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Record Information
StatusExpected but not Quantified
Creation Date2012-09-06 15:16:51 UTC
Update Date2020-02-26 21:41:13 UTC
Secondary Accession Numbers
  • HMDB15231
Metabolite Identification
Common NameFlucytosine
DescriptionFlucytosine 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.
Dermatech brand OF flucytosineHMDB
Roche brand OF flucytosineHMDB
CSP Brand OF flucytosineHMDB
ICN pharmaceuticals brand OF flucytosineHMDB
Allphar brand OF flucytosineHMDB
Chemical FormulaC4H4FN3O
Average Molecular Weight129.0925
Monoisotopic Molecular Weight129.03383997
IUPAC Name6-amino-5-fluoro-1,2-dihydropyrimidin-2-one
Traditional Nameflucytosine
CAS Registry Number2022-85-7
InChI Identifier
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
Sub ClassPyrimidines and pyrimidine derivatives
Direct ParentHalopyrimidines
Alternative Parents
  • 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

Route of exposure:

Biological location:


Industrial application:

Physical Properties
Experimental Properties
Melting Point296 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility1.92 g/LNot Available
LogP-1.1Not Available
Predicted Properties
Water Solubility1.92 g/LALOGPS
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
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-004i-5900000000-62cd06162d248f459f77Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-002r-9400000000-acd1b588a4052f6fc2ddSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-002r-9400000000-a4e7dd3c4c886861c0eaSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-000i-9200000000-b3fb9cad9c2b375b08c6Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-000i-9100000000-11fb61e55faa71878d87Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-000i-9000000000-13935b6ab4a3d8adaa08Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , negativesplash10-000i-9000000000-cd981efe159dd44555f4Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-001i-0900000000-a228aa7f5ecaf516455fSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-001i-0900000000-ec5b7f7d9f3c75649dc2Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-03e9-0900000000-15df2a7b685c4dd4ca17Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-001i-0900000000-7110f8accb80c700a2a5Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-001i-0900000000-89290e0501d587938afbSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-001i-0900000000-7248b6df062077397b61Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-001i-1900000000-df83e87e1bcbc8311be6Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-01q9-3900000000-42649a5ceee8a4619fc3Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QFT , positivesplash10-08gr-9800000000-8cb7a586d34dd7913561Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-001i-0900000000-3daf46ab201d0847e716Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-001i-4900000000-08676c044da012e58509Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0007-9000000000-fc78e7fb18ada3e97d98Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-004i-2900000000-d0b2503a7f5865ac1efdSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-00nu-9100000000-ee11917ba44963a8210bSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0006-9000000000-e5c5889e9b5cd0c8cae9Spectrum
Biological Properties
Cellular Locations
  • Cytoplasm
Biospecimen Locations
  • Blood
  • Urine
Tissue LocationsNot Available
Normal Concentrations
BloodExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableTaking drug identified by DrugBank entry DB01099 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableTaking drug identified by DrugBank entry DB01099 details
Abnormal Concentrations
Not Available
Predicted Concentrations
BiospecimenValueOriginal ageOriginal sexOriginal conditionComments
Blood0.000 uMAdult (>18 years old)BothNormalPredicted based on drug qualities
Blood0.000 umol/mmol creatinineAdult (>18 years old)BothNormalPredicted based on drug qualities
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDDB01099
Phenol Explorer Compound IDNot Available
FooDB IDNot Available
KNApSAcK IDNot Available
Chemspider ID3249
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkFlucytosine
METLIN IDNot Available
PubChem Compound3366
PDB IDNot Available
ChEBI ID5100
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB ID
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
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. [PubMed:20843616 ]
  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. [PubMed:19359114 ]
  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. [PubMed:16831406 ]


General function:
Involved in DNA binding
Specific function:
Methylates CpG residues. Preferentially methylates hemimethylated DNA. Associates with DNA replication sites in S phase maintaining the methylation pattern in the newly synthesized strand, that is essential for epigenetic inheritance. Associates with chromatin during G2 and M phases to maintain DNA methylation independently of replication. It is responsible for maintaining methylation patterns established in development. DNA methylation is coordinated with methylation of histones. Mediates transcriptional repression by direct binding to HDAC2. In association with DNMT3B and via the recruitment of CTCFL/BORIS, involved in activation of BAG1 gene expression by modulating dimethylation of promoter histone H3 at H3K4 and H3K9.
Gene Name:
Uniprot ID:
Molecular weight:
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [PubMed:17139284 ]
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [PubMed:17016423 ]
  3. Shieh FK, Reich NO: AdoMet-dependent methyl-transfer: Glu119 is essential for DNA C5-cytosine methyltransferase M.HhaI. J Mol Biol. 2007 Nov 9;373(5):1157-68. Epub 2007 Aug 19. [PubMed:17897676 ]
  4. Wyszynski MW, Gabbara S, Kubareva EA, Romanova EA, Oretskaya TS, Gromova ES, Shabarova ZA, Bhagwat AS: The cysteine conserved among DNA cytosine methylases is required for methyl transfer, but not for specific DNA binding. Nucleic Acids Res. 1993 Jan 25;21(2):295-301. [PubMed:8441637 ]