 Chemical Structure.png)
Physicochemical Properties
| Molecular Formula | C13H19N3O7 |
| Molecular Weight | 329.3059 |
| Exact Mass | 329.12 |
| Elemental Analysis | C, 47.42; H, 5.82; N, 12.76; O, 34.01 |
| CAS # | 2492423-29-5 |
| Related CAS # | Molnupiravir-d7 |
| PubChem CID | 145996610 |
| Appearance | White to off-white solid powder |
| LogP | -0.8 |
| Hydrogen Bond Donor Count | 4 |
| Hydrogen Bond Acceptor Count | 7 |
| Rotatable Bond Count | 6 |
| Heavy Atom Count | 23 |
| Complexity | 534 |
| Defined Atom Stereocenter Count | 4 |
| SMILES | O1[C@]([H])([C@@]([H])([C@@]([H])([C@@]1([H])C([H])([H])OC(C([H])(C([H])([H])[H])C([H])([H])[H])=O)O[H])O[H])N1C(N=C(C([H])=C1[H])N([H])O[H])=O |
| InChi Key | O[C@@H]([C@H]([C@H](N1C(N/C(C=C1)=N/O)=O)O2)O)[C@H]2COC(C(C)C)=O |
| InChi Code | HTNPEHXGEKVIHG-QCNRFFRDSA-N |
| Chemical Name | InChI=1S/C13H19N3O7/c1-6(2)12(19)22-5-7-9(17)10(18)11(23-7)16-4-3-8(15-21)14-13(16)20/h3-4,6-7,9-11,17-18,21H,5H2,1-2H3,(H,14,15,20)/t7-,9-,10-,11-/m1/s1 |
| Synonyms | MK 4482; EIDD-2801; EIDD 2801; Molnupiravir; MK-4482; MK4482; EIDD2801; prodrug-EIDD-1931; prodrug-EIDD 1931; prodrug-EIDD1931. |
| HS Tariff Code | 2934.99.9001 |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets | Broad-spectrum antiviral |
| ln Vitro | The RNA-dependent RNA polymerase of the severe acute respiratory syndrome coronavirus 2 is an important target in current drug development efforts for the treatment of coronavirus disease 2019. Molnupiravir is a broad-spectrum antiviral that is an orally bioavailable prodrug of the nucleoside analogue β-D-N4-hydroxycytidine (NHC). Molnupiravir or NHC can increase G to A and C to U transition mutations in replicating coronaviruses. These increases in mutation frequencies can be linked to increases in antiviral effects; however, biochemical data of molnupiravir-induced mutagenesis have not been reported. Here we studied the effects of the active compound NHC 5’-triphosphate (NHC-TP) against the purified severe acute respiratory syndrome coronavirus 2 RNA-dependent RNA polymerase complex. The efficiency of incorporation of natural nucleotides over the efficiency of incorporation of NHC-TP into model RNA substrates followed the order GTP (12,841) > ATP (424) > UTP (171) > CTP (30), indicating that NHC-TP competes predominantly with CTP for incorporation. No significant inhibition of RNA synthesis was noted as a result of the incorporated monophosphate in the RNA primer strand. When embedded in the template strand, NHC-monophosphate supported the formation of both NHC:G and NHC:A base pairs with similar efficiencies. The extension of the NHC:G product was modestly inhibited, but higher nucleotide concentrations could overcome this blockage. In contrast, the NHC:A base pair led to the observed G to A (G:NHC:A) or C to U (C:G:NHC:A:U) mutations. Together, these biochemical data support a mechanism of action of molnupiravir that is primarily based on RNA mutagenesis mediated via the template strand [3]. |
| ln Vivo | Molnupiravir has strong antiviral properties and can stop SARS-CoV multiplication and illness [1]. It is administered orally every 12 hours for three days at a dose of 50–500 mg/kg. The duration of fever and viral load are dramatically reduced by molnupiravir (7 mg/kg), when administered orally twice daily for 3.5 days [2]. |
| Enzyme Assay | NTP incorporation and the effect of primer- or template-embedded NHC-MP on viral RNA synthesis[3] NTP incorporation by SARS-CoV-2 RdRp and data acquisition and quantification were done as reported by us. Enzyme concentration was 100 or 200 nM for single and multiple nucleotide incorporation assays, respectively. RNA synthesis incubation time was 10 min. Data from single nucleotide incorporation assays were used to determine the preference for the natural nucleotide over NHC-TP. The selectivity value is calculated as a ratio of the incorporation efficiencies of the natural nucleotide over the nucleotide analogue. The efficiency of nucleotide incorporation is determined by the ratio of Michaelis–Menten constants Vmax over Km. The substrate for nucleotide incorporation is a 5-nt primer generated by incorporation of [α-32P]NTP into a 4-nt primer. Formation of the 5-nt primer is maximal at a given time point; however, its precise concentration is unknown. Hence, the product generated in the reaction is measured by quantifying the signal corresponding to the 6-nt primer product and dividing it to the total signal in the reaction (5-nt primer and 6-nt primer). This defines the product fraction. The product fraction is commonly multiplied by the total substrate concentration in order to determine the molar units of the Vmax, which is here not possible as explained above. Therefore, the unit of Vmax is reported as product fraction over time. The selectivity value is unitless as it is the ratio of two Vmax/Km measurements with the same units. RNA templates with embedded NHC-MP were produced as described by us. NHC-related protocol modifications are explained in Fig. S1. |
| Cell Assay | Madin-Darby canine kidney (MDCK) cells (ATCC CCL-34) were grown at 37°C and 5% CO2 in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 7.5% fetal bovine serum (FBS). Normal primary human bronchial tracheal epithelial cells (HBTECs) from a 30-year old healthy female donor were grown in BronchiaLife cell culture medium. These cells were obtained by the vendor under informed consent and adheres to the Declaration of Helsinki, The Human Tissue Act (UK), CFR Title 21, and HIPAA regulations. All regulatory approval lies with the vendor. Immortalized cell lines used in this study were routinely checked for microbial contamination (in approximately 6-month intervals). HBTECs were tested for microbial contamination on July 25, 2017 by LifeLine Cell Technology. Only HBTECs with a passage number 1-4 were used for this study [2]. |
| Animal Protocol |
Animal/Disease Models: C57BL/6 mice (intranasal infection with SARS-CoV)[1] Doses: 50, 150, 500 mg/kg Route of Administration: Oral; every 12 hrs (hours) for 3 days Experimental Results: Body weight loss is Dramatically diminished or prevented. Animal/Disease Models: Ca/09-infected female ferrets[1] Doses: 7 mg/kg Route of Administration: Oral; twice (two times) daily for 3.5 days Experimental Results: Shed virus load and duration of fever were Dramatically diminished. |
| ADME/Pharmacokinetics |
Absorption, Distribution and Excretion After an 800 mg oral dose of molnupiravir every 12 hours, the active compound (N4-hydroxycytidine) reaches a Cmax of 2970 ng/mL, with a Tmax of 1.5 hours, and an AUC0-12h of 8360 h\*ng/mL. ≤3% of an oral molnupiravir dose is eliminated in the urine as the active metabolite N4-hydroxycytidine. Metabolism / Metabolites Molnupiravir is hydrolyzed to [N4-hydroxycytidine], which distributes into tissues. Once inside cells, N4-hydroxycytidine is phosphorylated to the 5'-triphosphate form. Biological Half-Life The half life of the active metabolite, N4-hydroxycytidine, is 3.3 hours. |
| Toxicity/Toxicokinetics |
Hepatotoxicity In preregistration clinical trials, serum aminotransferase elevations were uncommon and mild, and were no more frequent with molnupiravir than with placebo. Furthermore, among more than 900 patients treated with molnupiravir (800 mg twice daily) for 5 days in prelicensure studies, there were no reported episodes of clinically apparent liver injury. Confounding the issue is that serum aminotransferase elevations are common during symptomatic SARS-CoV-2 infection, present in up to 70% of patients and are more frequent in patients with severe disease and in those with the known risk factors for COVID-19 severity such as male sex, older age, higher body mass index and diabetes. Thus, molnupiravir has not been shown to cause liver injury, but the total clinical experience with its use is limited. Likelihood score: E (unlikely cause of clinically apparent liver injury). Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation No information is available on the use of molnupiravir during breastfeeding. Breastfeeding is not recommended during treatment and for 4 days after the last dose of molnupiravir. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date. ◈ What is molnupiravir? Molnupiravir is an antiviral medication that has been given emergency permission by the U.S. Food and Drug Administration (FDA) to treat mild to moderate COVID-19 in certain patients. Molnupiravir must be started within 5 days of having symptoms of COVID-19 in order to be effective. A brand name for molnupiravir is Lagevrio®.The FDA emergency use guidelines for molnupiravir recommend people who are pregnant not use this medication unless there are no other treatment options and treatment is clearly needed. This is because there is not enough information available on the use of molnupiravir to know if/how it could affect a pregnancy. However, the benefit of using molnupiravir may outweigh possible risks. Your healthcare provider can talk with you about using molnupiravir and what treatment is best for you. For more information about COVID-19, please the see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/covid-19/. ◈ I am taking molnupiravir, but I would like to get pregnant after taking it. How long does the drug stay in my body? People eliminate medication at different rates. In non-pregnant adults, it takes up to 1 day, on average, for most of the molnupiravir to be gone from the body. The FDA emergency use guidelines recommend that females avoid trying to get pregnant while they are taking molnupiravir and for 4 days after the last dose. ◈ I take molnupiravir. Can it make it harder for me to get pregnant? It is not known if molnupiravir can make it harder to get pregnant. The FDA emergency use guidelines recommend that females who can get pregnant use effective contraception correctly and consistently while they are taking molnupiravir and for 4 days after the last dose. ◈ Does taking molnupiravir increase the chance of miscarriage? Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done in humans to see if molnupiravir can increase the chance of miscarriage. ◈ Does taking molnupiravir increase the chance of birth defects? Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Studies have not been done in humans to see if molnupiravir can increase the chance of birth defects above the background risk. ◈ Does taking molnupiravir in pregnancy increase the chance of other pregnancy-related problems? Studies have not been done in humans to see if molnupiravir can increase the chance of pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). Having COVID-19 during pregnancy can increase the chance of preterm delivery, stillbirth, and other pregnancy complications. ◈ Does taking molnupiravir in pregnancy affect future behavior or learning for the child? Studies have not been done to see if molnupiravir can cause behavior or learning issues for the child. ◈ Breastfeeding while taking molnupiravir: The FDA emergency use guidelines for molnupiravir recommend that people who are breastfeeding not use this medication unless there are no other treatment options and treatment is clearly needed. But the benefit of using molnupiravir along with the benefits of breastfeeding your baby may outweigh possible risks. People who are breastfeeding can consider pumping and discarding breast milk during treatment with molnupiravir and for 4 days after the last dose. Your healthcare providers can talk with you about using molnupiravir and what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions. ◈ If a male takes molnupiravir, could it affect fertility or increase the chance of birth defects? Studies have not been done to see if molnupiravir could affect male fertility (ability to get partner pregnant) or increase the chance of birth defects above the background risk. The FDA emergency use guidelines recommend that males use a reliable method of contraception correctly and consistently during treatment and for at least 3 months after the last dose of molnupiravir. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/. Protein Binding Molnupiravir and the active metabolite, N4-hydroxycytidine, are not protein bound in plasma. |
| References |
[1]. Sheahan TP, et al. An orally bioavailable broad-spectrum antiviral inhibits SARS-CoV-2 in human airway epithelial cell cultures and multiple coronaviruses in mice. Sci Transl Med. 2020 Apr 6. pii: eabb5883. [2]. Toots M, et al. Characterization of orally efficacious influenza drug with high resistance barrier in ferrets and human airway epithelia. Sci Transl Med. 2019 Oct 23;11(515). pii: eaax5866. [3]. Molnupiravir promotes SARS-CoV-2 mutagenesis via the RNA template. Biol Chem. 2021 Jul; 297(1): 100770. |
| Additional Infomation |
Molnupiravir is a nucleoside analogue that is N(4)-hydroxycytidine in which the 5'-hydroxy group is replaced by a (2-methylpropanoyl)oxy group. It is the prodrug of the active antiviral ribonucleoside analog N(4)-hydroxycytidine (EIDD-1931), has activity against a number of RNA viruses including SARS-CoV-2, MERS-CoV, and seasonal and pandemic influenza viruses. It is currently in phase III trials for the treatment of patients with COVID-19. It has a role as a prodrug, an anticoronaviral agent and an antiviral drug. It is a nucleoside analogue, an isopropyl ester and a ketoxime. It is functionally related to a N(4)-hydroxycytidine. Molnupiravir (EIDD-2801, MK-4482) is the isopropylester prodrug of [N4-hydroxycytidine]. With improved oral bioavailability in non-human primates, it is hydrolyzed in vivo, and distributes into tissues where it becomes the active 5’-triphosphate form. The active drug incorporates into the genome of RNA viruses, leading to an accumulation of mutations known as viral error catastrophe. Recent studies have shown molnupiravir inhibits replication of human and bat coronaviruses, including SARS-CoV-2, in mice and human airway epithelial cells. A [remdesivir] resistant mutant mouse hepatitis virus has also been shown to have increased sensitivity to N4-hydroxycytidine. Molnupiravir was granted approval by the UK's Medicines and Health products Regulatory Agency (MHRA) on 4 November 2021 to prevent severe outcomes such as hospitalization and death due to COVID-19 in adults. Molnupiravir was also granted emergency use authorization by the FDA on December 23, 2021; however, it is not yet fully approved. Molnupiravir is a ribonucleoside analogue and antiviral agent that is used in the therapy the severe acute respiratory syndrome (SARS) coronavirus 2 (CoV-2) infection, the cause of the novel coronavirus disease, 2019 (COVID-19). Molnupiravir therapy is given orally for 5 days early in the course of SARS-CoV-2 infection and has not been linked to serum aminotransferase elevations or to clinically apparent liver injury. Molnupiravir is an orally bioavailable prodrug of EIDD-1931, the synthetic ribonucleoside derivative N4-hydroxycytidine and ribonucleoside analog, with potential antiviral activity against a variety of RNA viruses. Upon oral administration, molnupiravir, being a prodrug, is metabolized into its active form EIDD-1931 and converted into its triphosphate (TP) form. The TP form of EIDD-1931 is incorporated into RNA and inhibits the action of viral RNA-dependent RNA polymerase. This results in the termination of RNA transcription and decreases viral RNA production, and viral RNA replication. Drug Indication [N4-hydroxycytidine] and its prodrug molnupiravir are being studied for its activity against a number of viral infections including influenza, MERS-CoV, and SARS-CoV-2. Molnupiravir is approved in the UK for reducing the risk of hospitalization and death in mild to moderate COVID-19 cases for patients at increased risk of severe disease (eg. with obesity, diabetes mellitus, heart disease, or are over 60 years old). In the US, molnupiravir is authorized for emergency use for the treatment of high-risk adults With mild to moderate COVID-19. Prevention of Coronavirus disease 2019 (COVID-19) Treatment of Coronavirus disease 2019 (COVID-19) Mechanism of Action Molnupiravir is hydrolyzed _in vivo_ to N4-hydroxycytidine, which is phosphorylated in tissue to the active 5’-triphosphate form, and incorporated into the genome of new virions, resulting in the accumulation of inactivating mutations, known as viral error catastrophe. A [remdesivir] resistant mutant mouse hepatitis virus has also been shown to have increased sensitivity to N4-hydroxycytidine. |
Solubility Data
| Solubility (In Vitro) | DMSO : 50 mg/mL (151.83 mM) |
| Solubility (In Vivo) |
Solubility in Formulation 1: 12.05 mg/mL (36.59 mM) in 10% PEG400 2.5% Ethoxylated hydrogenated castor oil 87.5% water (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.59 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (7.59 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 4: ≥ 2.5 mg/mL (7.59 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL corn oil and mix evenly. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 3.0367 mL | 15.1833 mL | 30.3665 mL | |
| 5 mM | 0.6073 mL | 3.0367 mL | 6.0733 mL | |
| 10 mM | 0.3037 mL | 1.5183 mL | 3.0367 mL |