Drug Sofosbuvir Research Articles

Effect of direct-acting antivirals on the titers of human pegivirus 1 during treatment of chronic hepatitis C patients.

Human pegivirus 1 coinfections are common in hepatitis C virus (HCV) patients, persisting for years. However, little is known about how pegivirus coinfections are affected by treatment with pangenotypic direct-acting antivirals (DAAs) against HCV. We identified human pegivirus by metagenomic analysis of chronic HCV patients undergoing protease, NS5A, and polymerase inhibitor treatment, in some patients with the addition of pegylated interferon, and followed viral kinetics of both viruses to investigate treatment effects. Only during HCV DAA treatment regimens that included the more broad-spectrum drug sofosbuvir could we detect a consistent decline in pegivirus titers that, however, rebounded to pretreatment levels after treatment cessation. The addition of pegylated interferon gave the highest effect with pegivirus titers decreasing to below the assay detection limit, but without clearance. These results reveal the limited effect of frontline HCV drugs on the closest related human virus, but sofosbuvir appeared to have the potential to be repurposed for other viral diseases.

Pig Liver Cytosolic Carboxylesterase 1 and Its Inhibition by Remdesivir and Sofosbuvir

AbstractPig carboxylesterases (CESs) are recognized as enzymes that metabolize xenobiotics, and many drugs used in pig breeding that contain ester groups can be hydrolyzed by CESs. However, there are a limited number of publications focused on the molecular weight, inhibitor effects, and enzyme kinetics of porcine cytosolic carboxylesterase. This study presents the first investigation of the presence, kinetics, inhibition, and amino acid sequence of CES1, the major cytosolic CES isozyme in pig liver. The molecular weight of pig liver cytosolic CES1 was estimated to be approximately 179 kDa, and the amino acid sequence of the enzyme subunit was determined. The inhibition of CES1 by the antiviral drugs remdesivir and sofosbuvir was studied, and the IC50 values were determined. The results indicate that remdesivir and sofosbuvir can act as potent modulators of CES1. The inhibitors exhibited mixed‐type inhibition on pig liver cytosol CES1. It was found that the affinity of the remdesivir and sofosbuvir for free enzyme is greater than that for the enzyme‐substrate complex. A spectrofluorimetric method confirmed the inhibition findings, as the fluorescence intensity of remdesivir decreased upon interaction with the enzyme.

Novel Strategy for Screening Target Proteins by the Common Drugs─Sofosbuvir-Specific Profiling of HCV Patient Serum.

It is the scientific basis of precision medicine to study all of the targets of drugs based on the interaction between drugs and proteins. It is worth paying attention to unknown proteins that interact with drugs to find new targets for the design of new drugs. Herein, we developed a protein profiling strategy based on drug-protein interactions and drug-modified magnetic nanoparticles and took hepatitis C virus (HCV) and its corresponding drug sofosbuvir (SOF) as an example. A SOF-modified magnetic separation medium (Fe3O4@POSS@SOF) was prepared, and a gradient elution strategy was employed and optimized to profile specific proteins interacted with SOF. A series of proteomic analyses were performed to profile proteins based on SOF-protein interactions (SPIs) in the serum of HCV patients to evaluate the specificity of the profiling strategy. As a result, five proteins were profiled with strong SPIs and exhibited high relevance with liver tissue, which were potentially new drug targets. Among them, HSP60 was used to confirm the highly specific interactions between the SOF and its binding proteins by Western blotting analysis. Besides, 124 and 29 differential proteins were profiled by SOF material from three HCV patient serum and pooled 20 HCV patient serum, respectively, by comparing with healthy human serum. In comparison with those profiled by the polyhedral oligomeric silsesquioxane (POSS) material, differential proteins profiled by the SOF material were highly associated with liver diseases through GO analysis and pathway analysis. Furthermore, four common differential proteins profiled by SOF material but not by POSS material were found to be identical and expressed consistently in both pooled serum samples and independent serum samples, which might potentially be biomarkers of HCV infection. Taken together, our study proposes a highly specific protein profiling strategy to display distinctive proteomic profiles, providing a novel idea for drug design and development.

Solid-state vibrational circular dichroism for pharmaceutical applications: Polymorphs and cocrystal of sofosbuvir

X-ray diffraction is a commonly used technique in the pharmaceutical industry for the determination of the atomic and molecular structure of crystals. However, it is costly, sometimes time-consuming, and it requires a considerable degree of expertise. Vibrational circular dichroism (VCD) spectroscopy resolves these limitations, while also exhibiting substantial sensitivity to subtle modifications in the conformation and molecular packaging in the solid state. This study showcases VCD’s ability to differentiate between various crystal structures of the same molecule (polymorphs, cocrystals). We examined the most effective approach for producing high-quality spectra and unveiled the intricate link between structure and spectrum via quantum-chemical computations. We rigorously assessed, using alanine as a model compound, multiple experimental conditions on the resulting VCD spectra, with the aim of proposing an optimal and efficient procedure. The proposed approach, which yields reliable, reproducible, and artifact-free results with maximal signal-to-noise ratio, was then validated using a set comprising of three amino acids (serine, alanine, tyrosine), one hydroxy acid (tartaric acid), and a monosaccharide (ribose) to mimic active pharmaceutical components. Finally, the optimized approach was applied to distinguish three polymorphs of the antiviral drug sofosbuvir and its cocrystal with piperazine. Our results indicate that solid-state VCD is a prompt, cost-effective, and easy-to-use technique to identify crystal structures, demonstrating potential for application in pharmaceuticals. We also adapted the cluster and transfer approach to calculate the spectral properties of molecules in a periodic crystal environment. Our findings demonstrate that this approach reliably produces solid-state VCD spectra of model compounds. Although for large molecules with many atoms per unit cell, such as sofosbuvir, this approach has to be simplified and provides only a qualitative match, spectral calculations, and energy analysis helped us to decipher the observed differences in the experimental spectra of sofosbuvir.

A new fluorescence probe for sofosbuvir analysis in dosage form and spiked human plasma.

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5μg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.

Features of NK cell phenotype virus genotype-driven chronic viral hepatitis C

Elimination of the hepatitis C virus (HCV) due to direct antiviral drug (DAD) action affects alteration in virus phenotype and, accordingly, NK cell functional activity. However, the published data are very contradictory. The aim of the study was to investigae alterations in NK cell subset phenotype after DAD treatment of HCV genotype-dependent chronic viral hepatitis C (CVHC) patients. Materials and methods. 111 CVHC patients and 21 healthy volunteers were examined. The diagnosis was established on epidemiological, clinical and laboratory data. All 111 subjects with CVHC received direct antiviral drugs Sofosbuvir and Velpatasvir for 12 weeks. The study of the NK cell phenotypes wwas analyzed by multicolor flow cytometry. Results. A decreased count of cytokine-producing along with increased frequency of cytotoxic NK cells were found in CVHC patients blood samples with various HCV genotypes prior to DAD treatment. The imbalance of cytotoxic cells with a high level of functional activity was also found in CVHC patients regardless of HCV genotype. The patients with HCV genotypes 1 and 3 showed significantly increased level of immunoregulatory NK cells. In addition, increased count of glycohydrolase (CD38) and ecto-5'-nucleotidase (CD73)-expressing NK cells were found in patients with HCV genotypes 1 and 3. Hence, such alterations in NK cell phenotype in CVHC patients were presented as sustained high viral load which peaking at carriers of HCV genotype 1 that was minimal in patients with HCV genotype 2. The most prominent change in NK cells after DAD treatment was found in CVHC patients with HCV genotype 2 (normalization of CD8-expressing NK cell subset composition and count). Only patients with HCV genotype 2 after treatment had increased frequencies of peripheral blood double-negative CD38–CD73– NK cells. Patients with HCV genotypes 1 and 3 also showed minimally improved in NK cell subset composition after DAD treatment. Conclusion. Evaluation of specific changes in NK cell phenotype during DAD treatment of CVHC patients driven by HCV genotype undoubtedly is of importance and high relevance. The results obtained are novel and complement the insights into CVHC immunopathogenesis. Analysis of NK cell phenotypes and functional activity in patients with CVHC may promote development of new methods for treating HCV infection.

Spectroscopic study to verify the anti-hepatitis C virus (HCV) treatment through a delivery system of the sofosbuvir drug on chitosan and pycnogenol nanoparticles surface

The target of the current study is to create a novel hybrid nanocomposite (Cs@Pyc.SOF) by combining the anti-hepatitis C virus (HCV) drug sofosbuvir with the nano antioxidant pycnogenol (Pyc) and nano biomolecules like chitosan nanoparticles (Cs NPs). The characterization procedure works to verify the creation of nanocomposite (NCP) using several different techniques. UV–Vis spectroscopy is used to measure SOF loading efficiency. The various concentrations of the SOF drug were used to determine the binding constant rate Kb, which was found to be 7.35 ± 0.95 min−1 with an 83% loading efficiency. At pH 7.4, the release rate was 80.6% after two hours and 92% after 48 h, whereas at pH 6.8, it was 29% after two hours and 94% after 48 h. After 2 and 48 h, the release rate in water was 38% and 77%, respectively.. The SRB technique for fast screening is used for the cytotoxicity test, where the investigated composites show a safety status and high viability against the examined cell line. The cytotoxicity assay of the SOF hybrid materials has been identified with cell lines like mouse normal liver cells (BNL). So, Cs@Pyc.SOF was recommended as a substitute medication for the therapy of HCV, but the results need clinical studies.

Efficacy of Daclatasvir and Half Dose Sofosbuvir in the Treatment of Hepatitis –C Virus Infection in Patients of Maintanance Hemodialysis-3 Years Trial in A Tertiary Renal Center

Background: Hepatitis C virus (HCV) infection in end-stage renal disease (ESRD) heralds a bad outcome. Directly acting antiviral (DAA) drugs sofosbuvir along with daclatasvir are very effective in the management of HCV infection. Sofosbuvir is excreted mainly through the kidneys. There is sparse data worldwide on the use of sofosbuvir based drug regimens in ESRD patients having chronic hepatitis C (CHC) virus infection.This study was designed to evaluate the efficacy of half dose sofosbuvir in the management of HCV infection in ESRD patients on maintenance hemodialysis (MHD). Methods: This clinical trial was conducted among 125 ESRD patients on MHD at Gonoshasthaya dialysis center, Dhanmondi, Dhaka from July 2019 to June 2022. Total 125 HCV positive patient with ESRD on MHD were included in this study; all the patients underwent HCV-RNA PCR test. Patients with detectable HCV RNA were observed for six months without antiviral drugs to identify the occurrence of spontaneous clearance of virus. Patients who had detectable HCV-RNA after six months were treated with sofosbuvir(200 mg) and daclatasvir (60 mg), irrespective of genotype. The drugs were given daily for 12 weeks. All the patients were on regular follow up at two weeks interval. Blood counts, liver function, creatinine phosphokinase and serum amylase values were evaluated periodically; virological response was assessed by HCV-RNA after 12 weeks of antiviral treatment. Results: During the observation period, 29 (23.2%) patients had spontaneous virus clearance with an undetectable HCV-RNA. In the remaining 96 patients, the median HCV-RNA level was 2.76×104 (1.56 ×103– 1.89×106)I IU. Twelve weeks after the treatment, 91 (94.8%) patients achieved sustained virological response (SVR) with undetectable HCV-RNA. All patients tolerated the DAAs well and none of the patients reported any serious adverse events. No patient discontinued antiviral therapy due to side effects. Patients who attained SVR with DAA, after 6 months we repeated HCV-RNA in 30 patients, in majority of them (28, 93.3%), HCV-RNA were undetected but in 2 (6.7%) patients,HCV-RNA were detected again. Conclusion: Daclatasvir along with half-dose sofosbuvir are safe and effective in the treatment of CHC patients with ESRD on MHD. Half dose sofosbuvir regimen can reduce the cost of treatment of HCV in ESRD patients in developing countries like Bangladesh, where cost is a significant barrier to HCV treatment. J Bangladesh Coll Phys Surg 2023; 41: 102-107

Electrodermal measurement of acupuncture points for testing daily doses of sofosbuvir in patients with chronic hepatitis C virus infection

Acupuncture has been practiced widely for treating different medical conditions. The basis of the acupuncture method is the doctrine of acupuncture points, one of the features of which is their unique electrical properties on the measurement of which the methods of electropuncture diagnostics are based. The purpose of the study was to explore the possibilities of a medicament testing technique for determining daily doses of the antiviral drug Sofosbuvir and comparing the tested daily doses of Sofosbuvir with the level of viral load in the blood of patients with chronic hepatitis C virus infection. Medicament testing of Sofosbuvir was performed on two points of point of acupunctures. This pilot study included 61 patients diagnosed with chronic hepatitis C virus infection. Electrodermal measurement points of acupuncture of Liver meridian and EAV Circulation meridian and the correlation between tested doses of Sofosbuvir and viral load in the patients’ blood were analyzed. The points of acupuncture of Liver and EAV Circulation meridians demonstrated the possibility to apply them as measuring points to determine daily doses of Sofosbuvir. Patients with chronic hepatitis C virus infection showed a significant positive correlation between tested daily doses of Sofosbuvir and viral load, which was gradually lost with an increase in viral load. The mean values of the tested doses of Sofosbuvir did not vary in different PA and significantly differed depending on viral load. This study showed that points of acupuncture serve as a diagnostic window in a process of medicament testing and can help to determine the daily doses of the antiviral drugs and also serve as an indirect method for assessing the level of viral load in patients with chronic hepatitis C virus infection. There is the correlation between the tested doses of Sofosbuvir and viral load levels in these patients.

Cheminformatics study of some indole compounds through QSAR modeling, ADME prediction, molecular docking, and molecular dynamic simulation to identify novel inhibitors of HCV NS5B protease

The hepatitis C virus is a viral disease that causes cirrhosis and hepatocellular carcinoma in the liver. Since the virus's discovery, significant therapeutic advances have been made. Notwithstanding, its upsurge necessitates the development of novel approaches to combating this disease. Recent studies have seen a rise in the value of plant compounds in the establishment of novel, efficient, and cost-efficient anti-HCV medications. These factors have motivated us to continuously search for novel, potent anti-HCV inhibitors, ideally with mechanisms different from those used in conventional medicine. Several filtrations processes including ADMET, molecular docking, and molecular dynamics (MD) simulation were used to choose potent hits from plant molecules deposited in the PubChem database. The binding kinetics were explored using MD simulation studies performed for 100 ns using GROMACS-2018.1. which was done to validate and supplement the findings of the virtual screening. The selected hits (with PubChem CID of 3,560,948 and 4,754,183) had preferable molecular traits that suggested they might work well as HCV inhibitors and are term as effective potential hits. The MD study confirmed the stability of the identified hit with a binding energy of −111.724 ( ± 81.668) kj/mol and mechanisms different from the FDA-approved drug (sofosbuvir) used as a reference with a binding energy of −106.132 ( ± 78.008) kj/mol. This approach could aid in the establishment and identification of novel inhibitors in pharmaceutical discovery. Experimental assessments could indeed ascertain as to if the identified molecule can be employed as an anti-HCV drug to address the ailment and confirm the reliability of our in-silico studies.

Conveyance of sofosbuvir through vesicular lipid nanocarriers as an effective strategy for management of viral meningitis.

This study aimed to deliver a potential water-soluble antiviral drug (sofosbuvir) through optimized vesicular lipid nanocarriers (LNs) to the rat brain as a novel strategy against viral meningitis. A 23 factorial design approach was established to assess the effect of formulation composition and process variables on the physicochemical properties of the LNs. Sofosbuvir-loaded LNs (SLNs) were developed by lipid layer hydration method utilizing optimized parameters and evaluated for various in vitro characterizations like FTIR, DSC, XRD, FESEM, vesicle size, zeta potential, drug carrying capacity and drug release. Plasma and brain pharmacokinetic (PK) studies were conducted in Sprague-Dawley rats. FTIR data depicted the absence of any major interaction between the drug and the excipients. DSC revealed a sharp endothermic peak for the drug. XRD showed the amorphic nature of the SLNs. Optimized SLNs were spherical as depicted from FESEM with 42.43 nm size, -49.21 mV zeta potential, 8.31% drug loading and sustained drug release in vitro. Plasma/brain PK studies depicted significant improvement in key PK parameters, viz. AUC, AUMC, MRT, and Vd, compared to those for the free drug. A more than 3.5-fold increase in MRT was observed for optimized SLNs (11.2 h) in brain tissue compared to the free drug (3.7 h). Ex vivo hemolysis data confirmed the non-toxic nature of the SLNs to human red blood cells. In silico docking study further confirmed strong interaction between the drug and selected protein 4YXP (herpes simplex) with docking score of -7.5 and 7EWQ protein (mumps virus) with docking score of -7.3. The optimized SLNs may be taken for further in vivo studies to pave the way towards clinical translation.

Eco friendly stability indicating HPTLC method for simultaneous determination of sofosbuvir and ledipasvir in pharmaceutical tablets and HPTLC-MS characterization of their degradation products

Recently, the analytical community has shown increasing interest in developing more environment-friendly practices by eliminating or reducing the use of hazardous chemicals and solvents which are extremely dangerous to human health and the environment. Thus in this study, a simple, rapid, inexpensive and eco-friendly HPTLC method with densitometric detection was designed, optimized and validated for the simultaneous quantitation of the antiviral drugs sofosbuvir (SOF) and ledipasvir (LED) in pure powder, synthetic mixtures, combined pharmaceutical formulation and in the presence of their stressed degradation products with high sensitivity and no interference. The separation was carried out on silica gel F254 plates, using green mobile phase ethyl acetate: water: ethanol (94:5:1v/v/v) for development followed by densitometric detection of SOF and LED at 250 and 320 nm, respectively. Both drugs had second order polynomial calibration curves within ranges 100–5000 ng/spot and 100–3000 ng/spot for SOF and LED, respectively, with correlation coefficients >0.9998 and the limits of detection were 30 and 29 ng/spot and the limits of quantification were 90 and 88 ng/spot for SOF and LED, respectively. The method was validated in terms of linearity, accuracy, precision, selectivity, and robustness. The drugs were subjected to acidic and basic hydrolysis, oxidation and photolytic conditions as per ICH guidelines, followed by detection of the degradation products and structure elucidation of their fragments with the aid of the HPTLC-ESI- MS technique. The greenness of the proposed method was assessed using the analytical Eco-Scale as an assessment tool with a 93-point score. So, it is considered excellent green.

Sofosbuvir and its tri-phosphate metabolite inhibit the RNA-dependent RNA polymerase activity of non-structural protein 5 from the Kyasanur forest disease virus

Kyasanur forest disease is a neglected zoonotic disease caused by a single-stranded RNA-based flavivirus, the incidence of which was first recorded in 1957 in the Southern part of India. Kyasanur forest disease virus is transmitted to monkeys and humans through the infected tick bite of Haemophysalis spinigera. Kyasanur forest disease is a febrile illness, which in severe cases, results in neurological complications leading to mortality. The current treatment regimens are symptomatic and supportive, and no targeted therapies are available for this disease. In this study, we evaluated the ability of FDA-approved drugs sofosbuvir (and its active metabolite) and Dasabuvir to inhibit the RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus. NS5 protein containing the N-terminal methyl transferase domain and C-terminal RNA-dependent RNA polymerase domain was expressed in Escherichia coli, and RNA-dependent RNA polymerase activity was demonstrated with the purified protein. The RNA-dependent RNA polymerase assay conditions were optimized, followed by the determination of apparent Km,ATP to validate the enzyme preparation. Half maximal-inhibitory concentrations against RNA-dependent RNA polymerase activity were determined for Sofosbuvir and its active metabolite. Dasabuvir did not show detectable inhibition with the tested conditions. This is the first demonstration of the inhibition of RNA-dependent RNA polymerase activity of NS5 protein from the Kyasanur forest disease virus with small molecule inhibitors. These initial findings can potentially facilitate the discovery and development of targeted therapies for treating Kyasanur forest disease.

Synthesis, characterization, DFT studies, and molecular modeling of hydrazinelidene‐3‐oxo‐3‐(p‐olyl) propanal derivatives as potential candidate for Hepatitis B and C treatment

AbstractSerious liver conditions including cirrhosis, hepatocellular carcinoma, and liver failure can be brought on by hepatitis B and C (HBV and HCV) infection. In our study, compound H_B and H_E were synthesized, spectroscopically, theoretically characterized, and investigated as potential drug for HBV and HCV. The stability of the investigated compounds as well as their Inter‐ and intramolecular interactions were investigated using the density functional theory with the B3LYP/6‐311+G (d, p) basis set. Lower energy gaps for studied compounds indicate compound ds to be reactive. The maximal absorption wavelengths of the substances under investigation were ascertained using the UV absorption spectrum. The optical property of the compounds under investigation was also calculated. Various vibrational modes displayed by functional groups present in the examined compounds were considered. Thereafter, docking was performed to determine the compatibility of compounds in study with selected hepatitis B and C proteins in comparison to recommended drugs Sofosbuvir and lamivudine. The results of molecular docking were based on binding affinity. Compound H_E, with a binding affinity of ‐7.6 kcal/mol has more potential in treating hepatitis than H_B, which has a binding affinity of ‐7.1 kcal/mol and is also a better anti‐hepatic agent than standard drugs sofosbuvir and lamivudine with lower binding affinities. Hence, H_E has the potential to treat HBV and HCV.

Diastereo- and enantioselective synthesis of compounds with a trifluoromethyl- and fluoro-substituted carbon centre.

Molecules that contain one or more fluorine atoms are crucial to drug discovery. There are protocols available for the selective synthesis of different organofluorine compounds, including those with a fluoro-substituted or a trifluoromethyl-substituted stereogenic carbon centre. However, approaches for synthesizing compounds with a trifluoromethyl- and fluoro-substituent stereogenic carbon centre are far less common. This potentially impactful set of molecules thus remains severely underdeveloped. Here we introduce a catalytic regio-, diastereo- and enantioselective strategy for the preparation of homoallylic alcohols bearing a stereogenic carbon centre bound to a trifluoromethyl group and a fluorine atom. The process, which involves a polyfluoroallyl boronate and is catalysed by an in situ-formed organozinc complex, can be used for diastereodivergent preparation of tetrafluoro-monosaccharides, including ribose core analogues of the antiviral drug sofosbuvir (Sovaldi). Unexpected reactivity/selectivity profiles, probably originating from the trifluoromethyl- and fluoro-substituted carbon site, are discovered, foreshadowing other unique chemistries that remain unknown.

Discovery of SARS-CoV-2 antiviral synergy between remdesivir and approved drugs in human lung cells

SARS coronavirus 2 (SARS-CoV-2) has caused an ongoing global pandemic with significant mortality and morbidity. At this time, the only FDA-approved therapeutic for COVID-19 is remdesivir, a broad-spectrum antiviral nucleoside analog. Efficacy is only moderate, and improved treatment strategies are urgently needed. To accomplish this goal, we devised a strategy to identify compounds that act synergistically with remdesivir in preventing SARS-CoV-2 replication. We conducted combinatorial high-throughput screening in the presence of submaximal remdesivir concentrations, using a human lung epithelial cell line infected with a clinical isolate of SARS-CoV-2. This identified 20 approved drugs that act synergistically with remdesivir, many with favorable pharmacokinetic and safety profiles. Strongest effects were observed with established antivirals, Hepatitis C virus nonstructural protein 5A (HCV NS5A) inhibitors velpatasvir and elbasvir. Combination with their partner drugs sofosbuvir and grazoprevir further increased efficacy, increasing remdesivir’s apparent potency > 25-fold. We report that HCV NS5A inhibitors act on the SARS-CoV-2 exonuclease proofreader, providing a possible explanation for the synergy observed with nucleoside analog remdesivir. FDA-approved Hepatitis C therapeutics Epclusa® (velpatasvir/sofosbuvir) and Zepatier® (elbasvir/grazoprevir) could be further optimized to achieve potency and pharmacokinetic properties that support clinical evaluation in combination with remdesivir.

Drug Likeness Screening and Evaluation of Physicochemical Properties of Selected Medicinal Agents by Computer Aided Drug Design Tools

The current drug research techniques, combinatorial synthesis and high throughput screening, help in obtaining and pre-evaluating thousands of compounds in a short duration of time. Among the selected compounds, the best hit molecule becomes the lead, and the drug likeness property helps to optimize the selection. Lipinski's Rule of five is the most widely used filter in pre-evaluation of compounds, according to Lipinski's Rule of five the molecule with poor oral absorption and low permeation has the molecular weight >500, ClogP >5, hydrogen bond acceptor more than 10 and hydrogen bond donor more than 5. To evaluate the Rule of Five, the top selling drugs of 2018-19 were selected. Among the selected 56 drugs, 12 drugs (tenofovir disoproxil, sofosbuvir and ledipasvir, sofosbuvir/velpatasvir, trastuzumab, glecaprevir, pegtilgrastion, Lumacaftor/ ivacaftor, fluticasone propionate and salmetarol, elbasvir, darunavir ethanolate, Linagliptin, metformin, fluticasone furoate and vilanterol) did not fulfill the rule. The rule is very useful in selecting the better compound in chemolibraries, but should be used carefully and with certain criterion due to possible exclusion of promising compounds.

The analysis of immunoreactivity of individual B-cell epitopes of hepatitis C virus (Flaviviridae: Hepacivirus: Hepatitis С virus) NS4a antigen

Chronic viral hepatitis C (CHC) is a ubiquitous infectious disease, a significant limitation of which WHO attributes to the use of a new highly effective antiviral therapy. Previously, two B-cell epitopes were identified in NS4a antigen of the hepatitis C virus (HCV). It was shown that certain titers of antibodies (ABs) to the extended C-terminal epitope (1687-1718 a.a.) can predict a high probability of achieving a sustained virological response (SVR) to standard therapy with pegylated interferon-α and ribavirin.The aim of the work was to determine immunoreactivity of two B-cell epitopes (middle and C-terminal) of NS4a antigen, and to estimate a possible association of ABs to them with the achievement of SVR after standard interferon therapy and treatment with direct antiviral drugs (DAAs) daclatasvir and sofosbuvir (velpanat). Blood serum samples of patients with CHC (n = 113), of which 55 participants received standard interferon therapy, 50 received velpanate treatment, the remaining 8 received no therapy were examined. The middle B-cell epitope (positions 24-34 a.a.) of NS4a was synthesized by the solid-phase method, while the C-terminal epitope (34-54 a.a.) was obtained using genetically engineered techniques. Enzyme immunoassay (ELISA) testing of the sera collected before treatment was performed for the two selected epitopes according to the conventional methods. The antibodies to the C-terminal epitope were detected significantly more frequently than those to the middle one (p = 0.01) when analyzing the blood sera of patients (n = 113). The presence of ABs to the C-terminal epitope in the serum samples of participants who completed standard interferon therapy was associated with the achievement of SVR (p = 0.0245). In the blood sera of participants who completed therapy with velpanate, an association of the presence of ABs to the C-terminal epitope with the achievement of SVR was also established (p < 0.0001). The presence of ABs to the middle B epitope was not associated with the achievement of SVR, regardless of the therapy used. The observed difference in the immunoreactivity of the two B-cell determinants may be associated with the localization of the nearest Th-epitopes, the sensitivity of NS4a antigen to proteolytic enzymes, and the peculiarities of epitope presentation by antigen-presenting cells. However, it should be noted that the immunoreactivity of the middle B-epitope is poorly studied. Although the association of ABs to the C-terminal epitope with the achievement of SVR has been shown by several scientific teams, the detailed molecular mechanism of their influence on the effectiveness of therapy is unclear. In CHC, ABs to the C-terminal epitope of NS4a are produced more frequently than those to the median epitope. The presence of ABs to the C-terminal epitope is a predictive marker of a high probability of achieving SVR, regardless of the type of therapy and antibody titer.

Sofosbuvir adsorption onto activated carbon derived from argan shell residue: Optimization, kinetic, thermodynamic and theoretical approaches

Activated carbon (AC) obtained from argan shell residue (ASR) was studied for the removal of the drug sofosbuvir from the liquid phase. The operating parameters including pH, adsorbent dosage, and sofosbuvir concentration were optimized with a Box Behnken design (B.B.D) using the response surface methodology (R.S.M.) approach. The results show a maximum removal at room temperaure of 54.5 mg.g−1 (99.63%) of sofosbuvir at pH 7, AC mass 0.5 g.L−1, and sofosbuvir concentration 0.1 mM. The adsorption investigation indicated that the process is well described by Freundlish isotherm model with R2 = 98.2%. Thermodynamic parameters, including ΔG°, ΔH°, and ΔS°, were also studied. The adsorption kinetics follows pseudo 2nd order. The produced AC was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). To better understand the adsorption mechanism and dynamic behavior of sofosbuvir, an oral nucleoside analog and potent inhibitor of the hepatitis C virus, we applied the density functional theory (DFT) approach, Monte Carlo simulations, and molecular dynamics (MD) simulations to examine the impact of different adsorption sites, adsorption energy, and mechanism. The moisture content H(%), volatile matter Vm, and iodine value in AC were also evaluated. The results indicate that argan shell-based AC is a promising candidate for the adsorption procedure due to its low cost and higher adsorption capacity for sofosbuvir removal from the liquid phase.

Biocatalytic Asymmetric Construction of Secondary and Tertiary Fluorides from β-Fluoro-α-Ketoacids.

Fluorine is a critical element for the design of bioactive compounds, driving advances in selective and sustainable fluorination. However, stereogenic tertiary fluorides pose a synthetic challenge and are thus present in only a few approved drugs (fluticasone, solithromycin, and sofosbuvir). The aldol reaction of fluorinated donors provides an atom-economical approach to asymmetric C-F motifs via C-C bond formation. We report that the type II pyruvate aldolase HpcH and engineered variants perform addition of β-fluoro-α-ketoacids (including fluoropyruvate, β-fluoro-α-ketobutyrate, and β-fluoro-α-ketovalerate) to diverse aldehydes. The reactivity of HpcH towards these fluoro-donors grants access to enantiopure secondary or tertiary fluorides. In addition to representing the first synthesis of tertiary fluorides via biocatalytic carboligation, the afforded products could improve the diversity of fluorinated building blocks and enable the synthesis of fluorinated drug analogs.