scholarly journals Mechanism-Based Covalent Neuraminidase Inhibitors with Broad-Spectrum Influenza Antiviral Activity

Science ◽  
2013 ◽  
Vol 340 (6128) ◽  
pp. 71-75 ◽  
Author(s):  
Jin-Hyo Kim ◽  
Ricardo Resende ◽  
Tom Wennekes ◽  
Hong-Ming Chen ◽  
Nicole Bance ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antiviral Agents ◽  
Neuraminidase Inhibitor ◽  
New Class ◽  
Development Of Resistance ◽  
Spectrum Activity ◽  
Future Utility ◽  
Drug Resistant Strains ◽  
Covalent Intermediate

Influenza antiviral agents play important roles in modulating disease severity and in controlling pandemics while vaccines are prepared, but the development of resistance to agents like the commonly used neuraminidase inhibitor oseltamivir may limit their future utility. We report here on a new class of specific, mechanism-based anti-influenza drugs that function through the formation of a stabilized covalent intermediate in the influenza neuraminidase enzyme, and we confirm this mode of action with structural and mechanistic studies. These compounds function in cell-based assays and in animal models, with efficacies comparable to that of the neuraminidase inhibitor zanamivir and with broad-spectrum activity against drug-resistant strains in vitro. The similarity of their structure to that of the natural substrate and their mechanism-based design make these attractive antiviral candidates.

scholarly journals Non-Toxic Virucidal Macromolecules Show High Efficacy Against Influenza Virus Ex Vivo and In Vivo

2020 ◽  
Author(s):  
Ozgun Kocabiyik ◽  
Valeria Cagno ◽  
Paulo Jacob Silva ◽  
Yong Zhu ◽  
Laura Sedano ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Viral Infections ◽  
Ex Vivo ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
New Class ◽  
Influenza Strain ◽  
Low Toxicity

AbstractInfluenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6’sialyl-N-acetyllactosamine (6’SLN) or 3’SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..

scholarly journals Rational design, synthesis and testing of novel tricyclic topoisomerase inhibitors for the treatment of bacterial infections part 2

2020 ◽  
Vol 11 (12) ◽  
pp. 1379-1385
Author(s):  
R. Kirk ◽  
A. Ratcliffe ◽  
G. Noonan ◽  
M. Uosis-Martin ◽  
D. Lyth ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Bacterial Infections ◽  
Rational Design ◽  
Topoisomerase Ii ◽  
Topoisomerase Inhibitors ◽  
Design Synthesis ◽  
Pharmacokinetic Properties ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

We disclose the discovery of REDX07965, a novel tricyclic topoisomerase inhibitor (NTTI) which has broad spectrum activity, favourable in vitro pharmacokinetic properties and selectivity versus human topoisomerase II.

scholarly journals GC-072, a Novel Therapeutic Candidate for Oral Treatment of Melioidosis and Infections Caused by Select Biothreat Pathogens

2019 ◽  
Vol 63 (12) ◽  
Author(s):  
Jeffry D. Shearer ◽  
Michelle L. Saylor ◽  
Christine M. Butler ◽  
Anthony M. Treston ◽  
Henry S. Heine ◽  
...  
Keyword(s):  
Acute Phase ◽  
Oral Treatment ◽  
Lethal Dose ◽  
Current Therapy ◽  
Content Type ◽  
Development Of Resistance ◽  
Strong Candidate ◽  
Oral Therapeutic ◽  
Drug Resistant Strains

ABSTRACT Burkholderia pseudomallei, the etiological agent of melioidosis, is a Gram-negative bacterium with additional concern as a biothreat pathogen. The mortality rate from B. pseudomallei varies depending on the type of infection and extent of available health care; in the case of septicemia, left untreated, it can range from 50% to 90%. Current therapy for melioidosis is biphasic, consisting of parenteral acute-phase treatment for 2 weeks or longer, followed by oral eradication-phase treatment lasting several months. An effective oral therapeutic for outpatient treatment of acute-phase melioidosis is needed. GC-072 is a potent, 4-oxoquinolizine antibiotic with selective inhibitory activity against bacterial topoisomerases. GC-072 has demonstrated in vitro potency against susceptible and drug-resistant strains of B. pseudomallei and is also active against Burkholderia mallei, Bacillus anthracis, Yersinia pestis, and Francisella tularensis. GC-072 is bactericidal both extra- and intracellularly, with rapid killing noted within a few hours and reduced development of resistance compared to that for ceftazidime. GC-072, delivered intragastrically to mimic oral administration, promoted dose-dependent survival in mice using lethal inhalational models of B. pseudomallei infection following exposure to a 24- or 339-LD50 (50% lethal dose) challenge with B. pseudomallei strain 1026b. Overall, GC-072 appears to be a strong candidate for first-line oral treatment of melioidosis.

scholarly journals Molluscum Contagiosum Virus Topoisomerase: Purification, Activities, and Response to Inhibitors

1998 ◽  
Vol 72 (4) ◽  
pp. 3401-3406 ◽  
Author(s):  
Young Hwang ◽  
Beibei Wang ◽  
Frederic D. Bushman
Keyword(s):  
Antiviral Agents ◽  
Covalent Bond ◽  
Molluscum Contagiosum ◽  
Type I ◽  
Molluscum Contagiosum Virus ◽  
Type I Topoisomerases ◽  
Covalent Intermediate ◽  
Point Of Departure ◽  
Probable Type

ABSTRACT Molluscum contagiosum virus (MCV), the only member of theMolluscipoxvirus genus, causes benign papules in healthy people but disfiguring lesions in immunocompromised patients. The sequence of MCV has been completed, revealing that MCV encodes a probable type I topoisomerase enzyme. All poxviruses sequenced to date also encode type I topoisomerases, and in the case of vaccinia virus the topoisomerase has been shown to be essential for replication. Thus, inhibitors of the MCV topoisomerase might be useful as antiviral agents. We have cloned the gene for MCV topoisomerase, overexpressed and purified the protein, and begun to characterize its activities in vitro. Like other eukaryotic type I topoisomerases, MCV topoisomerase can relax both positive and negative supercoils. An analysis of the cleavage of plasmid and oligonucleotide substrates indicates that cleavage by MCV topoisomerase is favored just 3′ of the sequence 5′ (T/C)CCTT 3′, resulting in formation of a covalent bond to the 3′ T residue, as with other poxvirus topoisomerases. We identified solution conditions favorable for activity and measured the rate of formation and decay of the covalent intermediate. MCV topoisomerase is sensitive to inhibition by coumermycin A1 (50% inhibitory concentration, 32 μM) but insensitive to five other previously reported topoisomerase inhibitors. This work provides the point of departure for studies of the mechanism of function of MCV topoisomerase and the development of medically useful inhibitors.

scholarly journals Discovery of a cofactor-independent inhibitor ofMycobacterium tuberculosisInhA

2018 ◽  
Vol 1 (3) ◽  
pp. e201800025 ◽  
Author(s):  
Yi Xia ◽  
Yasheen Zhou ◽  
David S Carter ◽  
Matthew B McNeil ◽  
Wai Choi ◽  
...  
Keyword(s):  
Oral Delivery ◽  
Drug Exposure ◽  
Drug Resistant ◽  
Antitubercular Agents ◽  
Independent Manner ◽  
Structural Investigations ◽  
New Class ◽  
Enoyl Acp Reductase ◽  
Drug Resistant Strains

New antitubercular agents are needed to combat the spread of multidrug- and extensively drug-resistant strains ofMycobacterium tuberculosis. The frontline antitubercular drug isoniazid (INH) targets the mycobacterial enoyl-ACP reductase, InhA. Resistance to INH is predominantly through mutations affecting the prodrug-activating enzyme KatG. Here, we report the identification of the diazaborines as a new class of direct InhA inhibitors. The lead compound, AN12855, exhibited in vitro bactericidal activity against replicating bacteria and was active against several drug-resistant clinical isolates. Biophysical and structural investigations revealed that AN12855 binds to and inhibits the substrate-binding site of InhA in a cofactor-independent manner. AN12855 showed good drug exposure after i.v. and oral delivery, with 53% oral bioavailability. Delivered orally, AN12855 exhibited dose-dependent efficacy in both an acute and chronic murine model of tuberculosis infection that was comparable with INH. Combined, AN12855 is a promising candidate for the development of new antitubercular agents.

scholarly journals Defective viral genomes from chikungunya virus are broad-spectrum antivirals and prevent virus dissemination in mosquitoes

2021 ◽  
Vol 17 (2) ◽  
pp. e1009110
Author(s):  
Laura I. Levi ◽  
Veronica V. Rezelj ◽  
Annabelle Henrion-Lacritick ◽  
Diana Erazo ◽  
J Boussier ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Broad Spectrum ◽  
Chikungunya Virus ◽  
Rna Virus ◽  
Viral Genomes ◽  
Mosquito Cells ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

Defective viral genomes (DVGs) are truncated and/or rearranged viral genomes produced during virus replication. Described in many RNA virus families, some of them have interfering activity on their parental virus and/or strong immunostimulatory potential, and are being considered in antiviral approaches. Chikungunya virus (CHIKV) is an alphavirus transmitted by Aedes spp. that infected millions of humans in the last 15 years. Here, we describe the DVGs arising during CHIKV infection in vitro in mammalian and mosquito cells, and in vivo in experimentally infected Aedes aegypti mosquitoes. We combined experimental and computational approaches to select DVG candidates most likely to have inhibitory activity and showed that, indeed, they strongly interfere with CHIKV replication both in mammalian and mosquito cells. We further demonstrated that some DVGs present broad-spectrum activity, inhibiting several CHIKV strains and other alphaviruses. Finally, we showed that pre-treating Aedes aegypti with DVGs prevented viral dissemination in vivo.

scholarly journals Broad-spectrum virucidal activity of bacterial secreted lipases against flaviviruses, SARS-CoV-2 and other enveloped viruses

2020 ◽  
Author(s):  
Xi Yu ◽  
Liming Zhang ◽  
Liangqin Tong ◽  
Nana Zhang ◽  
Han Wang ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Lipase Activity ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Viral Envelope ◽  
Global Public Health ◽  
Virucidal Activity ◽  
Extracellular Milieu

AbstractViruses are the major aetiological agents of acute and chronic severe human diseases that place a tremendous burden on global public health and economy; however, for most viruses, effective prophylactics and therapeutics are lacking, in particular, broad-spectrum antiviral agents. Herein, we identified 2 secreted bacterial lipases from a Chromobacterium bacterium, named Chromobacterium antiviral effector-1 (CbAE-1) and CbAE-2, with a broad-spectrum virucidal activity against dengue virus (DENV), Zika virus (ZIKV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The CbAEs potently blocked viral infection in the extracellular milieu through their lipase activity. Mechanistic studies showed that this lipase activity directly disrupted the viral envelope structure, thus inactivating infectivity. A mutation of CbAE-1 in its lipase motif fully abrogated the virucidal ability. Furthermore, CbAE-2 presented low toxicity in vivo and in vitro, highlighting its potential as a broad-spectrum antiviral drug.

scholarly journals Olorofim Susceptibility Testing of 1,423 Danish Mold Isolates Obtained in 2018-2019 Confirms Uniform and Broad-Spectrum Activity

2020 ◽  
Vol 65 (1) ◽  
pp. e01527-20
Author(s):  
Karen Marie Thyssen Astvad ◽  
Karin Meinike Jørgensen ◽  
Rasmus Krøger Hare ◽  
Raluca Datcu ◽  
Maiken Cavling Arendrup
Keyword(s):  
Broad Spectrum ◽  
Susceptibility Testing ◽  
Population Data ◽  
Dihydroorotate Dehydrogenase ◽  
Content Type ◽  
Species Complexes ◽  
Upper Limits ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

ABSTRACTOlorofim is a novel antifungal drug in phase 2 trials. It has shown promising in vitro activity against various molds, except for Mucorales. Initially, we observed a broad range of EUCAST MICs for Aspergillus fumigatus. Here, we explored the MIC variability in more detail and prospectively investigated the susceptibility of contemporary clinical mold isolates, as population data are needed for future epidemiological cutoff (ECOFF) settings. Fifteen A. fumigatus isolates previously found with low/medium/high MICs (≤0.002 to 0.25 mg/liter) were tested repeatedly and EUCAST MICs read in a blinded fashion by three observers. pyrE, encoding the olorofim target enzyme dihydroorotate dehydrogenase (DHODH), was sequenced. A total of 1,423 mold isolates (10 Aspergillus species complexes [including 1,032 A. fumigatus isolates] and 105 other mold/dermatophyte isolates) were examined. Olorofim susceptibility (modal MIC, MIC50, MIC90, and wild-type upper limits [WT-ULs] [species complexes with ≥15 isolates]) was determined and compared to that of four comparators. MICs (mg/liter) were within two 2-fold dilutions (0.016 to 0.03) for 473/476 determinations. The MIC range spanned four dilutions (0.008 to 0.06). No significant pyrE mutations were found. Modal MIC/WT-UL97.5 (mg/liter) values were 0.03/0.06 (A. terreus and A. flavus), 0.06/0.125 (A. fumigatus and Trichophyton rubrum), and 0.06/0.25 (A. niger and A. nidulans). The MIC range for Scedosporium spp. was 0.008 to 0.25. Olorofim susceptibility was similar for azole-resistant and -susceptible isolates of A. fumigatus but reduced for A. montevidensis and A. chevalieri (MICs of >1). With experience, olorofim susceptibility testing is robust. The testing of isolates from our center showed uniform and broad-spectrum activity. Single-center WT-ULs are suggested.

scholarly journals The celecoxib derivative AR-12 has broad spectrum antifungal activity in vitro and improves the activity of fluconazole in a murine model of cryptococcosis

2016 ◽  
pp. AAC.01061-16 ◽  
Author(s):  
Kristy Koselny ◽  
Julianne Green ◽  
Louis DiDone ◽  
Justin P. Halterman ◽  
Annette W. Fothergill ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Small Molecules ◽  
Broad Spectrum ◽  
Murine Model ◽  
Antifungal Drugs ◽  
Dimorphic Fungi ◽  
New Class ◽  
Cancer Agent

Only one new class of antifungal drugs has been introduced into clinical practice in the last thirty years and, thus, the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib-derivative which has been tested in a Phase I clinical trial as an anti-cancer agent. AR-12 inhibits fungal acetyl CoA synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity including active against yeasts (e.g.,C. albicans, non-albicansCandidaspp.,C. neoformans); molds (e.g.,Fusarium,Mucor), and dimorphic fungi (Blastomyces,Histoplasma, andCoccidioides) with minimum inhibitory concentrations of 2-4 μg/mL. AR-12 is also active against azole- and echinocandin-resistantCandidaisolates and sub-inhibitory AR-12 concentrations increase susceptibility of fluconazole- and echinocandin-resistantCandidaisolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad spectrum antifungal activity.

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