galidesivir and favipiravir

Rabies virus remains an important burden of disease claiming an estimated 60,000 lives each year, mainly children, and having a huge economical and societal cost. Post-exposure prophylaxis (PEP) is highly effective, however in patients that present with neurological symptoms the case-fatality ratio is extremely high (>99%). During the last decades several attempts to identify potent and effective antivirals were made. Only a few of these demonstrated improvement in clinical signs in animal studies and none of the trials in humans showed significant efficacy. Here we explore novel opportunities to identify more potent anti-rabies molecules. In particular important progress has been made on antivirals against other Mononegavirales (paramyxoviruses, filoviruses) which should be an impetus to test and optimize these molecules towards anti-rabies virus therapies. Effective rabies antivirals for therapeutic use need to be molecules that can be dosed into the cerebrospinal fluid and that rapidly and potently block ongoing virus replication and as such stop the further spread of the virus. Antivirals for prophylactic use can also be envisaged and these should be able to prevent infection of peripheral nerve cells and should have the potential to replace the current anti-rabies immunoglobulins that are used in PEP.

Topics: Adenine; Adenosine; Adenosine Monophosphate; Alanine; Amides; Antiviral Agents; Drug Repositioning; Humans; Post-Exposure Prophylaxis; Pyrazines; Pyrrolidines; Rabies; Rabies virus

The 2014-2015 outbreak of Ebola virus disease is the largest epidemic to date in terms of the number of cases, deaths, and affected areas. In October 2015, no antiviral agents had proven antiviral efficacy in patients. However, in September 2014, the World Health Organization inventoried and has since regularly updated a list of potential drug candidates with demonstrated antiviral efficacy in in vitro or animal models. This includes agents belonging to various therapeutic classes, namely direct antiviral agents (favipiravir and BCX4430), a combination of antibodies (ZMapp), type I interferons, RNA interference-based drugs (TKM-Ebola and AVI-7537), and anticoagulant drugs (rNAPc2). Here, we review the pharmacokinetic and pharmacodynamic information presently available for these drugs, using data obtained in healthy volunteers for pharmacokinetics and data obtained in human clinical trials or animal models for pharmacodynamics. Future studies evaluating these drugs in clinical trials are critical to confirm their efficacy in humans, propose appropriate doses, and evaluate the possibility of treatment combinations.

Topics: Adenine; Adenosine; Amides; Animals; Antiviral Agents; Disease Outbreaks; Ebolavirus; Healthy Volunteers; Hemorrhagic Fever, Ebola; Humans; Models, Animal; Purine Nucleosides; Pyrazines; Pyrrolidines

The current Ebola virus outbreak is unprecedented in its scope and international impact. Given that there are currently no approved antivirals to treat Ebola virus, there is urgency to conduct more rapid development and evaluation of Ebola antivirals. Recently, the World Health Organization identified a number of antivirals as high priority to include AVI-6002 (AVI-7537 and AVI-7539), BCX4430, brincidofovir, favipiravir, and TKM-100802. This review describes these chemically synthesized inhibitors of Ebola virus, relevant patent development and gives an update on their current status.

Topics: Adenine; Adenosine; Amides; Antiviral Agents; Cytosine; Drug Discovery; Ebolavirus; Hemorrhagic Fever, Ebola; Humans; Organophosphonates; Patents as Topic; Purine Nucleosides; Pyrazines; Pyrrolidines

Since the outbreak emerged in November 2019, no effective drug has yet been found against SARS-CoV-2. Repositioning studies of existing drug molecules or candidates are gaining in overcoming COVID-19. Antiviral drugs such as remdesivir, favipiravir, ribavirin, and galidesivir act by inhibiting the vital RNA polymerase of SARS-CoV-2. The importance of in silico studies in repurposing drug research is gradually increasing during the COVID-19 process. The present study found that especially ribavirin triphosphate and galidesivir triphosphate active metabolites had a higher affinity for SARS-CoV-2 RNA polymerase than ATP by molecular docking. With the Molecular Dynamics simulation, we have observed that these compounds increase the complex's stability and validate the molecular docking results. We also explained that the interaction of RNA polymerase inhibitors with Mg

Topics: Adenine; Adenosine; Adenosine Monophosphate; Alanine; Amides; Antiviral Agents; COVID-19 Drug Treatment; Drug Repositioning; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Pyrazines; Pyrrolidines; Ribavirin; RNA, Viral; SARS-CoV-2

Understanding the effects of metabolism on the rational design of novel and more effective drugs is still a considerable challenge. To the best of our knowledge, there are no entirely computational strategies that make it possible to predict these effects. From this perspective, the development of such methodologies could contribute to significantly reduce the side effects of medicines, leading to the emergence of more effective and safer drugs. Thereby, in this study, our strategy is based on simulating the electron ionization mass spectrometry (EI-MS) fragmentation of the drug molecules and combined with molecular docking and ADMET models in two different situations. In the first model, the drug is docked without considering the possible metabolic effects. In the second model, each of the intermediates from the EI-MS results is docked, and metabolism occurs before the drug accesses the biological target. As a proof of concept, in this work, we investigate the main antiviral drugs used in clinical research to treat COVID-19. As a result, our strategy made it possible to assess the biological activity and toxicity of all potential by-products. We believed that our findings provide new chemical insights that can benefit the rational development of novel drugs in the future.

Topics: Adenine; Adenosine; Adenosine Monophosphate; Alanine; Amides; Antiviral Agents; Chloroquine; COVID-19; COVID-19 Drug Treatment; Drug Design; Drug Discovery; Humans; Metabolic Networks and Pathways; Molecular Docking Simulation; Nitro Compounds; Pyrazines; Pyrrolidines; Ribavirin; SARS-CoV-2; Thiazoles

The pandemic outbreak of a new coronavirus (CoV), SARS-CoV-2, has captured the world's attention, demonstrating that CoVs represent a continuous global threat. As this is a highly contagious virus, it is imperative to understand RNA-dependent-RNA-polymerase (RdRp), the key component in virus replication. Although the SARS-CoV-2 genome shares 80% sequence identity with severe acute respiratory syndrome SARS-CoV, their RdRps and nucleotidyl-transferases (NiRAN) share 98.1% and 93.2% identity, respectively. Sequence alignment of six coronaviruses demonstrated higher identity among their RdRps (60.9%-98.1%) and lower identity among their Spike proteins (27%-77%). Thus, a 3D structural model of RdRp, NiRAN, non-structural protein 7 (nsp7), and nsp8 of SARS-CoV-2 was generated by modeling starting from the SARS counterpart structures. Furthermore, we demonstrate the binding poses of three viral RdRp inhibitors (Galidesivir, Favipiravir, and Penciclovir), which were recently reported to have clinical significance for SARS-CoV-2. The network of interactions established by these drug molecules affirms their efficacy to inhibit viral RNA replication and provides an insight into their structure-based rational optimization for SARS-CoV-2 inhibition.

Topics: Adenine; Adenosine; Amides; Antiviral Agents; Betacoronavirus; Binding Sites; Coronavirus Infections; COVID-19; Humans; Molecular Docking Simulation; Nucleotidyltransferases; Pandemics; Pneumonia, Viral; Protein Structure, Tertiary; Pyrazines; Pyrrolidines; RNA-Dependent RNA Polymerase; SARS-CoV-2

We started a study on the molecular docking of six potential pharmacologically active inhibitors compounds that can be used clinically against the COVID-19 virus, in this case, remdesivir, ribavirin, favipiravir, galidesivir, hydroxychloroquine and chloroquine interacting with the main COVID-19 protease in complex with a COVID-19 N3 protease inhibitor. The highest values of affinity energy found in order from highest to lowest were chloroquine (CHL), hydroxychloroquine (HYC), favipiravir (FAV), galidesivir (GAL), remdesivir (REM) and ribavirin (RIB). The possible formation of hydrogen bonds, associations through London forces and permanent electric dipole were analyzed. The values of affinity energy obtained for the hydroxychloroquine ligands was -9.9 kcal/mol and for the chloroquine of -10.8 kcal/mol which indicate that the coupling contributes to an effective improvement of the affinity energies with the protease. Indicating that, the position chosen to make the substitutions may be a pharmacophoric group, and cause changes in the protease.

Topics: Adenine; Adenosine; Adenosine Monophosphate; Alanine; Amides; Antiviral Agents; Betacoronavirus; Binding Sites; Chloroquine; Coronavirus 3C Proteases; Coronavirus Infections; COVID-19; COVID-19 Drug Treatment; Cysteine Endopeptidases; Drug Interactions; Humans; Hydrogen Bonding; Hydroxychloroquine; Ligands; Molecular Docking Simulation; Nanotechnology; Pandemics; Pneumonia, Viral; Protease Inhibitors; Pyrazines; Pyrrolidines; Ribavirin; SARS-CoV-2; Static Electricity; Viral Nonstructural Proteins