Synthesis, molecular modelling, and antibacterial evaluation of new sulfonamide-dyes based pyrrole compounds

In this study, we synthesized new series of 5-oxo-2-phenyl-4-(arylsulfamoyl)sulphenyl) hydrazono)-4,5-dihydro-1H-pyrrole-3-carboxylate hybrids 4a-f with the goal of overcoming sulfonamide resistance and identifying novel therapeutic candidates by chemical changes. The chemical structures of the synthesized hybrids were established over the spectroscopic tools. The frontier molecular orbitals configuration and energetic possessions of the synthesized compounds were discovered utilizing DFT/B3LYP/6-311++ G** procedure. The 3D plots of both HOMO and LUMO showed comparable configuration of both HOMO and LUMO led to close values of their energies. Amongst the prepared analogues, the sulfonamide hybrids 4a-f, hybrid 4a presented potent inhibitory towards S. typhimurium with (IZD = 15 mm, MIC = 19.24 µg/mL) and significant inhibition with (IZD = 19 mm, MIC = 11.31 µg/mL) against E.coli in contrast to sulfonamide (Sulfamethoxazole) reference Whereas, hybrid 4d demonstrated potent inhibition with (IZD = 16 mm, MIC = 19.24 µg/mL) against S. typhimurium with enhanced inhibition against E. Coli, Additionally, the generated sulfonamide analogues'' molecular docking was estimated over (PDB: 3TZF and 6CLV) proteins. Analogue 4e had the highest documented binding score as soon as linked to the other analogues. The docking consequences were fitting and addressed with the antibacterial valuation.

Novel sulfonamide derivatives as a tool to combat methicillin-resistant Staphylococcus aureus

Increasing resistance in Staphylococcus aureus has created a critical need for new drugs, especially those effective against methicillin-resistant strains (methicillin-resistant Staphylococcus aureus [MRSA]). Sulfonamides are a privileged scaffold for the development of novel antistaphylococcal agents. This review covers recent advances in sulfonamides active against MRSA. Based on the substitution patterns of sulfonamide moieties, its derivatives can be tuned for desired properties and biological activity. Contrary to the traditional view, not only N-monosubstituted 4-aminobenzenesulfonamides are effective. Novel sulfonamides have various mechanisms of action, not only 'classical' inhibition of the folate biosynthetic pathway. Some of them can overcome resistance to classical sulfa drugs and cotrimoxazole, are bactericidal and active in vivo. Hybrid compounds with distinct bioactive scaffolds are particularly advantageous.

Synthesis, biological assessment, and computational investigations of nifedipine and monastrol analogues as anti-leishmanial major and anti-microbial agents

Leishmaniasis includes a range of parasitic diseases caused by numerous types of the protozoan kinetoplastid parasite. Fungal and bacterial pathogens have led to infectious illnesses causing some main public health problem in current years. A series of dihydropyridine and tetrahydropyrimidine derivatives having fluoro, bromo, and nitro substituents at para-phenyl ring on C4 of dihydropyridine and tetrahydropyrimidine rings were synthesized. Then, anti-leishmanial and antimicrobial potencies of compounds were assessed. All compounds were synthesized via Hantzsch and Biginelli reactions. All derivatives were evaluated for their anti-leishmanial and antimicrobial activities. Moreover, docking and molecular dynamics simulation calculations of the compounds in PRT1 binding site were performed to report the results of anti-leishmanial and antimicrobial activities. Compounds 4a and 4b showed the highest anti-amastigote and anti-promastigote activities. Compound 4a revealed the highest antimicrobial activity against E. coli, P. aeruginosa, and C. albicans strains. In addition, compound 4c showed the highest activity against S. aureus. The fluoro, bromo, and nitro substituents in para-position of phenyl group at C4 of dihydropyridine and tetrahydropyrimidine moieties as well as the bulk and length of the chain linking to the ester moieties are essential for anti-leishmanial and anti-microbial activities of these derivatives. Low cytotoxicity was shown by most of derivatives against macrophages. The molecular docking studies were in agreement with in vitro assay. Moreover, hydrogen binds, RMSF, RMSD, and Rg, strongly showed the steady binding of 4a and 4b compounds in PRT1 active site.

New Copper Complexes with Antibacterial and Cytotoxic Activity

The discovery of a new non-toxic metal complex with biological activity represents a very active area of research. Two Cu+2 complexes, [Cu4(L1)4(OH)4(DMF)2(H2O)] (C1) (HL1 = N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)-benzenesulfonamide) and [Cu(L2)2(phen)(H2O)] (C2) (HL2 = N-(5-(4-methylphenyl)-[1,3,4]-thiadiazole-2-yl)-naphtalenesulfonamide), with two new ligands were synthesized. The X-ray crystal structures of the complexes were determined. In both complexes, Cu+2 is five-coordinated, forming a CuN2O3 and CuN4O chromophore, respectively. The ligands act as monodentate, coordinating the metal ion through a single Nthiadiazole atom; for the two complexes, the molecules from the reaction medium (phenantroline, dimethylformamide and water) are also involved in the coordination of Cu+2. The complexes have a distorted square pyramidal square-planar geometry. The compounds were characterized by FT-IR and UV-Vis spectroscopy. Using the microdilution method, the antibacterial activity of the complexes was determined against four Gram-positive and two Gram-negative bacteria, with Gentamicin as the positive control. Cytotoxicity studies were carried out on two tumor cell lines (HeLa, DLD-1) and on a normal cell line (HFL1) using the MTT method and Cisplatin as a positive control. Flow cytometric assessment of apoptosis induced by the complexes on the three cell lines was also performed. Both complexes present in vitro biological activities but complex C2 is more active.

Halogen Bonding in Sulphonamide Co-Crystals: X···π Preferred over X···O/N?

Sulphonamides have been one of the major pharmaceutical compound classes since their introduction in the 1930s. Co-crystallisation of sulphonamides with halogen bonding (XB) might lead to a new class of pharmaceutical-relevant co-crystals. We present the synthesis and structural analysis of seven new co-crystals of simple sulphonamides N-methylbenzenesulphonamide (NMBSA), N-phenylmethanesulphonamide (NPMSA), and N-phenylbenzenesulphonamide (BSA), as well as of an anti-diabetic agent Chlorpropamide (CPA), with the model XB-donors 1,4-diiodotetrafluorobenzene (14DITFB), 1,4-dibromotetrafluorobenzene (14DBTFB), and 1,2-diiodotetrafluorobenzene (12DITFB). In the reported co-crystals, X···O/N bonds do not represent the most common intermolecular interaction. Against our rational design expectations and the results of our statistical CSD analysis, the normally less often present X···π interaction dominates the crystal packing. Furthermore, the general interaction pattern in model sulphonamides and the CPA multicomponent crystals differ, mainly due to strong hydrogen bonds blocking possible interaction sites.

Novel Sulfonamide Derivatives Containing a Piperidine Moiety as New Bactericide Leads for Managing Plant Bacterial Diseases

Plant bacterial diseases are an intractable problem due to the fact that phytopathogens have acquired strong resistances for traditional pesticides, resulting in restricting the quality and yield of agricultural products around the world. To develop new agrochemical alternatives, we prepared a novel series of sulfanilamide derivatives containing piperidine fragments and assessed their antibacterial potency. The bioassay results revealed that most molecules displayed excellent in vitro antibacterial potency towards Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac). In particular, molecule C₄ exhibited outstanding inhibitory activity toward Xoo with EC₅₀ value of 2.02 µg mL^-1, which was significantly better than those of the commercial agents bismerthiazol (EC₅₀ = 42.38 µg mL^-1) and thiodiazole copper (EC₅₀ = 64.50 µg mL^-1). A series of biochemical assays confirmed that compound C₄ interacted with dihydropteroate synthase, and irreversibly damaged the cell membrane. In vivo assays showed that the molecule C₄ presented acceptable curative and protection activities of 34.78% and 39.83%, respectively, at 200 µg mL^-1, which were greater than those of thiodiazole and bismerthiazol. This study highlights the valuable insights for the excavation and development of new bactericides that can concurrently target dihydropteroate synthase and bacterial cell membranes.

Application of Drug Aggregation to Solubilize Antimicrobial Compound and Enhancing its Bioavailability

With the progress and advancement in discovery of novel antimicrobial drugs, efficient solubility plays an important component for a drug to express its out-turn effectively. A biocompatible neutral/non-ionic surfactant, Triton X-100 (Tx-100), was successfully employed to solubilize an antibiotic drug, sulfamethazine (SMZ), through micellization process. The association process of Tx-100 toward SMZ was confirmed through the characteristic spectral change in absorption and emission spectroscopy. The morphological behavior of the complex was studied from small angle neutron scattering (SANS). Changes in size(s) and charge(s) of the micelles were monitored using zeta (z) potential technique. This present study emphasized the molecular mechanism and characteristics of Tx-100 as an effective drug solubilizing and carrier agent. Thus, the drug-loaded micellar system can enhance cellular uptake and increase the antibacterial effects of drugs in the biological system(s). Schematic illustration of drug-surfactant micelle formation and target release of drug at the targeted site.

Bacterial Pathogens in the Food Industry: Antibiotic Resistance and Virulence Factors of Salmonella enterica Strains Isolated from Food Chain Links

Salmonella is one of the most important foodborne pathogens. Fifty-three strains of Salmonella deposited in the Culture Collection of Industrial Microorganisms-Microbiological Resources Center (IAFB) were identified using molecular and proteomic analyses. Moreover, the genetic similarity of the tested strains was determined using the PFGE method. Main virulence genes were identified, and phenotypical antibiotic susceptibility profiles and prevalence of resistance genes were analyzed. Subsequently, the occurrence of the main mechanisms of β-lactam resistance was determined. Virulence genes, invA, fimA, and stn were identified in all tested strains. Phenotypic tests, including 28 antibiotics, showed that 50.9% of the strains were MDR. The tet genes associated with tetracyclines resistance were the most frequently identified genes. Concerning the genes associated with ESBL-producing Salmonella, no resistance to the TEM and CTX-M type was identified, and only two strains (KKP 1597 and KKP 1610) showed resistance to SHV. No strains exhibited AmpC-type resistance but for six Salmonella strains, the efflux-related resistance of PSE-1 was presented. The high number of resistant strains in combination with multiple ARGs in Salmonella indicates the possible overuse of antibiotics. Our results showed that it is necessary to monitor antimicrobial resistance profiles in all food chain links constantly and to implement a policy of proper antibiotic stewardship to contain or at least significantly limit the further acquisition of antibiotic resistance among Salmonella strains.

Silatrane-Sulfonamide Hybrids as Promising Antibacterial Agents

At the A. E. Favorsky Irkutsk Institute of Chemistry, a series of silatrane-sulfonamide hybrids 1a-d and 2a-d was synthesized. The antibacterial activity of 1a, 1b, 1d, 2a, and 2b against test strains of bacteria Yersinia pestis EV NIIEG, Yersinia enterocolitica 628/1, Listeria monocytogenes 766, and Starhylococcus aureus ATCC 6538-P (FDA 209-Р) was evaluated. The minimum inhibitory concentration for silatrane-sulfonamide hybrids was 100-200 mg/liter. Silatrane-sulfonamide hybrid 1d was the most active against all tested strains: minimum inhibitory concentration 100 mg/liter. Exposure to silatrane-sulfonamide hybrids in a doses of 100-200 mg/liter inhibited culture growth by 50-75%.

Urea derivatives carrying a thiophenylthiazole moiety: Design, synthesis, and evaluation of antitubercular and InhA inhibitory activities

The recent emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb) has complicated and significantly slowed efforts to eradicate and/or reduce the worldwide incidence of life-threatening acute and chronic cases of tuberculosis. To overcome this setback, researchers have increased the intensity of their work to identify new small-molecule compounds that are expected to remain efficacious antimicrobials against Mtb. Here, we describe our effort to apply the principles of molecular hybridization to synthesize 16 compounds carrying thiophene and thiazole rings beside the core urea functionality (TTU1-TTU16). Following extensive structural characterization, the obtained compounds were initially evaluated for their antimycobacterial activity against Mtb H37Rv. Subsequently, three derivatives standing out with their anti-Mtb activity profiles and low cytotoxicity (TTU5, TTU6, and TTU12) were tested on isoniazid-resistant clinical isolates carrying katG and inhA mutations. Additionally, due to their pharmacophore similarities to the well-known InhA inhibitors, the molecules were screened for their enoyl acyl carrier protein reductase (InhA) inhibitory potentials. Molecular docking studies were performed to support the experimental enzyme inhibition data. Finally, drug-likeness of the selected compounds was established by theoretical calculations of physicochemical descriptors.

Thiazole: A Versatile Standalone Moiety Contributing to the Development of Various Drugs and Biologically Active Agents

For many decades, the thiazole moiety has been an important heterocycle in the world of chemistry. The thiazole ring consists of sulfur and nitrogen in such a fashion that the pi (π) electrons are free to move from one bond to other bonds rendering aromatic ring properties. On account of its aromaticity, the ring has many reactive positions where donor–acceptor, nucleophilic, oxidation reactions, etc., may take place. Molecules containing a thiazole ring, when entering physiological systems, behave unpredictably and reset the system differently. These molecules may activate/stop the biochemical pathways and enzymes or stimulate/block the receptors in the biological systems. Therefore, medicinal chemists have been focusing their efforts on thiazole-bearing compounds in order to develop novel therapeutic agents for a variety of pathological conditions. This review attempts to inform the readers on three major classes of thiazole-bearing molecules: Thiazoles as treatment drugs, thiazoles in clinical trials, and thiazoles in preclinical and developmental stages. A compilation of preclinical and developmental thiazole-bearing molecules is presented, focusing on their brief synthetic description and preclinical studies relating to structure-based activity analysis. The authors expect that the current review may succeed in drawing the attention of medicinal chemists to finding new leads, which may later be translated into new drugs.

Sulfonamide-Derived Dithiocarbamate Gold(I) Complexes Induce the Apoptosis of Colon Cancer Cells by the Activation of Caspase 3 and Redox Imbalance

Two new families of dithiocarbamate gold(I) complexes derived from benzenesulfonamide with phosphine or carbene as ancillary ligands have been synthesized and characterized. In the screening of their in vitro activity on human colon carcinoma cells (Caco-2), we found that the more lipophilic complexes—those with the phosphine PPh₃—exhibited the highest anticancer activity whilst also displaying significant cancer cell selectivity. [Au(S₂CNHSO₂C₆H₅)(PPh₃)] (1) and [Au(S₂CNHSO₂-p-Me-C₆H₄)(IMePropargyl)] (8) produce cell death, probably by intrinsic apoptosis (mitochondrial membrane potential modification) and caspase 3 activation, causing cell cycle arrest in the G1 phase with p53 activation. Besides this, both complexes might act as multi-target anticancer drugs, as they inhibit the activity of the enzymes thioredoxin reductase (TrxR) and carbonic anhydrase (CA IX) with the alteration of the redox balance, and show a pro-oxidant effect.

Biophysical and molecular modeling evidences for the binding of sulfa molecules with hemoglobin

The molecular mechanism of the heme protein, hemoglobin (Hb) interaction with sulfa molecule, sulfadiazine (SDZ) has been investigated through spectroscopic, neutron scattering and molecular modeling techniques. Absorption and emission spectroscopic studies showed that SDZ molecules were bound to Hb protein, non-cooperatively. The binding affinityof SDZ-Hb complex at standard experimental condition was evaluated to be around (4.2 ± 0.07) ×10⁴, M^-1with 1:1 stoichiometry. Drug induced structural perturbation of the 3 D protein moiety was confirmed through circular dichroism (CD), synchronous fluorescence and small angle neutron scattering methods. From the temperature dependent spectrofluorometric studies, the negative standard molar Gibbs energy change suggested the spontaneity of the reaction. The negative enthalpy and positive entropy change(s) indicated towards the involvement of both electrostatic and hydrophobic forces during the association process. Salt dependent fluorescence study revealed major contributions from non-poly-electrolytic forces. Molecular modeling studies determined the probable binding sites, types of interaction involved and the conformational alteration of the compactness of the Hb structure upon interaction with SDZ molecule. Overall, the study provides detailed insights into the binding mechanism of SDZ antibiotics to Hb protein.Communicated by Ramaswamy H. Sarma.

Synthesis, DFT Analysis, and Evaluation of Antibacterial and Antioxidant Activities of Sulfathiazole Derivatives Combined with In Silico Molecular Docking and ADMET Predictions

Synthetic modifications of sulfathiazole derivatives become an interesting approach to enhance their biological properties in line with their applications. As a result, sulfathiazole derivatives become a good candidate and potential class of organic compounds to play an important role towards medicinal chemistry. In present study, one thiazole derivative and two new sulfathiazole derivatives are synthesized with 94% and 72–81% yields, respectively. Furthermore, the synthesized compounds were evaluated for their in vitro antibacterial activity against two Gram-negative (E. coli and P. aeruginosa) and two Gram-positive bacterial strains (S. pyogenes and S. aureus) by disk diffusion method. Among synthesized compounds, compound 11a showed potent inhibitory activity against Gram-negative, E. coli with 11.6 ± 0.283 mm zone of inhibition compared to standard drug sulfamethoxazole (15.7 ± 0.707 mm) at 50 mg/mL. The radical scavenging activities of these compounds were evaluated using DPPH radical assay, and compound 11a showed the strongest activity with IC₅₀ values of 1.655 μg/mL. The synthesized compounds were evaluated for their in silico molecular docking analysis using S. aureus gyrase (PDB ID: 2XCT) and human myeloperoxidase (PDB ID: 1DNU) and were found to have minimum binding energy ranging from −7.8 to −10.0 kcal/mol with 2XCT and −7.5 to −9.7 with 1DNU. Compound 11a showed very good binding score −9.7 kcal/mol with both of the proteins and had promising alignment with in vitro results. Compound 11b also showed high binding scores with both proteins. Drug likeness and ADMET of synthesized compounds were predicted. The DFT analysis of synthesized compounds was performed using Gaussian 09 and visualized through Gauss view 6.0. The structural coordinates of the lead compounds were optimized using B3LYP/6–31 G (d,p) level basis set without any symmetrical constraints. Studies revealed that all the synthesized compounds might be candidates for further antibacterial and antioxidant studies.

Stimulation of Sulfonamides Antibacterial Drugs Activity as a Result of Complexation with Ru(III): Physicochemical and Biological Study

Antibiotic resistance is a global problem, and one promising solution to overcome this issue is using metallodrugs, which are drugs containing metal ions and ligands. These complexes are superior to free ligands in various characteristics including anticancer properties and mechanism of action. The pharmacological potential of metallodrugs can be modulated by the appropriate selection of ligands and metal ions. A good example of proper coordination is the combination of sulfonamides (sulfamerazine, sulfathiazole) with a ruthenium(III) ion. This work aimed to confirm that the activity of sulfonamides antibacterial drugs is initiated and/or stimulated by their coordination to an Ru(III) ion. The study determined the structure, electrochemical profile, CT-DNA affinity, and antimicrobial as well as anticancer properties of the synthesized complexes. The results proved that Ru(III) complexes exhibited better biological properties than the free ligands.