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ATP-competitive inhibitors of human DNA topoisomerase II show potential for becoming the successors of topoisomerase II poisons, the clinically successful anticancer drugs. Based on our recent screening hits, we designed, synthesized and biologically evaluated new, improved series of N-phenylpyrrolamide DNA topoisomerase II inhibitors. Six structural classes were prepared to systematically explore the chemical space of N-phenylpyrrolamide based inhibitors. The most potent inhibitor, 47d, had an IC50 value of 0.67 μM against DNA topoisomerase IIα. Compound 53b showed exceptional activity on cancer cell lines with IC50 values of 130 nM against HepG2 and 140 nM against MCF-7 cancer cell lines. The reported compounds have no structurally similarity to published structures, they are metabolically stable, have reasonable solubility and thus can serve as promising leads in the development of anticancer ATP-competitive inhibitors of human DNA topoisomerase IIα.

We have developed compounds with a promising activity against Acinetobacter baumannii and Pseudomonas aeruginosa, which are both on the WHO priority list of antibiotic-resistant bacteria. Starting from DNA gyrase inhibitor 1, we identified compound 27, featuring a 10-fold improved aqueous solubility, a 10-fold improved inhibition of topoisomerase IV from A. baumannii and P. aeruginosa, a 10-fold decreased inhibition of human topoisomerase IIα, and no cross-resistance to novobiocin. Cocrystal structures of 1 in complex with Escherichia coli GyrB24 and (S)-27 in complex with A. baumannii GyrB23 and P. aeruginosa GyrB24 revealed their binding to the ATP-binding pocket of the GyrB subunit. In further optimization steps, solubility, plasma free fraction, and other ADME properties of 27 were improved by fine-tuning of lipophilicity. In particular, analogs of 27 with retained anti-Gram-negative activity and improved plasma free fraction were identified. The series was found to be nongenotoxic, nonmutagenic, devoid of mitochondrial toxicity, and possessed no ion channel liabilities. Opis vira z dne 19. 1. 2023. Nasl. z nasl. zaslona. Bibliografija: str. 1423-1425. Abstract. ARRS, Farmacevtska kemija: načrtovanje, sinteza in vrednotenje učinkovin ARRS, MTAvsAMR: novi večtarčni antibiotiki proti večkratno odpornim bakterijam ARRS, Razvoj novih zaviralcev bakterijskih topoizomeraz za boj proti odpornim infekcijam iCASE studentship funded by BBSRC and Redx Pharma Plc Investigator Award from the Wellcome Trust BBSRC Institute Strategic Programme

A new series of dual low nanomolar benzothiazole inhibitors of bacterial DNA gyrase and topoisomerase IV were developed. The resulting compounds show excellent broad-spectrum antibacterial activities against Gram-positive Enterococcus faecalis, Enterococcus faecium and multidrug resistant (MDR) Staphylococcus aureus strains [best compound minimal inhibitory concentrations (MICs): range

Bacterial DNA gyrase and topoisomerase IV control the topological state of DNA during replication and represent important antibacterial drug targets. To be successful as drug candidates, newly synthesized compounds must possess optimal lipophilicity, which enables efficient delivery to the site of action. In this study, retention behavior of twenty-three previously synthesized dual DNA gyrase and topoisomerase IV inhibitors was tested in RP-HPLC system, consisting of C8 column and acetonitrile/phosphate buffer (pH 5.5 and pH 7.4) mobile phase. logD was calculated at both pH values and the best correlation with logD was obtained for retention parameter φ0, indicating that this RP-HPLC system could be used as an alternative to the shake-flask determination of lipophilicity. Subsequent QSRR analysis revealed that intrinsic lipophilicity (logP) and molecular weight (bcutm13) have a positive, while solubility (bcutp3) has a negative influence on this retention parameter.

International audience; A practical access to four new halogen-substituted pyrrole building blocks was realized in two to five synthetic steps from commercially available starting materials. The target compounds were prepared on a 50 mg to 1 g scale, and their conversion to nanomolar inhibitors of bacterial DNA gyrase B was demonstrated for three of the prepared building blocks to showcase the usefulness of such chemical motifs in medicinal chemistry.

We designed and synthesized a series of inhibitors of the bacterial enzymes DNA gyrase and DNA topoisomerase IV, based on our recently published benzothiazole-based inhibitor bearing an oxalyl moiety. To improve the antibacterial activity and retain potent enzymatic activity, we systematically explored the chemical space. Several strategies of modification were followed: varying substituents on the pyrrole carboxamide moiety, alteration of the central scaffold, including variation of substitution position and, most importantly, modification of the oxalyl moiety. Compounds with acidic, basic, and neutral properties were synthesized. To understand the mechanism of action and binding mode, we have obtained a crystal structure of compound 16a, bearing a primary amino group, in complex with the N-terminal domain of E. coli gyrase B (24 kDa) (PDB: 6YD9). Compound 15a, with a low molecular weight of 383 Da, potent inhibitory activity on E. coli gyrase (IC50 = 9.5 nM), potent antibacterial activity on E. faecalis (MIC = 3.13 [micro]M), and efflux impaired E. coli strain (MIC = 0.78 [micro]M), is an important contribution for the development of novel gyrase and topoisomerase IV inhibitors in Gram-negative bacteria. Abstract. Bibliografija: str. 2439-2440. EU H2020 ITN-ETN Project INTEGRATE EU FP7 Integrated Project MAREX Academy of Finland ARRS Biotechnology and Biosciences Research Council (UK) Institute Strategic Programme Grant B Wellcome Trust - (Investigator Award)

Microglia are resident macrophages in the central nervous system that are involved in immune responses driven by Toll-like receptors (TLRs). Microglia-mediated inflammation can lead to central nervous system disorders, and more than one TLR might be involved in these pathological processes. The cysteine peptidase cathepsin X has been recognized as a pathogenic factor for inflammation-induced neurodegeneration. Here, we hypothesized that simultaneous TLR3 and TLR4 activation induces synergized microglia responses and that these phenotype changes affect cathepsin X expression and activity. Murine microglia BV2 cells and primary murine microglia were exposed to the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) and the TLR4 ligand lipopolysaccharide (LPS), individually and simultaneously. TLR3 and TLR4 co-activation resulted in increased inflammatory responses compared to individual TLR activation, where poly(I:C) and LPS induced distinct patterns of proinflammatory factors together with different patterns of cathepsin X expression and activity. TLR co-activation decreased intracellular cathepsin X activity and increased cathepsin X localization at the plasma membrane with concomitant increased extracellular cathepsin X protein levels and activity. Inhibition of cathepsin X in BV2 cells by AMS36, cathepsin X inhibitor, significantly reduced the poly(I:C)- and LPS-induced production of proinflammatory cytokines as well as apoptosis. Additionally, inhibiting the TLR3 and TLR4 common signaling pathway, PI3K, with LY294002 reduced the inflammatory responses of the poly(I:C)- and LPS-activated microglia and recovered cathepsin X activity. We here provide evidence that microglial cathepsin X strengthens microglia activation and leads to subsequent inflammation-induced neurodegeneration. As such, cathepsin X represents a therapeutic target for treating neurodegenerative diseases related to excess inflammation.

Heat shock protein 90 (Hsp90) is a chaperone responsible for the maturation of many cancer-related proteins, and is therefore an important target for the design of new anticancer agents. Several Hsp90 N-terminal domain inhibitors have been evaluated in clinical trials, but none have been approved as cancer therapies. This is partly due to induction of the heat shock response, which can be avoided using Hsp90 C-terminal-domain (CTD) inhibition. Several structural features have been shown to be useful in the design of Hsp90 CTD inhibitors, including an aromatic ring, a cationic center and the benzothiazole moiety. This study established a previously unknown link between these structural motifs. Using ligand-based design methodologies and structure-based pharmacophore models, a library of 29 benzothiazole-based Hsp90 CTD inhibitors was prepared, and their antiproliferative activities were evaluated in MCF-7 breast cancer cells. Several showed low-micromolar IC50, with the most potent being compounds 5g and 9i (IC50, 2.8 ± 0.1, 3.9 ± 0.1 μM, respectively). Based on these results, a ligand-based structure–activity relationship model was built, and molecular dynamics simulation was performed to elaborate the binding mode of compound 9i. Moreover, compound 9i showed degradation of Hsp90 client proteins and no induction of the heat shock response.

Human DNA topoisomerase II is an important target in anticancer therapy. Despite the clinical success of drugs that target topoisomerase II, the development of resistant cancer cells can limit their clinical efficacy. To maximize the therapeutic potential of anticancer drugs, combination therapies and multitarget drugs have been suggested in many studies, where the use of multitarget drugs is advantageous from a pharmacokinetic point of view. There are various different options for the preparation of dual-target or multiple-target inhibitors, as topoisomerase II is both structurally (e.g., topoisomerase I, Hsp90, and kinases) and functionally (e.g., histone deacetylases and proteasome) connected to many validated anticancer targets. In this Perspective, we discuss the scientific background behind targeting topoisomerase II together with a number of other targets important in cancer therapy, review the present status, and discuss further options in the field.

Cysteine cathepsins are peptidases with housekeeping functions that play different specific roles in different tissues. Endogenous peptidase inhibitors, such as cystatins and thyropins are the ultimate way of controlling their activity. It appears, however, that cathepsin X, a monocarboxypeptidase, whose overexpression is associated with several patholog- ical processes, is not under the control of endogenous inhibitors. Inhibitors belonging to various groups inhibit other cathepsins tested, but none decrease the carboxypeptidase activity of cathepsin X. This absence of inhibitor control is another feature that distinguishes cathepsin X from other members of the cysteine peptidases. Cisteinski katepsini so peptidaze z vzdrževalno vlogo in z različnimi specifičnimi vlogami v različnih tkivih. Endogeni inhibitorji peptidaz, kot so cistatini in tiropini, so bistveni za nadzor njihove aktivnosti, vendar pa rezultati kažejo, da katepsin X, monokarboksipeptidaza, katere prekomerno izražanje je povezano z več patološkimi procesi, ni pod nad- zorom endogenih inhibitorjev. Inhibitorji, ki pripadajo različnim skupinam, so zavirali druge preizkušene katepsine, nobeden pa ni zmanjšal karboksipeptidazne aktivnosti katepsina X. Odsotnost takega nadzora z inhibitorji, je še ena značilnost, ki razlikuje katepsin X od drugih članov cisteinskih peptidaz.

The rise in multidrug-resistant bacteria defines the need for identification of new antibacterial agents that are less prone to resistance acquisition. Compounds that simultaneously inhibit multiple bacterial targets are more likely to suppress the evolution of target-based resistance than monotargeting compounds. The structurally similar ATP binding sites of DNA gyrase and topoisomerase - offer an opportunity to accomplish this goal. Here we present the design and structure-activity relationship analysis of balanced, low nanomolar inhibitors of bacterial DNA gyrase and topoisomerase IV that show potent antibacterial activities against the ESKAPE pathogens. For inhibitor 31c, a crystal structure in complex with Staphylococcus aureus DNA gyrase B was obtained that confirms the mode of action of these compounds. The best inhibitor, 31h, does not show any in vitro cytotoxicity and has excellent potency against Gram-positive (MICs: range, 0.0078-0.0625 [micro]g/mL) and Gram-negative pathogens (MICs: range, 1-2 [micro]g/mL). Furthermore, 31h inhibits GyrB mutants that can develop resistance to other drugs. Based on these data, we expect that structural derivatives of 31h will represent a step toward clinically efficacious multitargeting antimicrobials that are not impacted by existing antimicrobial resistance. Št. članka: 113200. Bibliografija: str. 21-22. Abstract. ARRS ARRS ARRS

Quorum sensing (QS), a bacterial communication strategy, has been recognized as one of the control mechanisms of virulence in bacteria. Thus, targeting QS offers an interesting opportunity to impair bacterial pathogenicity and develop antivirulence agents. Aiming to enhance the discovery of QS inhibitors, we developed a bioreporter E. coli JW5505 pET-Plsrlux and set up a cell-based assay for identifying inhibitors of autoinducer-2 (AI-2) -mediated QS. A comparative study on the performance of target-based and cell-based assay was performed. 91 compounds selected with the potential to target the ATP binding pocket of LsrK, a key enzyme in AI-2 processing, were tested in a LsrK inhibition assay providing 36 hits. The same set of compounds was tested by the AI-2-mediated QS interference assay resulting in 24 active compounds. Among those, 6 compounds were also active against LsrK whereas 18 may target other components of the pathway. Thus, the AI-2-mediated QS interference cell-based assay is an effective tool for complementing target-based assays but also as independent assay for primary screening. Nasl. z nasl. zaslona. Opis vira z dne 7. 2. 2020. Abstract. ARRS European Union’s Horizon 2020 research and innovation program under the Marie SkłodowskaCurie, INTEGRATE Academy of Finland Academy of Finland

Benzo[d]thiazole is widely used in synthetic and medicinal chemistry, and it is a component of many compounds and drugs that have several different bioactivities. Herein, we describe an elegant pathway for synthesis of methyl 4- and 5-hydroxy-2-amino-benzo[d]thiazole-6-carboxylates as building blocks that can be substituted at four different positions on the bicycle and thus offer the possibility to thoroughly explore the chemical space around the molecule studied as a ligand for the chosen target. A series of 12 new compounds was prepared using the described methods and Williamson ether synthesis. Nasl. z nasl. zaslona. Opis vira z dne 3. 4. 2020. Bibliografija: str. 8310-8311. Abstract. ARRS

Aim: DNA gyrase and topoisomerase IV are essential bacterial enzymes, and in the fight against bacterial resistance, they are important targets for the development of novel antibacterial drugs. Results: Building from our first generation of 4,5,6,7-tetrahydrobenzo[ d]thiazole-based DNA gyrase inhibitors, we designed and prepared an optimized series of analogs that show improved inhibition of DNA gyrase and topoisomerase IV from Staphylococcus aureus and Escherichia coli, with IC50 values in the nanomolar range. Importantly, these inhibitors also show improved antibacterial activity against Gram-positive strains. Conclusion: The most promising inhibitor, 29, is active against Enterococcus faecalis, Enterococcus faecium and S. aureus wild-type and resistant strains, with minimum inhibitory concentrations between 4 and 8 μg/ml, which represents good starting point for development of novel antibacterials.

Multidrug resistance (MDR) is the dominant cause of the failure of cancer chemotherapy. The design of antitumor drugs that are able to evade MDR is rapidly evolving, showing that this area of biomedical research attracts great interest in the scientific community. The current review explores promising recent approaches that have been developed with the aim of circumventing or overcoming MDR. Encouraging results have been obtained in the investigation of the MDR-modulating properties of various classes of natural compounds and their analogues. Inhibition of P-gp or downregulation of its expression have proven to be the main mechanisms by which MDR can be surmounted. The use of hybrid molecules that are able to simultaneously interact with two or more cancer cell targets is currently being explored as a means to circumvent drug resistance. This strategy is based on the design of hybrid compounds that are obtained either by merging the structural features of separate drugs, or by conjugating two drugs or pharmacophores via cleavable/non-cleavable linkers. The approach is highly promising due to the pharmacokinetic and pharmacodynamic advantages that can be achieved over the independent administration of the two individual components. However, it should be stressed that the task of obtaining successful multivalent drugs is a very challenging one. The conjugation of anticancer agents with nitric oxide (NO) donors has recently been developed, creating a particular class of hybrid that can combat tumor drug resistance. Appropriate NO donors have been shown to reverse drug resistance via nitration of ABC transporters and by interfering with a number of metabolic enzymes and signaling pathways. In fact, hybrid compounds that are produced by covalently attaching NO-donors and antitumor drugs have been shown to elicit a synergistic cytotoxic effect in a variety of drug resistant cancer cell lines. Another strategy to circumvent MDR is based on nanocarrier-mediated transport and the controlled release of chemotherapeutic drugs and P-gp inhibitors. Their pharmacokinetics are governed by the nanoparticle or polymer carrier and make use of the enhanced permeation and retention (EPR) effect, which can increase selective delivery to cancer cells. These systems are usually internalized by cancer cells via endocytosis and accumulate in endosomes and lysosomes, thus preventing rapid efflux. Other modalities to combat MDR are described in this review, including the pharmaco-modulation of acridine, which is a well-known scaffold in the development of bioactive compounds, the use of natural compounds as means to reverse MDR, and the conjugation of anticancer drugs with carriers that target specific tumor-cell components. Finally, the outstanding potential of in silico structure-based methods as a means to evaluate the ability of antitumor drugs to interact with drug transporters is also highlighted in this review. Structure-based design methods, which utilize 3D structural data of proteins and their complexes with ligands, are the most effective of the in silico methods available, as they provide a prediction regarding the interaction between transport proteins and their substrates and inhibitors. The recently resolved X-ray structure of human P-gp can help predict the interaction sites of designed compounds, providing insight into their binding mode and directing possible rational modifications to prevent them from becoming P-gp drug substrates. In summary, although major efforts were invested in the search for new tools to combat drug resistant tumors, they all require further implementation and methodological development. Further investigation and progress in the abovementioned strategies will provide significant advances in the rational combat against cancer MDR.

Antibiotics that inhibit multiple bacterial targets offer a promising therapeutic strategy against resistance evolution, but developing such antibiotics is challenging. Here we demonstrate that a rational design of balanced multitargeting antibiotics is feasible by using a medicinal chemistry workflow. The resultant lead compounds, ULD1 and ULD2, belonging to a novel chemical class, almost equipotently inhibit bacterial DNA gyrase and topoisomerase IV complexes and interact with multiple evolutionary conserved amino acids in the ATP-binding pockets of their target proteins. ULD1 and ULD2 are excellently potent against a broad range of gram-positive bacteria. Notably, the efficacy of these compounds was tested against a broad panel of multidrug-resistant Staphylococcus aureus clinical strains. Antibiotics with clinical relevance against staphylococcal infections fail to inhibit a significant fraction of these isolates, whereas both ULD1 and ULD2 inhibit all of them (minimum inhibitory concentration [MIC] ≤1 μg/mL). Resistance mutations against these compounds are rare, have limited impact on compound susceptibility, and substantially reduce bacterial growth. Based on their efficacy and lack of toxicity demonstrated in murine infection models, these compounds could translate into new therapies against multidrug-resistant bacterial infections., This study designs novel antimicrobial compounds that inhibit multiple bacterial targets, making the spontaneous evolution of resistance extremely rare. These compounds inhibited the growth of all multidrug resistant Staphylococcus aureus (MRSA) isolates tested, while existing antibiotics remained largely ineffective.

A series of 3-methyl-2-phenyl-1H-indoles was prepared and investigated for antiproliferative activity on three human tumor cell lines, HeLa, A2780, and MSTO-211H, and some structure-activity relationships were drawn up. The GI50 values of the most potent compounds (32 and 33) were lower than 5 [micro]M in all tested cell lines. For the most biologically relevant derivatives, the effect on human DNA topoisomerase II relaxation activity was investigated, which highlighted the good correlation between the antiproliferative effect and topoisomerase II inhibition. The most potent derivative, 32, was shown to induce the apoptosis pathway. The obtained results highlight 3-methyl-2-phenyl-1H-indole as a promising scaffold for further optimization of compounds with potent antiproliferative and antitopoisomerase II activities. Abstract. Bibliografija: str. 697. ARRS Ministero dell’Istruzione, dell’Università e della Ricerca

Bacterial DNA gyrase is an important target for the development of novel antibacterial drugs, which are urgently needed because of high level of antibiotic resistance worldwide. We designed and synthesized new 4,5,6,7-tetrahydrobenzo[d]thiazole-based DNA gyrase B inhibitors and their conjugates with siderophore mimics, which were introduced to increase the uptake of inhibitors into the bacterial cytoplasm. The most potent conjugate 34 had an IC50 of 58 nM against Escherichia coli DNA gyrase and displayed MIC of 14 [micro]g/mL against E. coli [micro]tolC strain. Only minor improvements in the antibacterial activities against wild-type E. coli in low-iron conditions were seen for DNA gyrase inhibitor - siderophore mimic conjugates. Članek s št.: 103550. Abstract. Bibliografija: str. 12-13. ARRS Academy of Finland Academy of Finland Academy of Finland

We have prepared three alkaloids from the Agelas sponges, clathrodin, hymenidin and oroidin, and a series of their synthetic analogues, and evaluated their inhibitory effect against six isoforms of the K v 1 subfamily of voltage-gated potassium channels, K v 1.1-K v 1.6, expressed in Chinese Hamster ovary (CHO) cells using automated patch clamp electrophysiology assay. The most potent inhibitor was the ( E )- N -(3-(2-amino-1 H -imidazol-4-yl)allyl)-4,5-dichloro-1 H -pyrrole-2-carboxamide ( 6g ) with IC 50 values between 1.4 and 6.1 μM against K v 1.3, K v 1.4, K v 1.5 and K v 1.6 channels. All compounds tested displayed selectivity against K v 1.1 and K v 1.2 channels. For confirmation of their activity and selectivity, compounds were additionally evaluated in the second independent system against K v 1.1-K v 1.6 and K v 10.1 channels expressed in Xenopus laevis oocytes under voltage clamp conditions where IC 50 values against K v 1.3-K v 1.6 channels for the most active analogues (e.g. 6g ) were lower than 1 μM. Because of the observed low sub-micromolar IC 50 values and fairly low molecular weights, the prepared compounds represent good starting points for further optimisation towards more potent and selective voltage-gated potassium channel inhibitors.

The emergence of multidrug-resistant bacteria is a global health threat necessitating the discovery of new antibacterials and novel strategies for fighting bacterial infections. We report first-in-class DNA gyrase B (GyrB) inhibitor/ciprofloxacin hybrids that display antibacterial activity against Escherichia coli. Whereas DNA gyrase ATPase inhibition experiments, DNA gyrase supercoiling assays, and in vitro antibacterial assays suggest binding of the hybrids to the E. coli GyrA and GyrB subunits, an interaction with the GyrA fluoroquinolone-binding site seems to be solely responsible for their antibacterial activity. Our results provide a foundation for a new concept of facilitating entry of nonpermeating GyrB inhibitors into bacteria by conjugation with ciprofloxacin, a highly permeable GyrA inhibitor. A hybrid molecule containing GyrA and GyrB inhibitor parts entering the bacterial cell would then elicit a strong antibacterial effect by inhibition of both the GyrA and GyrB subunits of DNA gyrase and potentially slow bacterial resistance development.

The identification of the V600E activating mutation in the protein kinase BRAF in around 50% of melanoma patients has driven the development of highly potent small inhibitors (BRAFi) of the mutated protein. To date, Dabrafenib and Vemurafenib, two specific BRAFi, have been clinically approved for the treatment of metastatic melanoma. Unfortunately, after the initial response, tumors become resistant and patients develop a progressive and lethal disease, making imperative the development of new therapeutic options. The main objective of this work was to find new BRAF inhibitors with different structural scaffolds than those of the known inhibitors. Our study was carried out in different stages; in the first step we performed a virtual screening that allowed us to identify potential new inhibitors. In the second step, we synthesized and tested the inhibitory activity of the novel compounds founded. Finally, we conducted a molecular modelling study that allowed us to understand interactions at the molecular level that stabilize the formation of the different molecular complexes. Our theoretical and experimental study allowed the identification of four new structural scaffolds, which could be used as starting structures for the design and development of new inhibitors of BRAF. Our experimental data indicate that the most active compounds reduced significantly ERK½ phosphorylation, a measure of BRAF inhibition, and cell viability. Thus, from our theoretical and experimental results, we propose new substituted hydroxynaphthalenecarboxamides, N-(hetero)aryl-piperazinylhydroxyalkylphenylcarbamates, substituted piperazinylethanols and substituted piperazinylpropandiols as initial structures for the development of new inhibitors for BRAF. Moreover, by performing QTAIM analysis, we are able to describe in detail the molecular interactions that stabilize the different Ligand-Receptor complexes. Such analysis indicates which portion of the different molecules must be changed in order to obtain an increase in the binding affinity of these new ligands. Fil: Campos, Ludmila Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina Fil: Garibotto, Francisco Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina Fil: Angelina, Emilio Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina Fil: Kos, Jiri. Univerzita Palackého v Olomouci; República Checa Fil: Tomašič, Tihomir. Univerza v Ljubljani; Eslovenia Fil: Zidar, Nace. Univerza v Ljubljani; Eslovenia Fil: Kikelj, Danijel. Univerza v Ljubljani; Eslovenia Fil: Gonec, Tomas. Veterinární a farmaceutická univerzita Brno; República Checa Fil: Marvanova, Pavlina. Veterinární a farmaceutická univerzita Brno; República Checa Fil: Mokry, Petr. Veterinární a farmaceutická univerzita Brno; República Checa Fil: Jampilek, Josef. Univerzita Palackého v Olomouci; República Checa. Univerzita Komenského v Bratislave; Eslovaquia Fil: Alvarez, Sergio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina Fil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina

Due to the rapid development of antimicrobial resistance, the discovery of new antibacterials is essential in the fight against potentially lethal infections. The DNA gyrase B (GyrB) subunit of bacterial DNA gyrase is an excellent target for the design of antibacterials, as it has been clinically validated by novobiocin. However, there are currently no drugs in clinical use that target GyrB. We prepared a new series of N-phenyl-4,5-dibromopyrrolamides and evaluated them against DNA gyrase and against the structurally and functionally similar enzyme, topoisomerase IV. The most active compound, 28, had an IC50 of 20 nM against Escherichia coli DNA gyrase. The IC50 values of 28 against Staphylococcus aureus DNA gyrase, and E. coli and S. aureus topoisomerase IV were in the low micromolar range. However, the compounds evaluated did not show significant antibacterial activities against selected Gram-positive and Gram-negative bacteria. Our results indicate that for potent inhibition of DNA gyrase, a combination of polar groups on the carboxylic end of the molecule and substituents that reach into the ''lipophilic floor'' of the enzyme is required. Članek objavljen 20. maja 2019. Abstract. Bibliografija: str. 1016-1017. ARRS Academy of Finland Academy of Finland Academy of Finland

The bacterial topoisomerases DNA gyrase and topoisomerase IV are validated targets for development of novel antibacterial agents. Fluoroquinolones inhibit the catalytic GyrA and/or ParC(GrlA) subunit and have been commonly used, although these have toxicity liabilities that restrict their use. The ATPase GyrB and ParE(GrlB) subunits have been much less explored and after withdrawal of novobiocin, there are no further marketed inhibitors . ATP-competitive inhibitors of GyrB and/or ParE(GrlB) are of special interest, as this target has been validated, and it is expected that many of the problems associated with fluoroquinolones can be avoided.This review summarises the development of ATP-competitive inhibitors of GyrB and/or ParE(GrlB) as novel antibacterial agents over the last 10 years. Structural features of the new inhibitors and their optimisation strategies are highlighted.The development of novel ATP-competitive inhibitors of GyrB and/or ParE(GrlB) is ongoing in industrial and academical research. Development of resistance is one of the most problematic issues, but GyrB/ParE(GrlB) inhibitors do not show cross-resistance with fluoroquinolones. Other common issues, such as low solubility, high protein binding, development of off-target resistance, are related to the structures of the inhibitors themselves, which is thus a main focus of design strategies. With some now in early clinical development, there is reasonable expectation that novel ATP-competitive inhibitors of GyrB/ParE(GrlB) will reach the market in the near future.

Parkinson’s disease (PD) is a progressive neurodegenerative disorder with unknown cause, but it has been postulated that chronic neuroinflammation may play a role in its pathogenesis. Microglia-derived lysosomal cathepsins have been increasingly recognized as important inflammatory mediators. Here, we analyzed the regional distribution and cellular localization of the cathepsin X in the rat brain with neuroinflammation-induced neurodegeneration. Unilateral injection of lipopolysaccharide (LPS) into the striatum induced strong upregulation of cathepsin X expression and its activity in the ipsilateral striatum. In addition to the striatum, cathepsin X overexpression was detected in other areas such as cerebral cortex, corpus callosum, subventricular zone and external globus pallidus mainly restricted to glial cells. Moreover, continuous administration of the cathepsin X specific inhibitor AMS36 showed protective effects against LPS-induced striatal degeneration, as seen by the decreased extent of striatal lesion and decreased expression of neuroinflammation marker. These results demonstrate that glial upregulated cathepsin X may play a role as a potential pathogenic factor in PD. Inhibition of cathepsin X enzymatic activity thus may be useful in preventing neuroinflammation-induced neurodegeneration.

5 p.-4 fig.-1 tab.-2 schem + 10 p. inf. supl., Four different hybrid compounds have been efficiently synthesized by conjugation of deacetylthiocolchicine with pironetin‐inspired derivatives. The modest bioactivity and the apparent absence of interaction with α‐tubulin is explained by a posteriori in silico investigation, which suggests a relevant distance between the thiocolchicine binding site and the proper pocket on the α‐tubulin. The modest activity on resistant cells suggested that the lipophilic nature of the linker used renders the resulting compounds better substrates for p‐Gp efflux pumps. The study better clarifies the design of bivalent compounds that target hetero tubulin/microtubules., D.P. expresses his gratitude to MAECI Italia‐India Strategic Projects 2017‐2019 MAE0105301 “Development of nature inspired bivalent antitubulins as anticancer agents”. This work has been developed under the umbrella of COST Action CM1407, “Challenging organic syntheses inspired by nature ‐ from natural products chemistry to drug discovery” that favoured the networking and financed an STSM grant for N.Z.

ATP competitive inhibitors of DNA gyrase and topoisomerase IV have great therapeutic potential, but none of the described synthetic compounds has so far reached the market. To optimise the activities and physicochemical properties of our previously reported N-phenylpyrrolamide inhibitors, we have synthesized an improved, chemically variegated selection of compounds and evaluated them against DNA gyrase and topoisomerase IV enzymes, and against selected Gram-positive and Gram-negative bacteria. The most potent compound displayed IC50 values of 6.9%nM against Escherichia coli DNA gyrase and 960%nM against Staphylococcus aureus topoisomerase IV. Several compounds displayed minimum inhibitory concentrations (MICs) against Gram-positive strains in the 1-50%%M range, one of which inhibited the growth of Enterococcus faecalis, Enterococcus faecium, S. aureus and Streptococcus pyogenes with MIC values of 1.56%%M, 1.56%%M, 0.78%%M and 0.72%%M, respectively. This compound has been investigated further on methicillin-resistant S. aureus (MRSA) and on ciprofloxacin non-susceptible and extremely drug resistant strain of S. aureus (MRSA VISA). It exhibited the MIC value of 2.5%%M on both strains, and MIC value of 32%%M against MRSA in the presence of inactivated human blood serum. Further studies are needed to confirm its mode of action. Bibliografija: str. 289-290. Abstract. ARRS Academy of Finland Academy of Finland Academy of Finland European Research Council, Resistance Evolution GINOP GINOP PhD fellowship from the Boehringer Ingelheim Fonds

Human DNA topoisomerase II is one of the major targets in anticancer therapy, however ATP-competitive inhibitors of this target have not yet reached their full potential. ATPase domain of human DNA topoisomerase II belongs to the GHKL ATPase superfamily and shares a very high 3D structural similarity with other superfamily members, including bacterial topoisomerases. In this work we report the discovery of a new chemotype of ATP-competitive inhibitors of human DNA topoisomerase IIα that were discovered through screening of in-house library of ATP-competitive inhibitors of bacterial DNA gyrase and topoisomerase IV. Systematic screening of this library provided us with 20 hit compounds. 1,2,4-Substituted N-phenylpyrrolamides were selected for a further exploration which resulted in 13 new analogues, including 52 with potent activity in relaxation assay (IC50 = 3.2 µM) and ATPase assay (IC50 = 0.43 µM). Cytotoxic activity of all hits was determined in MCF-7 cancer cell line and the most potent compounds, 16 and 20, showed an IC50 value of 8.7 and 8.2 µM, respectively.

Cathepsin X is a cysteine carboxypeptidase that is involved in various physiological and pathological processes. In particular, highly elevated expression and activity of cathepsin X has been observed in cancers and neurodegenerative diseases. Previously, we identified compound Z9 (1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-((4-isopropyl-4H-1,2,4-triazol-3-yl)thio)ethan-1-one) as a potent and specific reversible cathepsin X inhibitor. Here, we have explored the effects of chemical variations to Z9 of either benzodioxine or triazol moieties, and the importance of the central ketomethylenethio linker. The ketomethylenethio linker was crucial for cathepsin X inhibition, whereas changes of the triazole heterocycle did not alter the inhibitory potencies to a greater extent. Replacement of benzodioxine moiety with substituted benzenes reduced cathepsin X inhibition. Overall, several synthesized compounds showed similar or improved inhibitory potencies against cathepsin X compared to Z9, with IC50 values of 7.1 μM–13.6 μM. Additionally, 25 inhibited prostate cancer cell migration by 21%, which is under the control of cathepsin X.

The ATP binding site located on the subunit B of DNA gyrase is an attractive target for the development of new antibacterial agents. In recent decades, several small-molecule inhibitor classes have been discovered but none has so far reached the market. We present here the discovery of a promising new series of N-phenylpyrrolamides with low nanomolar IC50 values against DNA gyrase, and submicromolar IC50 values against topoisomerase IV from Escherichia coli and Staphylococcus aureus. The most potent compound in the series has an IC50 value of 13nM against E. coli gyrase. Minimum inhibitory concentrations (MICs) against Gram-positive bacteria are in the low micromolar range. The oxadiazolone derivative 11a, with an IC50 value of 85nM against E. coli DNA gyrase displays the most potent antibacterial activity, with MIC values of 1.56 microM against Enterococcus faecalis, and 3.13 microM against wild type S. aureus, methicillin-resistant S. aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The activity against wild type E. coli in the presence of efflux pump inhibitor phenylalanine-arginine beta-naphthylamide (PA(beta)N) is 4.6microM. Objavljeno 10 maja 2018. Bibliografija: str. 131-132. Abstract. ARRS Academy of Finland Academy of Finland Academy of Finland European Research Council, Resistance Evolution Wellcome Trust (to C.P.), and GINOP (MolMedEx TUMORDNS) GINOP (EVOMER) Lendület’ Program of the Hungarian Academy of Science, PhD fellowship from the Boehringer Ingelheim Fonds

Bacterial cell walls and membranes provide essential protection for bacteria against environmental influences. Different bacteria possess different cell envelopes and understanding each of these structures is crucial for the design of effective antibacterial drugs whose targets are intracellular. Optimal properties of drugs that are required for their entry into bacteria are still hard to predict. The guidelines that are suitable and well established for the penetration of a drug into eukaryotic cells are poorly adaptable to the complex world of pathogens. Areas covered: The factors that govern the penetration of anti-infection drugs into bacteria are examined and the available strategies to overcome this therapeutically very important barrier are reviewed. The areas covered include optimization of the physicochemical properties of compounds, utilization of iron-chelating compounds, i.e. siderophores, the use of efflux pump inhibitors, and of carriers such as liposomes. Expert opinion: Although several rules governing permeation have recently been proposed for effective antibacterial drugs, none of them has been so far established as the 'golden' rule. Thus, new research is needed to find a more general approach on how to increase the concentration of antibacterial compounds in bacterial cells.

Bacterial DNA gyrase is a well-known and validated target in the design of antibacterial drugs. However, inhibitors of its ATP binding subunit, DNA gyrase B (GyrB), have so far not reached clinical use. In the present study, three different series of N-phenyl-4,5-dibromopyrrolamides and N-phenylindolamides were designed and prepared as potential DNA gyrase B inhibitors. The IC50 values of compounds on DNA gyrase from Escherichia coli were in the low micromolar range, with the best compound, (4-(4,5-dibromo-1H-pyrrole-2-carboxamido)benzoyl)glycine (18a), displaying an IC50 of 450 nM. For this compound, a high-resolution crystal structure in complex with E. coli DNA gyrase B was obtained, revealing details of its binding mode within the active site. The binding affinities of three compounds with GyrB were additionally evaluated by surface plasmon resonance, and the results were in good agreement with the determined enzymatic activities. For the most promising compounds, the inhibitory activities against DNA gyrase from Staphylococcus aureus and topoisomerases IV from E. coli and S. aureus were determined. Antibacterial activities of the most potent compounds of each series were evaluated against two Gram-positive and two Gram-negative bacterial strains. The results obtained in this study provide valuable information on the binding mode and structure-activity relationship of N-phenyl-4,5-dibromopyrrolamides and N-phenylindolamides as promising classes of ATP competitive GyrB inhibitors.

ATP-competitive inhibitors of DNA gyrase and topoisomerase IV are among the most interesting classes of antibacterial drugs that are unrepresented in the antibacterial pipeline. We developed 32 new N-phenylpyrrolamides and evaluated them against DNA gyrase and topoisomerase IV from E. coli and Staphylococcus aureus. Antibacterial activities were studied against Gram-positive and Gram-negative bacterial strains. The most potent compound displayed an IC50 of 47micro nm against E.coli DNA gyrase, and a minimum inhibitory concentration (MIC) of 12.5 microm against the Gram-positive Enterococcus faecalis. Some compounds displayed good antibacterial activities against an efflux-pump-deficient E. coli strain (MIC=6.25 microm) and against wild-type E. coli in the presence of efflux pump inhibitor PAbetaN (MIC=3.13 microm). Here we describe new findings regarding the structure-activity relationships of N-phenylpyrrolamide DNA gyrase B inhibitors and investigate the factors that are important for the antibacterial activity of this class of compounds. Nasl. z nasl. zaslona. Opis vira z dne 19. 1. 2018. Bibliografija: str. 198. Abstract. ARRS EU FP7 Integrated Project MAREX EU H2020 ITN-ETN Project Academy of Finland Academy of Finland

Development of novel DNA gyrase B inhibitors is an important field of antibacterial drug discovery whose aim is to introduce a more effective representative of this mechanistic class into the clinic. In the present study, two new series of Escherichia coli DNA gyrase inhibitors bearing the 4,5-dibromopyrrolamide moiety have been designed and synthesized. 4,5,6,7-Tetrahydrobenzo[1,2-d] thiazole-2,6-diamine derivatives inhibited E. coli DNA gyrase in the submicromolar to low micromolar range (IC50 values between 0.891 and 10.4 mu M). Their "ring-opened" analogues, based on the 2-(2-aminothiazol-4-yl) acetic acid scaffold, displayed weaker DNA gyrase inhibition with IC50 values between 15.9 and 169 mu M. Molecular docking experiments were conducted to study the binding modes of inhibitors. (C) 2016 Elsevier Ltd. All rights reserved.

The cysteine carboxypeptidase cathepsin X is an important player in degenerative processes under normal ageing and pathological conditions. In the present study, we investigated the potential role of cathepsin X in 6-hydroxydopamine (6-OHDA)-induced toxicity in the pheochromocytoma cell line PC12 and neuroblastoma cell line SH-SY5Y. Cells exposed to 6-OHDA demonstrated alterations in the protein level of cathepsin X and activity of cathepsin X. Downregulation of cathepsin X expression by siRNA attenuated the neuronal death caused by 6-OHDA. Treatment with specific cathepsin X inhibitor AMS36 protected cells against 6-OHDA mediated cytotoxicity, resulting in reduced cell death and apoptosis. Furthermore, AMS36 reversed 6-OHDA-induced loss of tyrosine hydroxylase and attenuated 6-OHDA-induced activation of caspase-3, triggering apoptosis, intracellular generation of reactive oxygen species and mitochondrial dysfunction, including the release of cytochrome c and an imbalanced Bax/Bcl-2 ratio. Moreover, AMS36 interfered with NF-κB activation by blocking degradation of IκBα, preventing NF-κB translocation to the nucleus. Our data provide the first evidence that inhibition of cathepsin X protects both, PC12 and SH-SY5Y cells against 6-OHDA toxicity and indicate that cathepsin X may be responsible for dopamine neuron death, involved in the pathogenic cascade event for the neurodegenerative disorders, such as Parkinson's disease.