Broad-spectrum Antiviral Agent Research Articles

Eco-Friendly and Low-Cost Synthesis of Transparent Antiviral- and Antibacterial-Coated Films Based on Cu2O and MIL-53(Al).

This research presents the development of an innovative antimicrobial coating consisting of cuprous oxide (Cu2O) integrated with the metal-organic framework MIL-53(Al) through an eco-friendly and low-cost synthesis method that employs glucose as a reducing agent under mild conditions. The microstructural properties of the composite materials were characterized by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The antibacterial efficacy of the Cu2O-MIL-53(Al) (CuM) composite was assessed against Escherichia coli and Staphylococcus aureus, achieving a reduction efficacy of 99.99% with 5% copper incorporated into the MIL-53(Al) framework within a contact time of 24 h. The incorporation of CuM into a macromolecular host matrix of polyurethane-carboxymethylcellulose (CuM/PUD-CMC), applied as a coating on a low-cost plastic film, produced a transparent film with 87.10% transparency. This coating demonstrated a 99.99% reduction in E. coli and S. aureus populations within a contact time of 24 h. The CuM/PUD-CMC coating demonstrated substantial antiviral efficacy, achieving inactivation rates of 99.35% for Human Coronavirus 229E, 99.40% for Influenza A virus, and 97.76% for Enterovirus 71 within a contact time of 5 min. The CuM nanoparticles exhibited low toxicity toward zebrafish while effectively eradicating bacteria and inactivating viruses. The proposed low-cost material and coating method demonstrate significant potential as a broad-spectrum antimicrobial and antiviral agent, highlighting its suitability for various applications in biomedical and healthcare formulations.

Broad-Spectrum Antiviral Agents against SARS-CoV-2 Variants Inhibit the Conserved Viral Protein Nsp1-RNA Interaction.

The ongoing global threats posed by COVID-19 pandemic, catalyzed by SARS-CoV-2, underscores the pressing need for effective antiviral strategies. The viral non-structural protein 1 (Nsp1) significantly influences pathogenicity by impeding host protein expression and enhancing viral RNA translation through its interaction with the stem-loop 1 (SL1) in the 5' untranslated region (UTR). We have developed a novel dual-luciferase reporter assay, designed to investigate the critical Nsp1-SL1 interaction, and identified P23E02 as a potential inhibitor. Our investigation, combining molecular docking studies and alanine mutagenesis, has unveiled that P23E02 disrupts Nsp1-40S ribosomal subunit interaction, liberating translational inhibition and empowering host antiviral responses. P23E02 exhibits antiviral efficacy against various sarbecoviruses, making it a promising candidate for combatting COVID-19 and related diseases. This study underscores the therapeutic potential of targeting the Nsp1/SL1 axis and lays the foundation for innovative antiviral interventions, ultimately fortifying global preparedness against future viral threats.

A Structural Investigation of the Interaction between a GC-376-Based Peptidomimetic PROTAC and Its Precursor with the Viral Main Protease of Coxsackievirus B3

The conservation of the main protease in viral genomes, combined with the absence of a homologous protease in humans, makes this enzyme family an ideal target for developing broad-spectrum antiviral drugs with minimized host toxicity. GC-376, a peptidomimetic 3CL protease inhibitor, has shown significant efficacy against coronaviruses. Recently, a GC-376-based PROTAC was developed to target and induce the proteasome-mediated degradation of the dimeric SARS-CoV-2 3CLPro protein. Extending this approach, the current study investigates the application of the GC-376 PROTAC to the 3CPro protease of enteroviruses, specifically characterizing its interaction with CVB3 3CPro through X-ray crystallography, NMR (Nuclear Magnetic Resonance) and biochemical techniques. The crystal structure of CVB3 3CPro bound to the GC-376 PROTAC precursor was obtained at 1.9 Å resolution. The crystallographic data show that there are some changes between the binding of CVB3 3CPro and SARS-CoV-2 3CLPro, but the overall similarity is strong (RMSD on C-alpha 0.3 Å). The most notable variation is the orientation of the benzyloxycarbonyl group of GC-376 with the S4 subsite of the proteases. NMR backbone assignment of CVB3 3CPro bound and unbound to the GC-376 PROTAC precursor (80% and 97%, respectively) was obtained. This information complemented the investigation, by NMR, of the interaction of CVB3 3CPro with the GC-376 PROTAC, and its precursor allows us to define that the GC-376 PROTAC binds to CVB3 3CPro in a mode very similar to that of the precursor. The NMR relaxation data indicate that a quench of dynamics of a large part of the protein backbone involving the substrate-binding site and surrounding regions occurs upon GC-376 PROTAC precursor binding. This suggests that the substrate cavity, by sampling different backbone conformations in the absence of the substrate, is able to select the suitable one necessary to covalently bind the substrate, this being the latter reaction, which is the fundamental step required to functionally activate the enzymatic reaction. The inhibition activity assay showed inhibition potency in the micromolar range for GC-376 PROTAC and its precursor. Overall, we can conclude that the GC-376 PROTAC fits well within the binding sites of both proteases, demonstrating its potential as a broad-spectrum antiviral agent.

Two novel compounds inhibit Flavivirus infection in vitro and in vivo by targeting lipid metabolism.

This study is the inaugural utilization of a lipid compound library in antiviral drug screening. Two lipid compounds, isobavachalcone (IBC) and corosolic acid (CA), emerged from the screening, exhibiting substantial inhibitory effects on the Japanese encephalitis virus (JEV) proliferation in vitro. In vivo experiments underscored their efficacy, with IBC and CA reducing viral loads in the brain and mitigating JEV-induced histopathological changes, effectively shielding mice from fatal JEV infection. Intriguingly, IBC and CA may activate 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK) by binding to its active site, curtailing the synthesis of lipid substances, and thus suppressing JEV proliferation. This indicates AMPK as a potential antiviral target. Remarkably, IBC and CA demonstrated suppression of multiple viruses, including Flaviviruses (JEV and Zika virus), porcine herpesvirus (pseudorabies virus), and coronaviruses (porcine deltacoronavirus and porcine epidemic diarrhea virus), suggesting their potential as broad-spectrum antiviral agents. These findings shed new light on the potential applications of these compounds in antiviral research.

Isolation, structural determination, and antiviral activities of a novel alanine-conjugated polyketide from Talaromyces sp.

Antiviral agents are highly sought after. In this study, a novel alkylated decalin-type polyketide, alaspelunin, was isolated from the culture broth of the fungus Talaromyces speluncarum FMR 16671, and its structure was determined using spectroscopic analyses (1D/2D NMR and MS). The compound was condensed with alanine, and its absolute configuration was determined using Marfey's method. Furthermore, the antiviral activity of alaspelunin against various viruses was evaluated, and it was found to be effective against both severe acute respiratory syndrome coronavirus 2 and pseudorabies (Aujeszky's disease) virus, a pathogen affecting pigs. Our results suggest that this compound is a potential broad-spectrum antiviral agent.

Development of 3'-Deoxy-3',4'-didehydro-nucleoside Prodrug Inhibitors of West Nile and Zika Viruses.

The antiviral enzyme viperin catalyzes the formation of 3'-deoxy-3',4'-didehydro-cytidine-5'-triphosphate (ddhCTP). ddhCTP is incorporated into viral genomes and terminates genomic replication to confer broad-spectrum antiviral effects. We have previously utilized phosphoramidate pronucleotide (ProTide) technology to enable metabolic production of ddhCTP in cells from an exogenously dosed 3'-deoxy-3',4'-didehydro-cytidine ProTide, which confers inhibitory activity against West Nile virus (WNV) and Zika virus (ZIKV). Herein, we synthesized 3'-deoxy-3',4'-didehydro-nucleosides containing all native nucleobases (thymine, uracil, adenine, guanine, and hypoxanthine), elaborated each to a ProTide, and measured their activity for controlling WNV and ZIKV infection. In comparison to the ddhC ProTide, we found that the ProTides of 3'-deoxy-3',4'-didehydro-guanosine and 3'-deoxy-3',4'-didehydro-adenosine possess 2- and 4-fold greater antiviral effects against ZIKV, respectively. Collectively, this work advances the development of 3'-deoxy-3',4'-didehydro nucleosides as promising compounds for further development into broad-spectrum antiviral agents.

Safety, tolerability and pharmacokinetics of ASC10, a novel oral double prodrug of a broad-spectrum antiviral agent, β-d-N4-hydroxycytidine: results from a randomized, double-blind, placebo-controlled phase 1 study in Chinese healthy subjects

ABSTRACT Background Considering the rise of new SARS-CoV-2 variants that have reduced the efficacy of COVID-19 vaccines, the development of new antiviral medications for the disease has become increasingly necessary. In this study, ASC10, a novel antiviral prodrug, was studied in a phase 1 trial in healthy Chinese participants. Research design and methods Part 1 involved 60 participants, receiving 50–800 mg ASC10 or placebo twice daily for 5.5 days. Part 2, with 12 participants, explored ASC10 dosing in the fed/fasting states. Results ASC10-A, the main pharmacologically active metabolite, rapidly appeared in plasma (Tmax: 1.00–2.00 h) and decreased (t1/2: 1.10–3.04 h) without accumulation. The Cmax and area under the plasma concentration – time curve (AUC) of ASC10-A increased dose-dependently (50–800 mg BID) over 5.5 days, with no accumulation. The Tmax was slightly delayed in the fed state; however, the Cmax and AUC were similar between the fed and fasting states. Adverse events (AEs) were comparable (ASC10/placebo, 66.7%) and mostly mild (95%). Conclusion ASC10 was demonstrated to be safe and well tolerated and exhibited dose-proportional exposure and minimal food effects. Clinical trial registration www.clinicaltrials.gov identifier is NCT05523141.

The Novel A-Type Proanthocyanidin-Rich Phytocomplex SP4™ Acts as a Broad-Spectrum Antiviral Agent against Human Respiratory Viruses.

The appearance of new respiratory virus infections in humans with epidemic or pandemic potential has underscored the urgent need for effective broad-spectrum antivirals (BSAs). Bioactive compounds derived from plants may provide a natural source of new BSA candidates. Here, we investigated the novel phytocomplex formulation SP4™ as a candidate direct-acting BSA against major current human respiratory viruses, including coronaviruses and influenza viruses. SP4™ inhibited the in vitro replication of SARS-CoV-2, hCoV-OC43, hCoV-229E, Influenza A and B viruses, and respiratory syncytial virus in the low-microgram range. Using hCoV-OC43 as a representative respiratory virus, most of the antiviral activity of SP4™ was observed to stem primarily from its dimeric A-type proanthocyanidin (PAC-A) component. Further investigations of the mechanistic mode of action showed SP4™ and its PAC-A-rich fraction to prevent hCoV-OC43 from attaching to target cells and exert virucidal activity. This occurred through their interaction with the spike protein of hCoV-OC43 and SARS-CoV-2, thereby interfering with spike functions and leading to the loss of virion infectivity. Overall, these findings support the further development of SP4™ as a candidate BSA of a natural origin for the prevention of human respiratory virus infections.

The antimicrobial peptide Sparamosin26–54 exhibits antiviral activity against three aquatic enveloped viruses through lipid-binding-mediated virus lysis

The aquaculture industry is faced with huge economic losses caused by various enveloped virus infections, such as white spot syndrome virus (WSSV), Rana grylio virus (RGV), and Anguillid Herpesvirus 1 (AngHV). The urgent need for readily available broad-spectrum antiviral agents has led to the exploration of antiviral peptides (AVPs), among which antimicrobial peptides (AMPs) with antiviral activity have attracted increasing attention. Sparamosin26–54 (derived from Scylla paramamosain) is a promising antimicrobial agent. In this study, we found that Sparamosin26–54 significantly inhibited WSSV transcription and replication (as indicated by VP28 gene and protein levels), irreversibly inactivated virions, and impeded viral entry before binding to the cell. Transmission electron microscopy observations showed that Sparamosin26–54 had a direct destructive effect on WSSV virions. Lipidomic analysis and ELISA assay highlighted that Sparamosin26–54 had a potent affinity for phosphatidic acid (PA) and phosphatidylserine (PS) of WSSV. Liposome leakage assays further revealed a pronounced effect of Sparamosin26–54 on membrane lipid compositions, emphasizing its efficacy against the other two enveloped viruses (RGV and AngHV), but not against the non-enveloped virus, American eel adomavirus (AEAdov). Notably, in three animal models of viral infection, Sparamosin26–54 reduced viral loads in tissues, increased survival, or decreased infection rates in a concentration-dependent manner. Importantly, Sparamosin26–54 showed no animal toxicity under different modes of administration and could maintain antiviral activity in the complex aquatic environment. Taken together, Sparamosin26–54 was proved to be effective against three enveloped viruses, possibly inducing viral lysis via lipid-binding, providing an alternative approach for combating enveloped virus infections.

Mechanistic Understanding of Dexamethasone-Mediated Protection against Remdesivir-Induced Hepatotoxicity.

Remdesivir (RDV), a broad-spectrum antiviral agent, is often used together with dexamethasone (DEX) for hospitalized COVID-19 patients requiring respiratory support. Potential hepatic adverse drug reaction is a safety concern associated with the use of RDV. We previously reported that DEX cotreatment effectively mitigates RDV-induced hepatotoxicity and reduces elevated serum alanine aminotransferase and aspartate aminotransferase levels in cultured human primary hepatocytes (HPH) and hospitalized COVID-19 patients, respectively. Yet, the precise mechanism behind this protective drug-drug interaction remains largely unknown. Here, we show that through the activation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling, RDV induces apoptosis (cleavage of caspases 8, 9, and 3), autophagy (increased autophagosome and LC3-II), and mitochondrial damages (decreased membrane potential, respiration, ATP levels, and increased expression of Bax and the released cytosolic cytochrome C) in HPH. Importantly, cotreatment with DEX partially reversed RDV-induced apoptosis, autophagy, and cell death. Mechanistically, DEX deactivates/dephosphorylates p38, JNK, and ERK1/2 signaling by enhancing the expression of dual specificity protein phosphatase 1 (DUSP1), a mitogen-activated protein kinase (MAPK) phosphatase, in a glucocorticoid receptor (GR)-dependent manner. Knockdown of GR in HPH attenuates DEX-mediated DUSP1 induction, MAPK dephosphorylation, as well as protection against RDV-induced hepatotoxicity. Collectively, our findings suggest a molecular mechanism by which DEX modulates the GR-DUSP1-MAPK regulatory axis to alleviate the adverse actions of RDV in the liver. SIGNIFICANCE STATEMENT: The research uncovers the molecular mechanisms by which dexamethasone safeguards against remdesivir-associated liver damage in the context of COVID-19 treatment.

Polyethylene Glycol-Modified Cationic Liposome as a Promising Nano Spray for Acute Pneumonia Treatment.

Acute pneumonia (AP), triggered primarily by pathogens like bacteria and viruses, is a leading cause of human mortality. Ribavirin, a broad-spectrum antiviral agent, plays a pivotal role in the treatment of AP. However, its therapeutic use is hindered by the need for high dosages and the associated cardiac and hepatic toxicities. In this study, we synthesized polyethylene glycol-modified cationic liposomes to encapsulate ribavirin (RBV-PCL) and formulated it into a spray, aiming to enhance the effectiveness of RBV through respiratory administration. Lipopolysaccharide (LPS), a compound known to induce AP models in animals, was utilized in our research. Successfully, we established an acute pneumonia model in mice using aerosol inhalation. Through animal experiments, we investigated the therapeutic effects of RBV-PCL on mice with AP. In vivo studies revealed promising results. RBV-PCL effectively prolonged the survival of mice with AP, significantly reduced the levels of inflammatory markers such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and inhibited the infiltration of neutrophils in the lungs and spleens of mice. These findings suggest that RBV-PCL can effectively suppress the inflammatory response in mice with AP, thus holding significant potential as a novel therapeutic approach for the treatment of acute pneumonia.

The nucleoside analog 4'-fluorouridine suppresses the replication of multiple enteroviruses by targeting 3D polymerase.

Human enteroviruses are the major pathogens causing hand-foot-and-mouth disease in infants and young children throughout the world, and infection with enterovirus is also associated with severe complications, such as aseptic meningitis and myocarditis. However, there are no antiviral drugs available to treat enteroviruses infection at present. In this study, we found that 4'-fluorouridine (4'-FlU), a nucleoside analog with low cytotoxicity, exhibited broad-spectrum activity against infections of multiple enteroviruses with EC50 values at low micromolar levels, including coxsackievirus A10 (CV-A10), CV-A16, CV-A6, CV-A7, CV-B3, enterovirus A71 (EV-A71), EV-A89, EV-D68, and echovirus 6. With further investigation, the results indicated that 4'-FlU directly interacted with the RNA-dependent RNA polymerase of enterovirus, the 3D pol, and impaired the polymerase activity of 3D pol, hence inhibiting viral RNA synthesis and significantly suppressing viral replication. Our findings suggest that 4'-FlU could be promisingly developed as a broad-spectrum direct-acting antiviral agent for anti-enteroviruses therapy.

Using a Drug Repurposing Strategy to Virtually Screen Potential HIV-1 Entry Inhibitors That Block the NHR Domain of the Viral Envelope Protein gp41

Using a drug repurposing strategy, virtual screening of potential inhibitors of the NHR domain of the HIV-1 gp41 protein, a conserved region critical for the virus-cell membrane fusion and viral infectivity, was carried out. The used computational approach included: (1) molecular docking of this functionally significant region of the HIV-1 envelope with compounds from a library of bioactive molecules containing clinically approved drugs, experimental drugs, and investigational drug candidates; (2) assessing the binding affinity of these compounds to the therapeutic target; (3) molecular dynamics simulations of ligand/NHR-gp41 complexes; (4) calculations of the binding free energy followed by the analysis of molecular dynamics trajectories and selection of compounds promising to test for anti-HIV-1 activity. As a result, six compounds that exhibited the high binding affinity to the NHR domain of the HIV-1 gp41 protein and showed acceptable pharmacological properties were identified. The predicted compounds are assumed to form a promising basis for the development of new, effective and safe broad-spectrum antiviral agents able to inhibit the HIV-1 entry into the host cell.

Design, Synthesis, and Biological Evaluation of Novel Coumarin Analogs Targeted against SARS-CoV-2.

SARS-CoV, an RNA virus, is contagious and displays a remarkable degree of adaptability, resulting in intricate disease presentations marked by frequent genetic mutations that can ultimately give rise to drug resistance. Targeting its viral replication cycle could be a potential therapeutic option to counter its viral growth in the human body leading to the severe infectious stage. The Mpro of SARS-CoV-2 is a promising target for therapeutic development as it is crucial for viral transcription and replication. The derivatives of β-diketone and coumarin have already been reported for their antiviral potential and, thus, are considered as a potential scaffold in the current study for the computational design of potential analogs for targeting the viral replication of SARS-CoV-2. In our study, we used novel diketone-hinged coumarin derivatives against the SARS-CoV-2 MPro to develop a broad-spectrum antiviral agent targeting SARS-CoV-2. Through an analysis of pharmacokinetics and docking studies, we identified a list of the top 10 compounds that demonstrated effectiveness in inhibiting the SARS-CoV-2 MPro virus. On the basis of the pharmacokinetics and docking analyses, the top 5 novel coumarin analogs were synthesized and characterized. The thermodynamic stability of compounds KS82 and KS94 was confirmed by their molecular dynamics, and the stability of the simulated system indicated their inhibitory nature. Molecules KS82 and KS94 were further evaluated for their anti-viral potential using Vero E6 cells followed by RT-PCR assay against SARS-CoV-2. The test compound KS82 was the most active with the potential to inhibit SARS-CoV-2 replication in Vero E6 cells. These data indicate that KS82 prevents the attack of the virus and emerges as the primary candidate with promising antiviral properties.

Design, synthesis, and antiviral activity of 1-aryl-4-arylmethylpiperazine derivatives as Zika virus inhibitors with broad antiviral spectrum

Zika virus (ZIKV) disease has been given attention due to the risk of congenital microcephaly and neurodevelopmental disorders after ZIKV infection in pregnancy, but no vaccine or antiviral drug is available. Based on a previously reported ZIKV inhibitor ZK22, a series of novel 1-aryl-4-arylmethylpiperazine derivatives was designed, synthesized, and investigated for antiviral activity by quantify cellular ZIKV RNA amount using RT-qPCR method in ZIKV-infected human venous endothelial cells (HUVECs) assay. Structure-activity relationship (SAR) analysis demonstrated that anti-ZIKV activity of 1-aryl-4-arylmethylpiperazine derivatives is not correlated with molecular hydrophobicity, multiple new derivatives with pyridine group to replace the benzonitrile moiety of ZK22 showed stronger antiviral activity, higher ligand lipophilicity efficiency as well as lower cytotoxicity. Two active compounds 13 and 33 were further identified as novel ZIKV entry inhibitors with the potential of oral available. Moreover, both ZK22 and newly active derivatives also possess of obvious inhibition on the viral replication of coronavirus and influenza A virus at low micromolar level. In summary, this work provided better candidates of ZIKV inhibitor for preclinical study and revealed the promise of 1-aryl-4-arylmethylpiperazine chemotype in the development of broad-spectrum antiviral agents.

The α-dystroglycan N-terminus is a broad-spectrum antiviral agent against SARS-CoV-2 and enveloped viruses

The COVID-19 pandemic has shown the need to develop effective therapeutics in preparedness for further epidemics of virus infections that pose a significant threat to human health. As a natural compound antiviral candidate, we focused on α-dystroglycan, a highly glycosylated basement membrane protein that links the extracellular matrix to the intracellular cytoskeleton. Here we show that the N-terminal fragment of α-dystroglycan (α-DGN), as produced in E. coli in the absence of post-translational modifications, blocks infection of SARS-CoV-2 in cell culture, human primary gut organoids and the lungs of transgenic mice expressing the human receptor angiotensin I-converting enzyme 2 (hACE2). Prophylactic and therapeutic administration of α-DGN reduced SARS-CoV-2 lung titres and protected the mice from respiratory symptoms and death. Recombinant α-DGN also blocked infection of a wide range of enveloped viruses including the four Dengue virus serotypes, influenza A virus, respiratory syncytial virus, tick-borne encephalitis virus, but not human adenovirus, a non-enveloped virus in vitro. This study establishes soluble recombinant α-DGN as a broad-band, natural compound candidate therapeutic against enveloped viruses.

Targeting host-virus interactions: in silico analysis of the binding of human milk oligosaccharides to viral proteins involved in respiratory infections

Respiratory viral infections, a major public health concern, necessitate continuous development of novel antiviral strategies, particularly in the face of emerging and re-emerging pathogens. In this study, we explored the potential of human milk oligosaccharides (HMOs) as broad-spectrum antiviral agents against key respiratory viruses. By examining the structural mimicry of host cell receptors and their known biological functions, including antiviral activities, we assessed the ability of HMOs to bind and potentially inhibit viral proteins crucial for host cell entry. Our in silico analysis focused on viral proteins integral to host-virus interactions, namely the hemagglutinin protein of influenza, fusion proteins of respiratory syncytial and human metapneumovirus, and the spike protein of SARS-CoV-2. Using molecular docking and simulation studies, we demonstrated that HMOs exhibit varying binding affinities to these viral proteins, suggesting their potential as viral entry inhibitors. This study identified several HMOs with promising binding profiles, highlighting their potential in antiviral drug development. This research provides a foundation for utilizing HMOs as a natural source for designing new therapeutics, offering a novel approach in the fight against respiratory viral infections.

Insights into the sustainability of liquid chromatographic methods for favipiravir bioanalysis: a comparative study.

The introduction of favipiravir as a broad-spectrum antiviral agent, particularly in treating influenza and exploring its potential against COVID-19, emphasizes the necessity for efficient analytical methods. Liquid chromatography has emerged as a commonly utilized technique for quantifying favipiravir in biological fluids. However, the environmental and health concerns linked to classical analytical methods mean a transition toward green analytical chemistry is required. This study investigates the environmental impact of 19 liquid chromatographic methods utilized in the bioanalysis of favipiravir. Recognizing the importance of eco-friendly practices in pharmaceutical analysis, the study employs three widely accepted greenness assessment tools: Analytical Eco-Scale (AES), Green Analytical Procedure Index (GAPI), and Analytical Greenness Calculator (AGREE). Moreover, it incorporates a comprehensive evaluation on a global scale utilizing the whiteness assessment tool Red-Green-Blue 12 (RGB 12). The comprehensive evaluation aims to extend beyond traditional validation criteria and considerations of green chemistry, providing insights into the development of practically efficient, eco-friendly and economical analytical methods for favipiravir determination. This study emphasizes the necessity of planning for the environmental impact and overall sustainability of analytical methods before laboratory trials. Additionally, the integration of greenness/whiteness evaluation in method validation protocols is strongly advocated, emphasizing the importance of critical and global evaluations in analytical chemistry.

Paving new roads toward the advancement of broad-spectrum antiviral agents.

Broad-spectrum antivirals (BSAs) have the advantageous property of being effective against a wide range of viruses with a single drug, offering a promising therapeutic solution for the largely unmet need in treating both existing and emerging viral infections. In this review, we summarize the current strategies for the development of novel BSAs, focusing on either targeting the commonalities during the replication of multiple viruses or the systemic immunity of humans. In comparison to BSAs that target viral replication, these immuno-modulatory agents possess an expanded spectrum of antiviral activity. However, antiviral immunity is a double-edged sword, and maintaining immune homeostasis ultimately dictates the health status of hosts during viral infections. Therefore, establishing an ideal goal for immuno-modulation in antiviral interventions is crucial. Herein we propose a bionic approach for immuno-modulation inspired by mimicking bats, which possess a more robust immune system for combating viral invasions, compared to humans. In addition, we discuss an empirical approach to treat diverse viral infections using traditional Chinese medicines (TCMs), mainly through bidirectional immuno-modulation to restore the disrupted homeostasis. Advancing our understanding of both the immune system of bats and the mechanisms underlying antiviral TCMs will significantly contribute to the future development of novel BSAs.

Quantitative Analysis of Favipiravir by HPLC: Development and Validation

Favipiravir is a broad-spectrum oral antiviral agent and has been approved for the treatment of COVID-19 infection cases. It inhibits a protein known as RNA polymerase, which transcribes and replicates the viral RNA genome, causing the spread of the infection. The current study aimed to develop and validate a new analytical method utilizing HPLC in accordance with international requirements (ICH and FDA). The chromatographic conditions used to achieve good resolution and reproducibility were a mixture of acetonitrile and 0.1% phosphoric acid buffer in the ratio of 60 : 40 v/v as the mobile phase. The flow rate was 1.0 mL/min, the wavelength (λ) was determined at 250 nm, and a retention time was approximately 3 minutes for favipiravir. The HPLC analysis was performed on the Dionex 300 system equipped with a Phenomenex C8 (250 cm 4.6 mm) 5 μm column. The total runtime was 6.0 min. The findings indicated that the method had been validated satisfactorily. Across the concentration range of 0.10–0.75 mg/ml, the calibration curve revealed a linear relationship. The accuracy of the current method was to be 99.2%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.004 and 0.013 ppm, respectively. The standard and sample solution repeatability tests revealed that the procedure was precise and within acceptable ranges. The RSD% for the determination of precision was <2%. The results for robustness and solution stability were within acceptable limits. Finally, the new method provided an excellent result for all analytical method validation parameters and met the acceptance criteria. In addition, the new approach has a short run time and a retention time of around 4 minutes.