Flucytosine (CHEM002344)

Record Information
Version1.0
Creation Date2009-07-21 20:28:21 UTC
Update Date2026-05-14 16:57:49 UTC
Accession NumberCHEM002344
Identification
Common NameFlucytosine
ClassSmall Molecule
Description
Flucytosine is only found in individuals that have used or taken this drug. It is a fluorinated cytosine analog that is used as an antifungal agent. [PubChem]Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase.
Contaminant Sources
  • HMDB Contaminants - Urine
  • STOFF IDENT Compounds
  • T3DB toxins
  • ToxCast & Tox21 Chemicals
Contaminant Type
  • Amine
  • Antifungal Agent
  • Antimetabolite
  • Drug
  • Metabolite
  • Organic Compound
  • Organofluoride
  • Synthetic Compound
Chemical Structure
MOLSDF3D SDFPDBSMILESInChI View 3D Structure
Synonyms
ValueSource
5-FCChEBI
5-FluorocystosineChEBI
5-FluorocytosineChEBI
AncobonChEBI
AncotilChEBI
FlucytosinaChEBI
FlucytosinumChEBI
5-FluorocytosinHMDB
5-FlurocytosineHMDB
FlucytosinHMDB
FluocytosineHMDB
FluorcytosineHMDB
Dermatech brand OF flucytosineHMDB
Roche brand OF flucytosineHMDB
AlcobonHMDB
CSP Brand OF flucytosineHMDB
ICN pharmaceuticals brand OF flucytosineHMDB
Allphar brand OF flucytosineHMDB
Chemical FormulaC4H4FN3O
Average Molecular Mass129.093 g/mol
Monoisotopic Mass129.034 g/mol
CAS Registry Number2022-85-7
IUPAC Name6-amino-5-fluoro-1,2-dihydropyrimidin-2-one
Traditional Nameflucytosine
SMILESNC1=C(F)C=NC(=O)N1
InChI IdentifierInChI=1S/C4H4FN3O/c5-2-1-7-4(9)8-3(2)6/h1H,(H3,6,7,8,9)
InChI KeyXRECTZIEBJDKEO-UHFFFAOYSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as halopyrimidines. These are aromatic compounds containing a halogen atom linked to a pyrimidine ring. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassDiazines
Sub ClassPyrimidines and pyrimidine derivatives
Direct ParentHalopyrimidines
Alternative Parents
Substituents
  • Aminopyrimidine
  • Halopyrimidine
  • Pyrimidone
  • Aryl fluoride
  • Aryl halide
  • Hydropyrimidine
  • Heteroaromatic compound
  • Azacycle
  • Amine
  • Primary amine
  • Organooxygen compound
  • Organonitrogen compound
  • Organofluoride
  • Organohalogen compound
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Organic oxygen compound
  • Organic nitrogen compound
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
Applications
Biological Roles
Chemical RolesNot Available
Physical Properties
StateSolid
AppearanceWhite powder.
Experimental Properties
PropertyValue
Melting Point296°C
Boiling PointNot Available
Solubility1.5E+004 mg/L (at 25°C)
Predicted Properties
PropertyValueSource
Water Solubility1.92 g/LALOGPS
logP-0.24ALOGPS
logP-0.95ChemAxon
logS-1.8ALOGPS
pKa (Strongest Acidic)8.16ChemAxon
pKa (Strongest Basic)1.06ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area67.48 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity38.22 m³·mol⁻¹ChemAxon
Polarizability9.97 ųChemAxon
Number of Rings1ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectra
Toxicity Profile
Route of ExposureRapidly and virtually completely absorbed following oral administration. Bioavailability 78% to 89%.
Mechanism of ToxicityAlthough the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine enters the fungal cell via cytosine permease; thus, flucytosine is metabolized to 5-fluorouracil within fungal organisms. The 5-fluorouracil is extensively incorporated into fungal RNA and inhibits synthesis of both DNA and RNA. The result is unbalanced growth and death of the fungal organism. It also appears to be an inhibitor of fungal thymidylate synthase.
MetabolismFlucytosine is deaminated, possibly by gut bacteria or by the fungal targets, to 5-fluorouracil, the active metabolite. Route of Elimination: Flucytosine is excreted via the kidneys by means of glomerular filtration without significant tubular reabsorption. A small portion of the dose is excreted in the feces. Half Life: 2.4 to 4.8 hours.
Toxicity ValuesLD50: 15 gm/kg (Oral, Rat) (1)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesFor the treatment (in combination with amphotericin B) of serious infections caused by susceptible strains of Candida (septicemia, endocarditis and urinary system infections) and/or Cryptococcus (meningitis and pulmonary infections).
Minimum Risk LevelNot Available
Health EffectsNot Available
SymptomsNot Available
TreatmentIn the management of overdosage, prompt gastric lavage or the use of an emetic is recommended. Adequate fluid intake should be maintained, by the intravenous route if necessary, since Ancobon is excreted unchanged via the renal tract. The hematologic parameters should be monitored frequently; liver and kidney function should be carefully monitored. Should any abnormalities appear in any of these parameters, appropriate therapeutic measures should be instituted. Since hemodialysis has been shown to rapidly reduce serum concentrations in anuric patients, this method may be considered in the management of overdosage. (5)
Concentrations
Not Available
External Links
DrugBank IDDB01099
HMDB IDHMDB0015231
FooDB IDNot Available
Phenol Explorer IDNot Available
KNApSAcK IDNot Available
BiGG IDNot Available
BioCyc IDNot Available
METLIN IDNot Available
PDB IDNot Available
Wikipedia LinkFlucytosine
Chemspider ID3249
ChEBI ID5100
PubChem Compound ID3366
Kegg Compound IDNot Available
YMDB IDNot Available
ECMDB IDNot Available
References
Synthesis Reference

Bernd Baasner, Erich Klauke, “Process for the preparation of 5-fluorocytosine.” U.S. Patent US4703121, issued September, 1961.

MSDSLink
General References
1. Bertout S, Dunyach C, Drakulovski P, Reynes J, Mallie M: Comparison of the Sensititre YeastOne(R) dilution method with the Clinical Laboratory Standards Institute (CLSI) M27-A3 microbroth dilution reference method for determining MIC of eight antifungal agents on 102 yeast strains. Pathol Biol (Paris). 2011 Feb;59(1):48-51. doi: 10.1016/j.patbio.2010.07.020. Epub 2010 Sep 16.
2. Kaouech E, Kallel K, Belhadj S, Anane S, Ben Chaabane T, Ben Fadhl K, Khedher A, Meddeb B, Ben Lakhal S, Chaker E: [Twenty-two cases of neuromeningeal cryptococcosis in Tunisia]. Med Mal Infect. 2009 Dec;39(12):914-9. doi: 10.1016/j.medmal.2009.02.004. Epub 2009 Apr 8.
3. Park BJ, Park JC, Taguchi H, Fukushima K, Hyon SH, Takatori K: Antifungal susceptibility of epigallocatechin 3-O-gallate (EGCg) on clinical isolates of pathogenic yeasts. Biochem Biophys Res Commun. 2006 Aug 25;347(2):401-5. Epub 2006 Jun 15.
4. https://www.ncbi.nlm.nih.gov/pubmed/?term=11519290
5. https://www.ncbi.nlm.nih.gov/pubmed/?term=14871609
6. https://www.ncbi.nlm.nih.gov/pubmed/?term=18731030
7. https://www.ncbi.nlm.nih.gov/pubmed/?term=23576540
8. https://www.ncbi.nlm.nih.gov/pubmed/?term=25649231
9. https://www.ncbi.nlm.nih.gov/pubmed/?term=26201447
10. https://www.ncbi.nlm.nih.gov/pubmed/?term=28166217