Antivirals

<p>Anti-viral; inhibitor of NS5A protein</p>

<p>Anti-viral; inhibitor of cytomegalovirus-terminase complex</p>

<p>N-Boc-protected -Guanidino Oseltamivir is a fine chemical that belongs to the group of versatile building blocks. It is a complex compound that has been used in research as a reagent and speciality chemical. N-Boc-protected -Guanidino Oseltamivir is an important intermediate for the synthesis of a variety of useful compounds, such as pharmaceuticals and natural products. This compound is also used as a reaction component in organic syntheses, especially for the preparation of high quality and useful scaffolds.</p>

<p>Non-nucleoside inhibitor of reverse transcriptase; anti-viral</p>

<p>Anti-viral; NS3/4A protease inhibitor</p>

<p>Atazanavir is an antiviral protease inhibitor, used in the anti-retroviral therapy of adult and sometimes paediatric patients infected with HIV. This drug inhibits the processing of viral Gag and Gag-pol polyproteins in HIV-1 infected cells by binding to the HIV-1 protease active site.</p>

<p>Dasabuvir is a non-nucleoside NS5B polymerase inhibitor with action on hepatitis C virus RNA replication and is used for treating hepatitis C in combination therapies.</p>

<p>Potent and selective inhibitor of influenza A and B sialidases. Zanamivir belongs to the class of drugs known as neuraminidase inhibitors. This compound is a sialic acid analogue that occupies viral neuraminidase active site, inhibits enzyme’s hydrolytic activity and cleavage of sialic acid residues from host cell surface glycans. It therefore prevents shedding newly produced virions from infected cell surface and reduces infection of surrounding cells. In in vitro studies with influenza A and B virus isolates, zanamivir inhibited the plaque formation by 50% in canine cells (MDCK) with concentrations between 0.004 and 0.014 μM and 0.02 and 16 μM, respectively.<br>Zanamivir hydrate is part of our Bio-X ™ Range. These products are aimed at life science researchers who need high quality ready to use products for assay development, screening or other R&amp;D work. With a solubility datasheet and convenient vials, all of our Bio-X ™ products are in stock across our global warehouses for rapid delivery and ease of use.</p>

<p>Dapivirine is a non-nucleoside reverse transcriptase inhibitor with action on HIV-1 reverse transcriptase and is used for preventing HIV infection through vaginal rings.</p>

<p>6-Fluoro-3-hydroxypyrazine-2-carboxamide is a potent RNA polymerase inhibitor, active against both RNA viruses in vitro and in vivo. A four-step approach to the synthesis of 6-Fluoro-3-hydroxypyrazine-2-carboxamide was reported in 2014. 6-Fluoro-3-hydroxypyrazine-2-carboxamide is commercialized and has recently been suggested for the treatment of mild cases of COVID-19.</p>

<p>Anti-viral; HIV protease inhibitor</p>

<p>Inhibitor of viral neuraminidase enzyme, effective against influenza A and B viruses. This antiviral compound inhibits neuraminidase-mediated cleavage of host cell sialic acids, which interact with newly synthesised virions from the host cell. This prevents virion budding from the host, resulting in inhibition of virion release and viral infection overall.</p>

<p>Raltegravir is an antiretroviral agent, which is a synthetic integrase inhibitor sourced from pharmaceutical research. Its mode of action involves the inhibition of the HIV-1 integrase enzyme, which is essential for the viral replication process. By blocking the strand transfer step of the integration of viral DNA into the host cell genome, Raltegravir prevents the proliferation of the virus within the host.</p>

<p>A compound with antiviral activity against Ebola virus that targets the surface-exposed glycoprotein and inhibits viral entry into host cells. In vitro studies in Vero cells revealed the compound inhibits the viral replication with EC50 of 0.38 µM.</p>

<p>CCR-5 chemokine receptor antagonist; inhibits HIV entry via gp120 protein</p>

<p>Cidofovir is an anti-viral agent that is used to treat Cytomegalovirus (CMV) retinitis in patients with AIDS. This drug suppresses CMV replication by inhibiting viral DNA synthesis.</p>

<p>Darunavir is a HIV-1 protease inhibitor used orally in the treatment of patients with multi-drug resistant HIV-1 infection (Ghosh, 2007). It has also been shown to be effective against other infectious diseases such as hepatitis C virus and SARS coronavirus. Metabolized by cytochrome P450 3A (CYP3A) isoenzymes, darunavir is often administered together with ritonavir that prolongs its bioavaiability, giving a terminal elimination half-life (t1/2) of 15 hours (Back, 2008). The effect of darunavir on natural compounds such as matrix proteins and toll-like receptor activity has also been studied via high performance liquid chromatography (HPLC) experiments.</p>

<p>Antiviral; Hepatitis C virus NS5A antagonist</p>

<p>Anti-retroviral; HIV protease inhibitor</p>

<p>Dolutegravir is an HIV-1 integrase inhibitor. Dolutegravir is used in the treatment of HIV-1 infections as it hampers the integration of the viral genome into the host DNA (Katlama, 2012). Active on a wide number of HIV-1 phenotypes, dolutegravir is highly bioavailable with an IC90 of more than 30 hours (Cottrell, 2013).</p>

<p>Boceprevir is a peptidomimetic, covalent inhibitor of NS3/4A serine protease from hepatitis C virus (HCV). Boceprevir also inhibits and acts as a substrate in the cytochrome P450 3A4 (CYP3A) metabolic pathway. Boceprevir was recently shown to inhibit the main protease Mpro (3CLpro) from SARS-CoV-2 with IC50 of 4.13 μM and EC50 of 1.31 μM.</p>

<p>Anti-viral; inhibits Hepatitis C virus NS3/4a protease</p>

<p>Nevirapine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) with action on HIV reverse transcriptase to block viral replication and is used for treating HIV/AIDS in combination therapies.</p>

<p>Tenofovir is an acyclic nucleoside phosphonate that exhibits anti-viral properties through its inhibition of reverse transcriptases. In particular, Tenofovir is a potent inhibitor of Human Immunodeficiency Virus (HIV) and chronic Hepatitis B Virus (HBV) reverse transcriptases, thus preventing the replication of genetic viral material. This property is beneficial in virus research areas and developing antiviral treatments. Once inside the body tenofovir is metabolized into its active form, tenofovir diphosphate, by the lysosomal protease cathepsin A, nucleotide kinases and adenylate kinases. <br>Tenofovir is part of our Bio-X ™ Range. These products are aimed at life science researchers who need high quality ready to use products for assay development, screening or other R&amp;D work. With a solubility datasheet and convenient vials, all of our Bio-X ™ products are in stock across our global warehouses for rapid delivery and ease of use.</p>

<p>Abacavir sulfate is an antiviral drug that belongs to the class of HIV protease inhibitors. It is used in combination with other antiretroviral drugs to treat HIV-1 infection. Abacavir sulfate inhibits viral replication by blocking the activity of HIV-1 protease, which is necessary for the production of new virus particles.<br>Abacavir sulfate is part of our Bio-X ™ Range. These products are aimed at life science researchers who need high quality ready to use products for assay development, screening or other R&amp;D work. With a solubility datasheet and convenient vials, all of our Bio-X ™ products are in stock across our global warehouses for rapid delivery and ease of use.</p>

<p>A competitive inhibitor of HCV NS3/4A protease that blocks viral replication. Efficacious in treating HCV-infected patients in combination with daclatasvir. Asunaprevir-resistant replicons are sensitive to NS5A replication complex inhibitor, suggesting potential combination therapy.</p>

<p>Rimantadine is an anti-viral drug that is used for the prevention of influenza A infection. This drug is an RNA synthesis inhibitor and exerts its effects on the viral replication cycle. Although not fully understood, it is said that the M2 gene may play a role in Rimantadine susceptibility.</p>

<p>Fosamprenavir calcium is an antiretroviral medication, which is derived from the prodrug of amprenavir. It is synthesized through chemical processes to enhance oral bioavailability and improve pharmacokinetic properties. Through its mode of action, fosamprenavir is converted in vivo to amprenavir, which acts as an inhibitor of the HIV-1 protease enzyme. By inhibiting this enzyme, it prevents the cleavage of the Gag-Pol polyprotein, disrupting viral replication and processing, ultimately leading to the production of immature, non-infectious viral particles.</p>

<p>Antiviral; nonpeptidic HIV-1 protease inhibitor</p>

<p>Inhibitor of HCV NS5A</p>

<p>GS 5734, also known as remdesivir is a nucleoside prodrug with broad spectrum antiviral activity against RNA viruses. As remdesivir / GS 5734 is a prodrug, it requires to be triphosphorylated by cellular kinases in order to compete with ATP for incorporation in newly replicated viral RNA. A major benefit of remdesivir in comparison with other antiviral nucleoside analogs is its resistance to proofreading exonucleases, which occur in coronaviruses. This means remdesivir can overcome the repair mechanism and preserve its antiviral activity. Remdesivir was reported to have a therapeutic as well as prophylactic efficacy in a mouse model infected with SARS-CoV-1.</p>

<p>Penciclovir is an antiviral agent and acyclic guanine derivative that has proven efficient in the treatment of Herpes Simplex type 1 and 2 (HSV1 and HSV2) infection. Penciclovir is transformed by the virus into an active derivative able to block the deoxyguanosine triphosphate substrate binding site of the HSV polymerase.</p>

<p>Anti-viral; HIV-1 protease inhibitor</p>

<p>Atazanavir is a HIV-1 protease inhibitor, used in the anti-retroviral therapy of adult and sometimes paediatric patients infected with HIV. In in vitro studies with human pulmonary epithelial cells, atazanavir has been studied as a potential inhibitor of SARS-CoV-2 Mpro protease, with the aim of halting viral replication.</p>

<p>Tenofovir disoproxil is a nucleotide analog reverse transcriptase inhibitor that is used to treat infections such as Hepatitis-B and HIV. This drug is an antiretroviral agent that blocks reverse transcriptase, blocking viral replication.</p>

<p>Famciclovir is a guanosine analogue antiviral agent that is used for the treatment of various herpesvirus infections, most commonly for herpes zoster. It works by inhibiting the replication of the herpes virus. Famciclovir prevents viral DNA synthesis by inhibiting the viral DNA polymerase and by blocking viral DNA replication. Its active form is penciclovir.</p>

<p>Anti-viral; capsid inhibitor</p>

<p>BMS 806 is used as an anti-viral agent. It has been shown to inhibit the replication of HIV. BMS 806 inhibits viral life by binding to the surface glycoproteins and inhibiting viral entry into cells. The drug also inhibits viral replication by preventing DNA transcription and translation.</p>

<p>GSK 2838232 is a HIV-1 maturation inhibitor with action on HIV-1 Gag protein cleavage and is used for research on HIV treatment.</p>

<p>PS 3061 is a type of biostimulant, which is derived from activated charcoal. Activated charcoal serves as the source of this biostimulant, providing a unique substrate that interacts with soil and plant roots. Its mode of action involves enhancing nutrient uptake and improving soil microbial activity, thereby facilitating better plant growth and development.</p>

<p>Saquinavir is a HIV protease inhibitor drug that is used with other antiretroviral drugs for the treatment of HIV-1. As this drug prevents HIV protease activity, it prevents the proteolysis of the Gag polyprotein and thus results in non-infectious virus particles.</p>

<p>Anti-viral; HIV integrase inhibitor</p>

<p>Valacyclovir is a guanine nucleoside antiviral drug that is used to treat herpes exacerbations. This drug inhibits DNA polymerase and prevents viral DNA synthesis. Valacyclovir is the L-valine ester of acyclovir.</p>

<p>HIV-1 integrase inhibitor; inhibits DNA strand transfer</p>

<p>Emtricitabine is an antiviral drug that is used to treat chronic viral hepatitis, which is caused by the hepatitis B and C viruses. The drug blocks the activity of reverse transcriptase, which is an enzyme necessary for the replication of viral RNA in the body. Emtricitabine has been shown to be effective against acute hepatitis B virus infection and chronic hepatitis B virus infection with or without cirrhosis. It also has been shown to be effective against chronic hepatitis C virus infection with or without cirrhosis.</p>

<p>Tenofovir diphosphate triethylamine (mixture of diastereomers) is an antiviral compound, which is a synthetic chemical product derived from the parent compound, tenofovir. This formulation includes a mixture of diastereomers to enhance its solubility and bioavailability. The compound primarily functions as a nucleotide reverse transcriptase inhibitor (NRTI). It targets viral reverse transcriptase enzymes, inhibiting DNA synthesis and subsequent viral replication by causing premature chain termination.</p>

<p>Cytarabine is also known as cytosine arabinoside (ara-C) and is a chemotherapy drug that works by inhibiting DNA synthesis. It acts as a nucleoside analogue, which is incorporated into the growing DNA chain during replication. Cytarabine combines a cytosine base with an arabinose sugar (1β-arabinofuranosylcytosine) and is an analog for human deoxycytosine. Cytarabine interferes with DNA synthesis as it is rapidly converted to cytosine arabinoside triphosphate, damaging DNA when cells are in the synthesis phase (S phase). Tumor cells which are highly mitotic and growing rapidly are therefore preferably targeted. Cytarabine also inhibits nucleotide reductase enzymes as well as nuclear polymerases, leading to interruption and inhibition of synthesis, strand breaks and cell death.</p>

<p>Emtricitabine is a nucleoside analog that is an antiviral drug used to treat HIV/AIDS. It is a synthetic nucleoside analog of cytidine, in which the 3' phosphate and 5' hydroxyl groups have been replaced with a fluorine atom and a methoxy group, respectively. Emtricitabine has been shown to inhibit the synthesis of viral DNA by competing for incorporation into the viral DNA strand during the elongation phase of viral replication. Emtricitabine also has anticancer activity, but no other known therapeutic uses.</p>

<p>Galidesivir dihydrochloride is an investigational antiviral drug, which is a synthetic nucleoside analogue with broad-spectrum activity. It is derived from a modified adenosine analog structure, targeting viral RNA-dependent RNA polymerases. Galidesivir functions through the incorporation into viral RNA, leading to premature termination of RNA synthesis, effectively inhibiting viral replication. This mechanism aligns with its utility in combating various RNA viruses.</p>

<p>Etravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) medication used in the treatment of human immunodeficiency virus (HIV) infections. It works by blocking reverse transcriptase, an enzyme essential for replication of the virus, thereby preventing the virus from multiplying and spreading. Etravirine is often used in combination with other antiretroviral drugs to effectively treat HIV/AIDS. It is commonly prescribed for patients with virus strains that are resistant to other NNRTI medications due to mutations that confer resistance- mutations K103N and Y181C. Etravirine is a diarylpyrimidine (DAPY) and has conformational isomerism meaning that it binds reverse transcriptase in an fleible manner, under multiple conformations. The impact of specific point mutations in the virus is therefore lessened.</p>

<p>Applications (S)-Isopropyl 2-(((R)-(((2R,3R,4R,5R)-3-((tert-Butyldimethylsilyl)oxy)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-fluoro-4-methyltetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate is an intermediate in the synthesis of Sofosbuvir (R)-Phosphate (S675615), which is an impurity of PSI-7977 (P839640), a prodrug that is metabolized to the active antiviral agent 2'-deoxy-2'-α-fluoro-β-C-methyluridine-5'-monophosphate and is currently being investigated in phase 3 clinical trials for the treatment of hepatitis C. Studies have profiled PSI-7977 as a nucleotide inhibitor of hepatitis C virus, exerting selective inhibitory effects towards HCV NS5B polymerase.<br>References Lam, A.M.,et al.: Antimicrob. Agents. Chemotherapy., 56, 3359 (2012); Lam, A.M., et al.: J. Virol., 85, 12334 (2011); Sofia, M.J., et al.: J. Medn. Chem., 53, 7202 (2010)<br></p>

<p>Applications 2-Hydroxy-2-methylpropanethioamide is an thioamide compound integrated as an constituent in the synthesis of Ritonavir (R535000) and its derivatives.<br></p>

<p>Applications 1-[2-Deoxy-3,5-O-[1,1,3,3-tetrakis(1-methylethyl)-1,3-disiloxanediyl]-β-D-erythro-pentofuranosyl]-1H-1,2,4-triazole-3-carboxamide is an intermediate in the synthesis of 2’-Deoxyribavirin-5’-triphosphate (D2149940) Triethylamine Salt, a potential new inhibitor for HIV-1 replication.<br>References Vivet-Boudou, V., et al.: Nucleos. Nucleot. Nucl., 26, 743 (2007);<br></p>

<p>Applications (S)-2-(3-((2-(2-Hydroxypropan-2-yl)thiazol-4-yl)methyl)-3-methylureido)-3-methylbutanoic Acid is an intermediate in the synthesis of Ritonavir (R535000) derivatives.<br></p>

<p>Applications 1-[2-O-(Phenoxythioxomethyl)-3,5-O-[1,1,3,3-tetrakis(1-methylethyl)-1,3-disiloxanediyl]-β-D-ribofuranosyl]-1H-1,2,4-triazole-3-carboxamide is an intermediate in the synthesis of 2’-Deoxyribavirin-5’-triphosphate (D2149940) Triethylamine Salt, a potential new inhibitor for HIV-1 replication.<br>References Vivet-Boudou, V., et al.: Nucleos. Nucleot. Nucl., 26, 743 (2007);<br></p>

<p>Applications Used in the synthesis of enantioselective synthesis of carbocyclic ribavirin, its analogs and other antiviral agents.<br>References Kuang, R. et al.; Tetrahedron Lett. 41, 9575 (2000)<br></p>

<p>Applications Intermediate in the preparation of Ribavirin.<br></p>

<p>Applications Intermediate in the preparation of α-Ribavirin.<br></p>

<p>Applications (S)-2-(3-((2-(2-Hydroxypropan-2-yl)thiazol-4-yl)methyl)-3-methylureido)-3-methylbutanoic Acid Methyl Ester is an intermediate in the synthesis of Ritonavir (R535000) derivatives.<br></p>

<p>Applications (S)-(5S,6S,8S)-5,8-Dibenzyl-12,12-dimethyl-3,10-dioxo-1-(thiazol-5-yl)-2,11-dioxa-4,9-diazatridecan-6-yl 2-(3-((2-Isopropylthiazol-4-yl)methyl)-3-methylureido)-3-methylbutanoate is an protected prodrug of Ritonavir (R535000), which is a selective HIV protease inhibitor.<br></p>

<p>Applications (R)-(((1-(6-Amino-9H-purin-9-yl)propan-2-yl)oxy)methyl)phosphonic Acid Methyl Ester Trimethylamine is an intermediate in the synthesis of Tenofovir (T018500), is an acyclic phosphonate nucleotide analogue.<br>References Peng, J., et al.: J. Clin. Pharmacol., 46, 265 (2006), Seminari, E., et al.: J. Antimicrob. Chemother., 60, 831 (2007),<br></p>

<p>Applications A highly reactive thiol-specific spin-label. A specific conformational probe of thiol site structure by virtue of its minimal rotational freedom and distance from the covalent disulfide linkage to the macromolecule under study.<br></p>

<p>Applications T-705RMP TEA Salt is a metabolite of T-705RMP (CAS# 356783-08-9), which is a reagent used for the preparation of pyrazine-ribofuranose derivatives as antiviral agents that are useful in the treatment of viral infections. T-705 (Favipiravir) [F103350] gets converted to T-705RMP by host cells, but T-705RMP has little inhibitory effect on the replication of the host cells based on biological studies.<br>References Zhong, B., et al.: Faming Zhuanli Shenqing, 2014:924257 (2014); Yousuke, F., et al.: Antimicrob Agent Chemother., 49, 981 (2005)<br></p>

<p>Tenofovir diphosphate is an antiviral compound, which is a key active metabolite derived from the prodrugs tenofovir disoproxil fumarate and tenofovir alafenamide, both originating from chemical synthesis. Its mode of action involves inhibiting the activity of HIV-1 reverse transcriptase by competing with the natural substrate, deoxyadenosine 5’-triphosphate, and causing chain termination after incorporation into viral DNA. This mechanism effectively prevents the replication of retroviral DNA, thus halting the progression of the infection.</p>

<p>Foscarnet sodium is a pyrophosphate analog antiviral agent with action on viral DNA polymerase and is used for treating cytomegalovirus and herpes simplex virus infections.</p>

<p>Acetyl daclatasvir is a direct-acting antiviral agent, which is chemically derived from a series of small-molecule inhibitors. The source of this compound lies in rational drug design, focusing on targeting specific viral proteins involved in the replication of hepatitis C virus (HCV). Its mode of action involves inhibiting the NS5A protein, a non-structural protein essential for HCV RNA replication and virion assembly. By binding to NS5A, acetyl daclatasvir disrupts the replication complex, effectively halting the virus's ability to multiply within the host cells.</p>

<p>Vidarabine monohydrate is an antiviral agent with action on viral DNA polymerase to inhibit replication and is used for treating herpes simplex virus infections and varicella-zoster virus infections.</p>

<p>HCV-IN-30 is an HCV NS5A replication complex inhibitor (IC50s: 901 and 102 nM for genotypes 1a and 1b replicons).</p>

<p>Applications Stavudine-alpha,alpha,alpha,6-d4 (CAS# 1219803-67-4) is a useful isotopically labeled research compound.<br></p>

<p>Applications 2'-Fluoro-2'-deoxyuridine-5,6-d2 (CAS# 362049-50-1) is a useful isotopically labeled research compound.<br></p>

<p>Applications An intermediate in the synthesis of Ritonavir.<br>References Sham, H., et al.: Bioorg. Med. Chem. Lett., 12, 3101 (2002),<br></p>

<p>Applications 3,4-Difluoroaniline-2,6-d2 (CAS# 1061566-62-8) can be used in its derivative form as an antiviral agent for Hepatitis B.<br>References Qiu, Y.L., et.al., U.S. Pat. Appl. Publ., 187,(2019);<br></p>

<p>Impurity Atazanavir Impurity B<br>Applications An intermediate for the preparation of antiviral protease inhibitors. Atazanavir Impurity B<br>References Fassler, A., et al.: J. Med. Chem., 39, 3203 (1996), Bold, G., et al.: J. Med. Chem., 41, 3387 (1998).<br></p>

<p>Impurity Atazanavir Impurity (Pyridinyl Benzaldehyde)<br>Applications Reactive metabolite of atazanavir. Atazanavir Impurity; Pyridinyl Benzaldehyde impurity<br>References F. Li et al., Drug Metabolism and Disposition 39, 294 (2011)<br></p>

<p>Applications 5,6,7,8-Tetrahydro-1-naphthalenol was used as a reagent in the synthesis of phosphonamidate and phosphonodiamidate prodrugs of adefovir and tenofovir which are used in the treatment of HIV infections. Also used in the synthesis of tetrahydronaphthalene-1-ol derivatives which were found to be promising potent antitumor agents.<br>References Pertusati, F., et al.: Eur. J. Med. Chem., 78, 259 (2014); Dong, Y., et al.: Bioorg. Med. Chem. Lett., 19, 6289 (2009);<br></p>

<p>Applications Darunavir intermediate.<br>References Ghosh, A., et al.: J. Med. Chem., 39, 3278 (1996), Ghosh, A., et al.: Bioorg. Med. Chem. Lett., 1998, 8, 687 (1998), Richman, D., et al.: Nature, 410, 995 (2001), Koh, Y., et al.: Antimicrob. Agents Chemother., 47, 3123 (2003),<br></p>

<p>Stability Hygroscopic<br>Applications (2'R)​-2'-​Deoxy-​2'-​fluoro-​2'-​methyl-uridine 5'-​Triphosphate Tetrasodium Salt is an impurity of Sofosbuvir (P839640) which is a prodrug that is metabolized to the active antiviral agent 2'-deoxy-2'-α-fluoro-β-C-methyluridine-5'-monophosphate.<br>References Lam, A.M.,et al.: Antimicrob. Agents. Chemotherapy., 56, 3359 (2012); Lam, A.M., et al.: J. Virol., 85, 12334 (2011); Sofia, M.J., et al.: J. Medn. Chem., 53, 7202 (2010);<br></p>

<p>Applications R 77975 is used to modulate lipophilicity in human rhinovirus capsid binders. It also is used in order to identify potential ativiral agents.<br>References Morley, A. et al.: Bioorg. Med. Chem. Lett., 21, 6031 (2011); Tomkinson, N. et al.: Bioorg. Med. Chem. Lett., 22, 7494 (2012);<br></p>

<p>Impurity Nelfinavir Sulphone Impurity<br>Applications Nelfinavir Sulfone is an impurity of Nelfinavir Mesylate (N389750). It is a COVID19-related research product.<br>References Aymard, G., et al.: J. Chromatogr. B, 744, 227 (2000), Jing, Q., et al.: J. Pharm. Biomed. Anal., 41, 1065 (2006),<br></p>

<p>Impurity Ribavirin EP Impurity C<br>Applications 1,2,4-Triazole-3-carboxylic Acid (Ribavirin EP Impurity C) is a major metabolite of the antiviral agent Ribavirin (R414475).<br>References Miller, J.P. et al.: Ann. N.Y. Acad. Sci., 284, 211 (1977); Catlin, D. et al.: Ribavirin: Broad Spec. Antivir. Ag., 83 (1980); Lin, C.C. et al.: Antimicrob. Ag. Chemother., 50, 2368 (2006);<br></p>

<p>Applications Darunavir intermediate.<br>References Ghosh, A., et al.: J. Med. Chem., 39, 3278 (1996), Ghosh, A., et al.: Bioorg. Med. Chem. Lett., 1998, 8, 687 (1998), Richman, D., et al.: Nature, 410, 995 (2001), Koh, Y., et al.: Antimicrob. Agents Chemother., 47, 3123 (2003),<br></p>

<p>Applications Levovirin is a monocyclic L-nucleosides with type 1 cytokine-inducing activity. Levovirin is the L-enantiomer of Ribavirin (R414475) with similar immunomodulatory activity but does not have direct antiviral activity or hemolytic anemia.<br>References Ramasamy, K.S. et al.: J. Med. Chem., 43, 1019 (2000); Fang, C. et al.: J. Appl. Toxicol., 23, 453 (2003):<br></p>

<p>Applications An intermediate used in the preparation of Zanamivir derivatives.<br>References Andrews, D., et al.: Eur. J. Med. Chem., 34, 563 (1999), Altamore, T., et al.: Bioorg. Med. Chem., 14, 1126 (2006),<br></p>

<p>RNA polymerase (RdRp) inhibitor</p>

<p>Vicriviroc malate is a CCR5 antagonist with action on blocking HIV entry into cells by targeting the CCR5 receptor and is used for research on HIV treatment.</p>

<p>Alamifovir is an antiviral agent, which is synthetically derived. The mode of action of Alamifovir involves the inhibition of viral replication within host cells by targeting specific viral enzymes crucial for the replication process. This interference with the viral life cycle diminishes the ability of the virus to propagate and spread within the host organism.</p>