WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 555278

CAS#: 55321-99-8

Description: T-1105 is a broad-spectrum antiviral inhibitor that demonstrates good activity for various RNA viruses, including influenza virus, arenaviruses, bunyaviruses, West Nile virus (WNV), yellow fever virus (YFV), FMDV, and ZIKV.

Chemical Structure

CAS# 55321-99-8

Theoretical Analysis

MedKoo Cat#: 555278
Name: T-1105
CAS#: 55321-99-8
Chemical Formula: C5H5N3O2
Exact Mass: 139.0382
Molecular Weight: 139.114
Elemental Analysis: C, 43.17; H, 3.62; N, 30.21; O, 23.00

Price and Availability

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200.0mg USD 90.0 Same day
500.0mg USD 150.0 Same day
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2.0g USD 350.0 Same day
5.0g USD 550.0 Same day
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Synonym: T-1105; T 1105; T1105.

IUPAC/Chemical Name: 3-oxo-3,4-dihydropyrazine-2-carboxamide


InChi Code: InChI=1S/C5H5N3O2/c6-4(9)3-5(10)8-2-1-7-3/h1-2H,(H2,6,9)(H,8,10)


Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO

Shelf Life: >3 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Certificate of Analysis:

Safety Data Sheet (SDS):

Preparing Stock Solutions

The following data is based on the product molecular weight 139.114 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Huchting J, Vanderlinden E, Winkler M, Nasser H, Naesens L, Meier C. Prodrugs of the Phosphoribosylated Forms of Hydroxypyrazinecarboxamide Pseudobase T-705 and its De-Fluoro-Analogue T-1105 as Potent Influenza Virus Inhibitors. J Med Chem. 2018 Jun 15. doi: 10.1021/acs.jmedchem.8b00617. [Epub ahead of print] PubMed PMID: 29906392.

2: Qiu L, Patterson SE, Bonnac LF, Geraghty RJ. Nucleobases and corresponding nucleosides display potent antiviral activities against dengue virus possibly through viral lethal mutagenesis. PLoS Negl Trop Dis. 2018 Apr 19;12(4):e0006421. doi: 10.1371/journal.pntd.0006421. eCollection 2018 Apr. PubMed PMID: 29672522; PubMed Central PMCID: PMC5929572.

3: Cai L, Sun Y, Song Y, Xu L, Bei Z, Zhang D, Dou Y, Wang H. Viral polymerase inhibitors T-705 and T-1105 are potential inhibitors of Zika virus replication. Arch Virol. 2017 Sep;162(9):2847-2853. doi: 10.1007/s00705-017-3436-8. Epub 2017 Jun 8. PubMed PMID: 28597088; PubMed Central PMCID: PMC5563514.

4: de Avila AI, Moreno E, Perales C, Domingo E. Favipiravir can evoke lethal mutagenesis and extinction of foot-and-mouth disease virus. Virus Res. 2017 Apr 2;233:105-112. doi: 10.1016/j.virusres.2017.03.014. Epub 2017 Mar 18. PubMed PMID: 28322918.

5: De Vleeschauwer AR, Lefebvre DJ, Willems T, Paul G, Billiet A, Murao LE, Neyts J, Goris N, De Clercq K. A Refined Guinea Pig Model of Foot-and-Mouth Disease Virus Infection for Assessing the Efficacy of Antiviral Compounds. Transbound Emerg Dis. 2016 Apr;63(2):e205-12. doi: 10.1111/tbed.12255. Epub 2014 Aug 28. PubMed PMID: 25164494.

6: Naesens L, Guddat LW, Keough DT, van Kuilenburg AB, Meijer J, Vande Voorde J, Balzarini J. Role of human hypoxanthine guanine phosphoribosyltransferase in activation of the antiviral agent T-705 (favipiravir). Mol Pharmacol. 2013 Oct;84(4):615-29. doi: 10.1124/mol.113.087247. Epub 2013 Aug 1. PubMed PMID: 23907213.

7: Furuta Y, Takahashi K, Shiraki K, Sakamoto K, Smee DF, Barnard DL, Gowen BB, Julander JG, Morrey JD. T-705 (favipiravir) and related compounds: Novel broad-spectrum inhibitors of RNA viral infections. Antiviral Res. 2009 Jun;82(3):95-102. doi: 10.1016/j.antiviral.2009.02.198. Epub 2009 Mar 6. Review. PubMed PMID: 19428599.


200.0mg / USD 90.0