively broad insecticidal spectrum against Lepidoptera pests M. separata, C. suppressalis, O. nubilalis, and C. medinalis. Finally, in field trials, III-10 demonstrates better control efficiency against Chilo suppressalis compared to pyridalyl. Overall, our findings suggest that the modification of the middle alkyl chain of pyridalyl may be a promising approach for developing insecticides with improved efficacy.

Novel inhibitors that target bacterial virulence identified via HTS against intra-macrophage survival of Shigella flexneri

Shigella flexneri is a facultative intracellular pathogen that causes shigellosis, a human diarrheal disease characterized by the destruction of the colonic epithelium. Novel antimicrobial compounds to treat infections are urgently needed due to the proliferation of bacterial antibiotic resistance and lack of new effective antimicrobials in the market. Our approach to find compounds that block the Shigella virulence pathway has three potential advantages: (i) resistance development should be minimized due to the lack of growth selection pressure, (ii) no resistance due to environmental antibiotic exposure should be developed since the virulence pathways are not activated outside of host infection, and (iii) the normal intestinal microbiota, which do not have the targeted virulence pathways, should be unharmed. We chose to utilize two phenotypic assays, inhibition of Shigella survival in macrophages and Shigella growth inhibition (minimum inhibitory concentration), to interrogate the 1.7 M compound screening collection subset of the GlaxoSmithKline drug discovery chemical library. A number of secondary assays on the hit compounds resulting from the primary screens were conducted, which, in combination with chemical, structural, and physical property analyses, narrowed the final hit list to 44 promising compounds for further drug discovery efforts. The rapid development of antibiotic resistance is a critical problem that has the potential of returning the world to a "pre-antibiotic" type of environment, where millions of people will die from previously treatable infections. One relatively newer approach to minimize the selection pressures for the development of resistance is to target virulence pathways. This is anticipated to eliminate any resistance selection pressure in environmental exposure to virulence-targeted antibiotics and will have the added benefit of not affecting the non-virulent microbiome. This paper describes the development and application of a simple, reproducible, and sensitive assay to interrogate an extensive chemical library in high-throughput screening format for activity against the survival of Shigella flexneri 2457T-nl in THP-1 macrophages. The ability to screen very large numbers of compounds in a reasonable time frame (~1.7 M compounds in ~8 months) distinguishes this assay as a powerful tool in further exploring new compounds with intracellular effect on S. flexneri or other pathogens with similar pathways of pathogenesis. The assay utilizes a luciferase reporter which is extremely rapid, simple, relatively inexpensive, and sensitive and possesses a broad linear range. The assay also utilized THP-1 cells that resemble primary monocytes and macrophages in morphology and differentiation properties. THP-1 cells have advantages over human primary monocytes or macrophages because they are highly plastic and their homogeneous genetic background minimizes the degree of variability in the cell phenotype (1). The intracellular and virulence-targeted selectivity of our methodology, determined via secondary screening, is an enormous advantage. Our main interest focuses on hits that are targeting virulence, and the most promising compounds with adequate physicochemical and drug metabolism and pharmacokinetic (DMPK) properties will be progressed to a suitable in vivo shigellosis model to evaluate the therapeutic potential of this approach. Additionally, compounds that act via a host-directed mechanism could be a promising source for further research given that it would allow a whole new, specific, and controlled approach to the treatment of diseases caused by some pathogenic bacteria.

N-Functionalized fluorophores: detecting urinary albumin and imaging lipid droplets

A series of novel N-sulfonyl pyridinium fluorophores were designed, synthesized, and explored in terms of their ability to bind with serum albumins. Upon binding the fluorophores with BSA, noticeable emission wavelength or intensity changes accompanied by color changes were observed. Competitive binding studies revealed that the fluorophore selectively binds to the warfarin site, but the binding affinity also depends on the nature of the scaffold. Additionally, the fluorophores were employed to detect spiked serum albumin in artificial urine. Cellular imaging experiments indicated that the fluorophores accumulate within lipid droplets (LDs), suggesting their potential as promising biomarkers for lipid droplets. Furthermore, the fluorescence intensity, number, and size of LDs increased upon serum starvation.

Ring Expansion Strategies for the Synthesis of Medium Sized Ring and Macrocyclic Sulfonamides

Two new ring expansion strategies are reported for the synthesis of medium sized ring and macrocyclic sulfonamides. Both methods can be performed without using classical protecting groups, with the key ring expansion step initiated by nitro reduction and amine conjugate addition respectively. Each method can be used to make diversely functionalised cyclic sulfonamides in good to excellent yields, in a range of ring sizes. The ring size dependency of the synthetic reactions is in good agreement with the outcomes modelled by Density Functional Theory calculations.

Novel Benzo[a]phenoxazinium Chlorides Functionalized with Sulfonamide Groups as NIR Fluorescent Probes for Vacuole, Endoplasmic Reticulum, and Plasma Membrane Staining

The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.

Novel asymmetrical azines appending 1,3,4-thiadiazole sulfonamide: synthesis, molecular structure analyses, in silico ADME, and cytotoxic effect†

Toward finding potential and novel anticancer agents, we designed and prepared novel differently substituted unsymmetrical azine-modified thiadiazole sulfonamide derivatives using the “combi-targeting approach”. An efficient procedure for synthesizing the designed compounds starts with 5-acetyl-3-N-(4-sulfamoylphenyl)-2-imino-1,3,4-thiadi-azoline 4. The E/Z configuration for compound 5 was investigated based on spectral analysis combined with quantum mechanical calculation applying the DFT-B3LYP method and 6-31G(d) basis set. The computational results found that the E isomer was energetically more favorable than the Z isomer by 2.21 kcal mol⁻¹. Moreover, ¹H and ¹³C chemical shifts for the E and Z isomers in DMSO were predicted using the GIAO-B3LYP/6-31G(d) computations and IEF-PCM solvation model. The computed chemical shifts for both isomers are consistent with those observed experimentally, indicating that they exist in the solution phase. Moreover, the E/Z configuration for the synthesized azines 7a–c, 9, 11, 13, 15a and 15b was also studied theoretically using the DFT-B3LYP/6-31G(d) calculations. In silico prediction for the biological activities was reported regarding the HOMO–LUMO energy gaps and molecular reactivity descriptors besides the ADMT/drug-likeness properties. The cytotoxic effect of the synthesized compounds has been assayed via the determination of their IC₅₀.

Toward finding potential and novel anticancer agents, we designed and prepared novel differently substituted unsymmetrical azine-modified thiadiazole sulfonamide derivatives using the “combi-targeting approach”.

Synthesis, Physicochemical Properties and Molecular Docking of New Benzothiazole Derivatives as Antimicrobial Agents Targeting DHPS Enzyme

The drug-resistance problem is widely spread and becoming more common in community-acquired and nosocomial strains of bacteria. Therefore, finding new antimicrobial agents remains an important drug target. From this perspective, new derivatives of benzothiazole were synthesized and evaluated for their antimicrobial activity and ability to inhibit the DHPS enzyme. The synthesis was carried out by the reaction of benzothiazole N-arylsulphonylhydrazone with N-aryl-2-cyano-3-(dimethylamino)acrylamide, N-aryl-3-(dimethylamino)prop-2-en-1-one, arylaldehydes or diazonium salt of arylamine derivatives, which led to the formation of N-arylsulfonylpyridones 6a-d (yield 60-70%) and 12a-c (yield 50-60%),N-(2-(benzo[d]thiazole-2-yl)-3-arylacryloyl-4-methylsulfonohydrazide 14a-c (yield 60-65%), 4-(benzo[d]thiazole-2-yl)-5-aryl-1H-pyrazol-3(2H)-one 16a-c (yield 65-75%), and N'-(2-(benzo[d]thiazol-2-yl)-2-(2-arylhydrazono)acetyl)-4-arylsulfonohydrazide 19a-e (yield 85-70%). The antimicrobial evaluations resulted into a variety of microbial activities against the tested strains. Most compounds showed antimicrobial activity against S. aureus with an MIC range of 0.025 to 2.609 mM. The most active compound, 16c, exhibited superior activity against the S. aureus strain with an of MIC 0.025 mM among all tested compounds, outperforming both standard drugs ampicillin and sulfadiazine. The physicochemical-pharmacokinetic properties of the synthesized compounds were studied, and it was discovered that some compounds do not violate rule of five and have good bioavailability and drug-likeness scores. The five antimicrobial potent compounds with good physicochemical-pharmacokinetic properties were then examined for their inhibition of DHPS enzyme. According to the finding, three compounds, 16a-c, had IC₅₀ values comparable to the standard drug and revealed that compound 16b was the most active compound with an IC₅₀ value of 7.85 μg/mL, which is comparable to that of sulfadiazine (standard drug) with an IC₅₀ value of 7.13 μg/mL. A docking study was performed to better understand the interaction of potent compounds with the binding sites of the DHPS enzyme, which revealed that compounds 16a-c are linked by two arene-H interactions with Lys220 within the PABA pocket.

Copper-Catalyzed, Aerobic Synthesis of NH-Sulfonimidamides from Primary Sulfinamides and Secondary Amines

NH-Sulfonimidamides are prepared by copper-catalyzed coupling of primary sulfinamides with secondary amines. Neither a ligand nor an additive is needed, and air is the terminal oxidant. The reactions occur at room temperature, show good functional group tolerance, and lead to products in good yields. A sulfanenitrile is proposed as an intermediate in this oxidative amination.

Synthesis of novel pyridine and pyrimidine thioglycoside phosphoramidates for the treatment of COVID-19 and influenza A viruses

A novel series of pyridine, cytosine, and uracil thioglycoside analogs (4a-i, 9a,b, and 13a,b, respectively) and their corresponding phosphoramidates (6a-I, 10a,b, and 14a,b, respectively) were synthesized and assessed for their antiviral inhibitory activities in a dual-pathogen screening protocol against SARS-CoV-2 and influenza A virus (IAV). MTT cytotoxicity (TC50) and plaque reduction assays were used to explore inhibition and cytotoxicity percentage values for H5N1 influenza virus strain and the half-maximal cytotoxic concentration (CC₅₀) and inhibitory concentration (IC₅₀) for SARS-CoV-2 virus. Most of the tested compounds demonstrated dose-dependent inhibition behavior. Both cytosine thioglycoside phosphoramidates 10a and 10b exhibited the most potent profiles with 83% and 86% inhibition at 0.25 µM concentration against H5N1 and IC₅₀ values of 12.16 µM, 14.9 µM against SARS-CoV-2, respectively. Moreover, compounds 10a and 10b have been shown to have the highest selectivity index (SI) among all the tested compounds against SARS-CoV-2 with 28.2 and 26.9 values, respectively.

Synthesis, Characterization and Biological Evaluation of Novel Thiourea Derivatives

Objective: A new series of 4-[3-(substitutedphenyl)thioureido]-N-(6-chloropyrazin-2-yl)benzenesulfonamide were synthesized from sulfaclozine. Methods: All compounds were characterized by IR, 1H-NMR spectroscopic methods and elemental analysis. In addition to the antioxidant activity of the synthesis series, enzyme inhibition activities such as anticholinesterase, tyrosinase, α-amylase and α-glycosidase were determined for the first time in this study. Results: According to these biological activity test results, compound 2a in the DPPH, 2c in the ABTS˙+ assay exhibited more antioxidant activity than reference standard. All thiourea derivatives demonstrated good BChE inhibitory activity than galantamine. Among the compounds, 2e and 2f showed the best tyrosinase enzyme inhibition activity, while 2g had the best α-amylase and α-glucosidase enzyme inhibition activity. In addition, we evaluated the druglikeness properties of compounds and their oral bioavailability were also found to be high. Conclusion: Thiourea derivatives exhibited remarkable antioxidant activity and enzyme inhibition activity against tyrosinase, cholinesterase, α-amylase and α-glucosidase.

Exploring Electrochemical C(sp3)-H Oxidation for the Late-Stage Methylation of Complex Molecules

The "magic methyl" effect, a dramatic boost in the potency of biologically active compounds from the incorporation of a single methyl group, provides a simple yet powerful strategy employed by medicinal chemists in the drug discovery process. Despite significant advances, methodologies that enable the selective C(sp3)-H methylation of structurally complex medicinal agents remain very limited. In this work, we disclose a modular, efficient, and selective strategy for the α-methylation of protected amines (i.e., amides, carbamates, and sulfonamides) by means of electrochemical oxidation. Mechanistic analysis guided our development of an improved electrochemical protocol on the basis of the classic Shono oxidation reaction, which features broad reaction scope, high functional group compatibility, and operational simplicity. Importantly, this reaction system is amenable to the late-stage functionalization of complex targets containing basic nitrogen groups that are prevalent in medicinally active agents. When combined with organozinc-mediated C-C bond formation, our protocol enabled the direct methylation of a myriad of amine derivatives including those that have previously been explored for the "magic methyl" effect. This synthesis strategy thus circumvents multistep de novo synthesis that is currently necessary to access such compounds and has the potential to accelerate drug discovery efforts.

Synthesis of triarylpyridines with sulfonate and sulfonamide moieties via a cooperative vinylogous anomeric-based oxidation

Herein, novel magnetic nanoparticles with pyridinium bridges namely Fe3O4@SiO2@PCLH-TFA through a multi-step pathway were designed and synthesized. The desired catalyst and its corresponding precursors were characterized with different techniques such as Fourier transform infrared (FT-IR) spectroscopy, 1H NMR, 13C NMR, Mass spectroscopy, energy dispersive X-ray (EDX) analysis, thermogravimetric/derivative thermogravimetry (TG/DTG) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). In addition, the catalytic application of the prepared catalyst in the synthesis of new series of triarylpyridines bearing sulfonate and sulfonamide moieties via a cooperative vinylogous anomeric-based oxidation was highlighted. The current trend revealed that the mentioned catalyst shows high recoverability in the reported synthesis.

Crystal structure of ethyl 2-(3-amino-5-oxo-2-tosyl-2,5-di-hydro-1H-pyrazol-1-yl)acetate

In the title compound, C14H17N3O5S, the five-membered ring is essentially planar. The substituents at the nitro-gen atoms subtend a C-N-N-S torsion angle of -95.52 (6)°. The amino group forms an intra-molecular hydrogen bond to a sulfonyl oxygen atom; two inter-molecular hydrogen bonds from the amino group, to the other S=O group and to the oxo substituent, form a layer structure parallel to the ab plane. The structure determination confirms that the title compound is N- rather than O-alkyl-ated.

Novel Synthesis and Antiviral Evaluation of New Benzothiazole-Bearing N-Sulfonamide 2-Pyridone Derivatives as USP7 Enzyme Inhibitors

In this article, a series of benzothiazole-bearing N-sulfonamide 2-pyridone derivatives were synthesized via the reaction of benzothiazole sulfonylhydrazide with sodium salts of both (hydroxymethylene) cycloalkanones and unsaturated ketones, as well as ethoxymethylene derivatives. The structures of the resultant compounds were confirmed using IR, ¹H NMR, ¹³C NMR, ¹H-¹H correlation spectroscopy (COSY), ¹H-¹³C heteronuclear multiple bond coherence (HMBC), and ¹H-¹³C heteronuclear multiple quantum coherence (HSQC) spectral analysis and elemental analysis. The newly synthesized compounds were evaluated in vitro for their antiviral activities against the HSV-1, HAV HM175, HCVcc genotype 4, CBV4, and HAdV7 viruses. Additionally, the compounds were examined for their cytotoxic effect on five normal cell lines. It was observed that five compounds were found to possess viral reduction of 50% or more against CBV4 with significant IC₅₀, CC₅₀, and SI values. In the case of HSV-1 and HAV HM175 viruses, three compounds have shown more than 50% reduction, while in the case of HCVcc genotype 4 and HAdV7 viruses, only two compounds demonstrated more than 50% reduction. Furthermore, the physicochemical properties of the most active compounds were evaluated. The two most potent compounds against HSV-1 virus, 7e and 13a, were evaluated for their inhibitory activity against USP7. Docking studies using Molecular Operating Environment (MOE) were used to identify the interactions between 7e and 13a compounds and the active site of the USP7 enzyme.

Design and Synthesis of a New Class of Pyridine-Based N-Sulfonamides Exhibiting Antiviral, Antimicrobial, and Enzyme Inhibition Characteristics

A new strategy for designing and assembling a novel class of functionalized pyridine-based benzothiazole and benzimidazole incorporating sulfonamide moieties was developed. The synthesis was carried out by reacting N-cyanoacetoarylsulfonylhydrazide with various electrophiles such as 2-(benzo[d]thiazol-2-yl)-3,3-bis(alkylthio)acrylonitriles and 2-(benzo[d]imidazol-2-yl)-3,3-bis(methylthio)-acrylonitriles, as well as 2-ethoxyl acrylonitrile derivatives. The synthesized compounds were tested for their antiviral and antimicrobial potency. Two of the synthesized compounds, 15c and 15d, showed more than 50% viral reduction against HSV-1 and CBV4, with significant IC₅₀ and CC₅₀ values. The two potent compounds 15c and 15d have also shown inhibitory activity against Hsp90α protein with IC₅₀ values of 10.24 and 4.48 μg/mL, respectively. A combination of 15c and 15d with acyclovir has led to IC₅₀ values that are lower than that of acyclovir alone. Molecular modeling studies were used to identify the interactions between the 15c and 15d compounds and the active site of Hsp90α enzyme. The antimicrobial investigation of the new compounds has also shown that 8b and 15d exhibited a higher inhibition zone (IZ) than sulfadiazine and gentamicin against Klebsiella pneumonia, whereas 9a showed higher IZ than ampicillin against Staphylococcus aureus. According to the enzyme assay study on dihydrofolate reductase, 9a was shown to be the most potent compound among all examined compounds.

Tailored-design of electrospun nanofiber cellulose acetate/poly(lactic acid) dressing mats loaded with a newly synthesized sulfonamide analog exhibiting superior wound healing

To effectively allow for controlled release of a newly synthesized sulfonamide analog, biodegradable poly(lactic acid) nanofibrous dressing mats tailored-designed for maximum wound healing efficacy were developed. The heterocyclic analog, N-(3,4-diamino-7-(benzo [d]thiazol-2-yl)-6-oxo-1H-pyrazolo[4,3-c]pyridin-5(6H)-yl)benzenesulfonamide, has been specifically synthesized to possess superior antibacterial and anti-inflammatory characteristics. Hydrophilic cellulose acetate and/or poly(ethylene oxide) were blended with the hydrophobic PLA to control the hydrophilicity/hydrophobicity ratio for the sustained release of the drug. SEM detected no drug crystals on the surface of the nanofibers confirming the homogeneous dispersion and compatibility of the drug with the nanofibers. BET indicated almost-reversible Type II sorption isotherms. The swelling studies revealed that the presence of hydrogen bonds between the hydroxyl groups of CA with the carbonyl ester groups of PLA limited the ability of CA molecules to leach from the polymer matrix. Water vapor permeability were all determined to be within the range of 15-19 g/m²/h. In-vitro cell viability and cell proliferation studies revealed the superiority of the fabricated dressing mats in terms of its bioactivity and cellular interaction. In-vivo studies confirmed the major improvement in its wound healing capabilities attributed to an enhanced epithelization, anti-inflammation, neo-angiogenesis, fibroplasias and collagen deposition that surpassed that of commercially available ones.

Design, Synthesis, and Antimicrobial Evaluation of a New Series of N-Sulfonamide 2-Pyridones as Dual Inhibitors of DHPS and DHFR Enzymes

Sulfonamides and trimethoprim (TMP) drugs are normally used to inhibit the action of dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) enzymes, respectively. In this work, a new series of N-sulfonamide 2-pyridone derivatives that combine the inhibitory activities of DHPS and DHFR into one molecule were synthesized and evaluated for its in vitro antimicrobial activity and the ability to inhibit the action of both enzymes simultaneously. The synthesis was carried out via the reaction of novel benzothiazol sulfonylhydrazide with ketene dithioacetal derivatives, and the structures of the resultant compounds were confirmed using spectral and elemental techniques. Among the synthesized compounds, five compounds 3b, 5a, 5b, 11a, and 11b were found to possess significant antimicrobial activities against tested bacterial and fungi strains. The compounds were also examined for their cytotoxicity on HFB4 human dermal fibroblast cell line using MTT assay. The in vitro enzyme assay study of these compounds against DHPS and DHFR enzymes showed that compound 11a was the most potent inhibitor against both enzymes with IC₅₀ values of 2.76 and 0.20 μg/mL, respectively. Docking studies showed that this compound has occupied both the p-aminobenzoic acid and pterin binding pockets of DHPS as well as the pterin binding pocket of DHFR. The results of these investigations confirmed that compound 11a is the most potent dual DHPS/DHFR inhibitor.

Crystal structure of ethyl 2-(5-amino-1-benzene-sulfonyl-3-oxo-2,3-di-hydro-1H-pyrazol-2-yl)acetate

In the title compound, C13H15N3O5S, the two rings face each other in a 'V' form at the S atom, with one N-H⋯O=S and one C-H⋯O=S contact from the pyrazolyl substituents to the sulfonyl group. Two classical hydrogen bonds from the amine group, one of the form N-H⋯O=S and one N-H⋯O=Coxo, link the mol-ecules to form layers parallel to the bc plane.

Efficient Synthesis and Docking Studies of Novel Benzothiazole-Based Pyrimidinesulfonamide Scaffolds as New Antiviral Agents and Hsp90α Inhibitors

A series of novel substituted 2-pyrimidylbenzothiazoles incorporating either sulfonamide moieties or the amino group at C2 of the pyrimidine ring were synthesized and evaluated for its antiviral potency. The novel synthesis of the ring system was carried out by reacting guanidine or N-arylsulfonated guanidine with different derivatives of ylidene benzothiazole based on Michael addition pathways. The antiviral activity of the newly synthesized compounds was examined by a plaque reduction assay against HSV-1, CBV4, HAV HM 175, HCVcc genotype 4 viruses, and HAdV7. In the case of HSV-1, it was determined that 5 out of the 21 synthesized compounds exhibited superior viral reduction in the range of 70-90% with significant IC₅₀, CC₅₀, and SI values as compared with acyclovir. In the case of CBV4, nine compounds have shown more than 50% reduction. Comparable results were obtained for seven of these synthesized compounds when evaluated against HAV with only a couple of them showing 50% reduction or more against HCVcc genotype 4. Remarkably, one compound, 9a, has shown broad action against all five examined viruses, rendering it as potentially an effective antiviral agent. The five potent compounds 9a, 9b, 14b, 14g, and 14h against HSV-1 have also presented inhibitory activity against the Hsp90α protein with IC₅₀ in the range of 4.87-10.47 μg/mL. Interestingly, a combination of the potent synthesized compounds with acyclovir led to IC₅₀ values lower than that of acyclovir alone. The potent compounds 9a, 9b, 14b, 14g, and 14h were also docked inside the active site of Hsp90α to assess the interaction pattern between the tested compounds and the active site of the protein.