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Record Information
Version4.0
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2020-02-27 20:29:59 UTC
HMDB IDHMDB0000630
Secondary Accession Numbers
  • HMDB00630
Metabolite Identification
Common NameCytosine
DescriptionCytosine, also known as C, belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. Cytosine is a strong basic compound (based on its pKa). Cytosine exists in all living species, ranging from bacteria to humans. In humans, cytosine is involved in the metabolic disorder called the mngie (mitochondrial neurogastrointestinal encephalopathy) pathway. Outside of the human body, cytosine has been detected, but not quantified in, several different foods, such as okra, italian oregano, cinnamons, anises, and soft-necked garlics. This could make cytosine a potential biomarker for the consumption of these foods. Cytosine (; C) is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). When found as the second base in a codon, the third is always interchangeable. In Watson-Crick base pairing, it forms three hydrogen bonds with guanine. A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year. Cytosine likely formed within some meteorite parent bodies, however did not persist within these bodies due to an effective deamination reaction into uracil. The implications of deamination on 5-hydroxymethylcytosine, on the other hand, remains less understood.
Structure
Data?1582752145
Synonyms
ValueSource
4-Amino-2(1H)-pyrimidinoneChEBI
4-Amino-2-hydroxypyrimidineChEBI
CChEBI
CytChEBI
CytosinChEBI
ZytosinChEBI
4-Amino-2-oxo-1,2-dihydropyrimidineHMDB
4-AminouracilHMDB
CytosinimineHMDB
Chemical FormulaC4H5N3O
Average Molecular Weight111.102
Monoisotopic Molecular Weight111.043261797
IUPAC Name6-amino-1,2-dihydropyrimidin-2-one
Traditional Name2(1H)-pyrimidinone, 6-amino-
CAS Registry Number71-30-7
SMILES
NC1=CC=NC(=O)N1
InChI Identifier
InChI=1S/C4H5N3O/c5-3-1-2-6-4(8)7-3/h1-2H,(H3,5,6,7,8)
InChI KeyOPTASPLRGRRNAP-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. 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 ParentPyrimidones
Alternative Parents
Substituents
  • Pyrimidone
  • Aminopyrimidine
  • Hydropyrimidine
  • Heteroaromatic compound
  • Azacycle
  • Organic nitrogen compound
  • Organic oxygen compound
  • Organopnictogen compound
  • Organic oxide
  • Hydrocarbon derivative
  • Primary amine
  • Organooxygen compound
  • Organonitrogen compound
  • Amine
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External Descriptors
Ontology
Disposition

Route of exposure:

Source:

Biological location:

Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting Point> 300 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility8 mg/mLNot Available
LogP-1.73HANSCH,C ET AL. (1995)
Predicted Properties
PropertyValueSource
Water Solubility30.9 g/LALOGPS
logP-0.94ALOGPS
logP-1.1ChemAxon
logS-0.56ALOGPS
pKa (Strongest Acidic)9.83ChemAxon
pKa (Strongest Basic)-0.06ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area67.48 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity38.01 m³·mol⁻¹ChemAxon
Polarizability9.88 ųChemAxon
Number of Rings1ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (Non-derivatized)splash10-0udm-3970000000-a0532c16ce6140949915Spectrum
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-0udl-4790000000-f8d777863969fe9feeeeSpectrum
GC-MSGC-MS Spectrum - GC-MS (3 TMS)splash10-0h6s-2914000000-5c0c43de53d8e6d5ff65Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0udm-3970000000-a0532c16ce6140949915Spectrum
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-0udl-4790000000-f8d777863969fe9feeeeSpectrum
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-0h6s-2914000000-5c0c43de53d8e6d5ff65Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0f6w-4960000000-b053578e0f2ae00d0808Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0gxt-0914000000-bdca724db358d4bc5ccbSpectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-03di-9400000000-109300546706ee372e62Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-03di-1900000000-ce9c385be713873945a4Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-00kf-9100000000-5d27ff55f5080da7aaf0Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-0006-9100000000-585d7d52c8ceb70d1b25Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-03k9-0970000000-1491957a90e606f28d03Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0006-9000000000-f79bcd2133156449152cSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-03di-0900000000-155769b79f7f2d14ee92Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-03di-0900000000-4b1d0c842bcd05ceed1bSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-03di-0910000000-7cd7c6a6f6e7c02ed6f1Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0006-9000000000-71a5fe9af8fc82824d54Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-014i-0900000000-a210a634771936e0ffd6Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-03di-0900000000-084e35ced5f5834ca93eSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 10V, Negativesplash10-03di-0900000000-d23ab5cfeba2d0a6ccffSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 20V, Negativesplash10-02tc-9500000000-3b81b2a441135c25b1e3Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 30V, Negativesplash10-00kf-9000000000-e57731b8ed024624cf7aSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 40V, Negativesplash10-0006-9000000000-a1679050e95cc271b8b7Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 50V, Negativesplash10-0006-9000000000-57b23eb60e1f7ce1ca97Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-03di-0900000000-d23ab5cfeba2d0a6ccffSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-02tc-9500000000-b9d5621a816bed354c10Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-00kf-9000000000-e57731b8ed024624cf7aSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-03di-1900000000-4047bc076c5529ab5953Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-03dj-9600000000-4b29d871234eed6b5e40Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0uxv-9000000000-e7c1aa90d5d06c5c13b4Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-03di-2900000000-b19c12744f9718502007Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-014i-9100000000-1cf86d26f0f1d0794e0dSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0006-9000000000-51460ed94e186a6f38e0Spectrum
1D NMR13C NMR SpectrumNot AvailableSpectrum
1D NMR1H NMR SpectrumNot AvailableSpectrum
1D NMR1H NMR SpectrumNot AvailableSpectrum
1D NMR13C NMR SpectrumNot AvailableSpectrum
1D NMR1H NMR SpectrumNot AvailableSpectrum
2D NMR[1H,1H] 2D NMR SpectrumNot AvailableSpectrum
2D NMR[1H,13C] 2D NMR SpectrumNot AvailableSpectrum
Biological Properties
Cellular Locations
  • Extracellular
Biospecimen Locations
  • Blood
  • Feces
  • Urine
Tissue Locations
  • Fibroblasts
  • Gut
  • Muscle
  • Neuron
  • Placenta
  • Plasma
  • Prostate
  • Skeletal Muscle
  • Skin
  • Spleen
  • Testes
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified6.4 +/- 8.5 uMAdult (>18 years old)BothNormal details
FecesDetected but not Quantified Children (6 - 18 years old)BothNormal details
FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedNormal details
FecesDetected but not Quantified Adult (>18 years old)Both
Normal
details
FecesDetected but not Quantified Adult (>18 years old)Both
Normal
details
FecesDetected but not Quantified Adult (>18 years old)Both
Normal
details
FecesDetected but not Quantified Not SpecifiedNot Specified
Normal
details
FecesDetected but not Quantified Infant (0-1 year old)Both
Normal
details
UrineDetected and Quantified1.1-10.7 umol/mmol creatinineNewborn (0-30 days old)Both
Normal
details
UrineDetected and Quantified4.1 (1.1-10.7) umol/mmol creatinineAdult (>18 years old)Both
Normal
details
Abnormal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
FecesDetected but not Quantified Children (6 - 18 years old)BothCrohns disease details
FecesDetected but not Quantified Children (6 - 18 years old)BothUlcerative colitis details
FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedCrohns disease details
FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedUlcerative colitis details
FecesDetected but not Quantified Children (6 - 18 years old)Not SpecifiedUnclassified IBD details
FecesDetected but not Quantified Adult (>18 years old)Both
Colorectal cancer
details
FecesDetected but not Quantified Adult (>18 years old)Both
Colorectal cancer
details
UrineDetected but not Quantified Adult (>18 years old)BothBladder cancer details
Associated Disorders and Diseases
Disease References
Crohn's disease
  1. Kolho KL, Pessia A, Jaakkola T, de Vos WM, Velagapudi V: Faecal and Serum Metabolomics in Paediatric Inflammatory Bowel Disease. J Crohns Colitis. 2017 Mar 1;11(3):321-334. doi: 10.1093/ecco-jcc/jjw158. [PubMed:27609529 ]
Ulcerative colitis
  1. Kolho KL, Pessia A, Jaakkola T, de Vos WM, Velagapudi V: Faecal and Serum Metabolomics in Paediatric Inflammatory Bowel Disease. J Crohns Colitis. 2017 Mar 1;11(3):321-334. doi: 10.1093/ecco-jcc/jjw158. [PubMed:27609529 ]
Colorectal cancer
  1. Sinha R, Ahn J, Sampson JN, Shi J, Yu G, Xiong X, Hayes RB, Goedert JJ: Fecal Microbiota, Fecal Metabolome, and Colorectal Cancer Interrelations. PLoS One. 2016 Mar 25;11(3):e0152126. doi: 10.1371/journal.pone.0152126. eCollection 2016. [PubMed:27015276 ]
  2. Goedert JJ, Sampson JN, Moore SC, Xiao Q, Xiong X, Hayes RB, Ahn J, Shi J, Sinha R: Fecal metabolomics: assay performance and association with colorectal cancer. Carcinogenesis. 2014 Sep;35(9):2089-96. doi: 10.1093/carcin/bgu131. Epub 2014 Jul 18. [PubMed:25037050 ]
Associated OMIM IDs
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FoodDB IDFDB022151
KNApSAcK IDC00001498
Chemspider ID577
KEGG Compound IDC00380
BioCyc IDCYTOSINE
BiGG ID34812
Wikipedia LinkCytosine
METLIN ID283
PubChem Compound597
PDB IDNot Available
ChEBI ID16040
Food Biomarker OntologyNot Available
VMH IDNot Available
References
Synthesis ReferenceHitchings, George H.; Elion, Gertrude B.; Falco, Elvira A.; Russell, Peter B. New synthesis of cytosine and 5-methylcytosine. Journal of Biological Chemistry (1949), 177 357-60.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Harvey BG, Maroni J, O'Donoghue KA, Chu KW, Muscat JC, Pippo AL, Wright CE, Hollmann C, Wisnivesky JP, Kessler PD, Rasmussen HS, Rosengart TK, Crystal RG: Safety of local delivery of low- and intermediate-dose adenovirus gene transfer vectors to individuals with a spectrum of morbid conditions. Hum Gene Ther. 2002 Jan 1;13(1):15-63. [PubMed:11779412 ]
  2. Cheng JC, Yoo CB, Weisenberger DJ, Chuang J, Wozniak C, Liang G, Marquez VE, Greer S, Orntoft TF, Thykjaer T, Jones PA: Preferential response of cancer cells to zebularine. Cancer Cell. 2004 Aug;6(2):151-8. [PubMed:15324698 ]
  3. Carotti D, Funiciello S, Lavia P, Caiafa P, Strom R: Different effects of histone H1 on de novo DNA methylation in vitro depend on both the DNA base composition and the DNA methyltransferase. Biochemistry. 1996 Sep 10;35(36):11660-7. [PubMed:8794746 ]
  4. Tawa R, Ueno S, Yamamoto K, Yamamoto Y, Sagisaka K, Katakura R, Kayama T, Yoshimoto T, Sakurai H, Ono T: Methylated cytosine level in human liver DNA does not decline in aging process. Mech Ageing Dev. 1992 Mar 1;62(3):255-61. [PubMed:1583911 ]
  5. Tsuchiya K, Tajima H, Yamada M, Takahashi H, Kuwae T, Sunaga K, Katsube N, Ishitani R: Disclosure of a pro-apoptotic glyceraldehyde-3-phosphate dehydrogenase promoter: anti-dementia drugs depress its activation in apoptosis. Life Sci. 2004 May 14;74(26):3245-58. [PubMed:15094325 ]
  6. Putta MR, Zhu F, Li Y, Bhagat L, Cong Y, Kandimalla ER, Agrawal S: Novel oligodeoxynucleotide agonists of TLR9 containing N3-Me-dC or N1-Me-dG modifications. Nucleic Acids Res. 2006 Jun 23;34(11):3231-8. Print 2006. [PubMed:16798912 ]
  7. Bawdon RE, Sobhi S, Dax J: The transfer of anti-human immunodeficiency virus nucleoside compounds by the term human placenta. Am J Obstet Gynecol. 1992 Dec;167(6):1570-4. [PubMed:1335207 ]
  8. Sawamura D, Abe R, Goto M, Akiyama M, Hemmi H, Akira S, Shimizu H: Direct injection of plasmid DNA into the skin induces dermatitis by activation of monocytes through toll-like receptor 9. J Gene Med. 2005 May;7(5):664-71. [PubMed:15655803 ]
  9. Thajeb P, Ma YS, Tzen CY, Chuang CK, Wu TY, Chen SC, Wei YH: Oculopharyngeal somatic myopathy in a patient with a novel large-scale 3,399 bp deletion and a homoplasmic T5814C transition of the mitochondrial DNA. Clin Neurol Neurosurg. 2006 Jun;108(4):407-10. [PubMed:16644408 ]
  10. Sigalotti L, Coral S, Nardi G, Spessotto A, Cortini E, Cattarossi I, Colizzi F, Altomonte M, Maio M: Promoter methylation controls the expression of MAGE2, 3 and 4 genes in human cutaneous melanoma. J Immunother. 2002 Jan-Feb;25(1):16-26. [PubMed:11924907 ]
  11. Costa E, Grayson DR, Mitchell CP, Tremolizzo L, Veldic M, Guidotti A: GABAergic cortical neuron chromatin as a putative target to treat schizophrenia vulnerability. Crit Rev Neurobiol. 2003;15(2):121-42. [PubMed:14977367 ]
  12. Machwe A, Orren DK, Bohr VA: Accelerated methylation of ribosomal RNA genes during the cellular senescence of Werner syndrome fibroblasts. FASEB J. 2000 Sep;14(12):1715-24. [PubMed:10973920 ]
  13. Rodriguez Ortner E, Hayes RB, Weissfeld J, Gelmann EP: Effect of homeodomain protein NKX3.1 R52C polymorphism on prostate gland size. Urology. 2006 Feb;67(2):311-5. Epub 2006 Jan 25. [PubMed:16442598 ]
  14. Elshenawy S, Pinney SE, Stuart T, Doulias PT, Zura G, Parry S, Elovitz MA, Bennett MJ, Bansal A, Strauss JF 3rd, Ischiropoulos H, Simmons RA: The Metabolomic Signature of the Placenta in Spontaneous Preterm Birth. Int J Mol Sci. 2020 Feb 4;21(3). pii: ijms21031043. doi: 10.3390/ijms21031043. [PubMed:32033212 ]

Enzymes

General function:
Involved in DNA binding
Specific function:
Binds CpG islands in promoters where the DNA is methylated at position 5 of cytosine within CpG dinucleotides. Binds hemi-methylated DNA as well. Recruits histone deacetylases and DNA methyltransferases. Acts as transcriptional repressor and plays a role in gene silencing. Isoform 1 may enhance the activation of some unmethylated cAMP-responsive promoters. Reports about DNA demethylase activity of isoform 2 are contradictory
Gene Name:
MBD2
Uniprot ID:
Q9UBB5
Molecular weight:
43254.3
General function:
Involved in nucleotide binding
Specific function:
Essential component of the apolipoprotein B mRNA editing enzyme complex which is responsible for the postranscriptional editing of a CAA codon for Gln to a UAA codon for stop in APOB mRNA. Binds to APOB mRNA and is probably responsible for docking the catalytic subunit, APOBEC1, to the mRNA to allow it to deaminate its target cytosine. The complex also protects the edited APOB mRNA from nonsense-mediated decay
Gene Name:
A1CF
Uniprot ID:
Q9NQ94
Molecular weight:
65202.0
General function:
Involved in DNA binding
Specific function:
Transcriptional repressor that binds CpG islands in promoters where the DNA is methylated at position 5 of cytosine within CpG dinucleotides. Binding is abolished by the presence of 7-mG that is produced by DNA damage by methylmethanesulfonate (MMS). Acts as transcriptional repressor and plays a role in gene silencing by recruiting AFT7IP, which in turn recruits factors such as the histone methyltransferase SETDB1. Probably forms a complex with SETDB1 and ATF7IP that represses transcription and couples DNA methylation and histone 'Lys-9' trimethylation. Isoform 1 and isoform 2 can also repress transcription from unmethylated promoters
Gene Name:
MBD1
Uniprot ID:
Q9UIS9
Molecular weight:
66606.5