Cytidine

Not to be confused with cytosine, cysteine, cystine, or cytisine.

Cytidine (symbol C or Cyd) is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ribofuranose) via a β-N₁-glycosidic bond. Cytidine is a component of RNA. It is a white water-soluble solid^[2] that is only slightly soluble in ethanol.^[1]

Cytidine

Names
IUPAC name Cytidine
Systematic IUPAC name 4-Amino-1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]pyrimidin-2(1H)-one
Other names 4-Amino-1-β-D-ribofuranosyl-2(1H)-pyrimidinone[1] 4-Amino-1-[3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl]pyrimidin-2-one
Identifiers
CAS Number	65-46-3 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17562 Y
ChEMBL	ChEMBL95606 Y
ChemSpider	5940 Y
ECHA InfoCard	100.000.555
IUPHAR/BPS	4728
KEGG	D07769 Y
MeSH	Cytidine
PubChem CID	6175
UNII	5CSZ8459RP Y
CompTox Dashboard (EPA)	DTXSID60891552
InChI InChI=1S/C9H13N3O5/c10-5-1-2-12(9(16)11-5)8-7(15)6(14)4(3-13)17-8/h1-2,4,6-8,13-15H,3H2,(H2,10,11,16)/t4-,6-,7-,8-/m1/s1 Y Key: UHDGCWIWMRVCDJ-XVFCMESISA-N Y InChI=1/C9H13N3O5/c10-5-1-2-12(9(16)11-5)8-7(15)6(14)4(3-13)17-8/h1-2,4,6-8,13-15H,3H2,(H2,10,11,16)/t4-,6-,7-,8-/m1/s1 Key: UHDGCWIWMRVCDJ-XVFCMESIBD
SMILES O=C1/N=C(/N)\C=C/N1[C@@H]2O[C@@H]([C@@H](O)[C@H]2O)CO
Properties
Chemical formula	C9H13N3O5
Molar mass	243.217
Appearance	white, crystalline powder[2]
Melting point	230 °C (decomposes)[1]
Magnetic susceptibility (χ)	−123.7·10−6 cm3/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Dietary sources

Dietary sources of cytidine include foods with high RNA (ribonucleic acid) content,^[3] such as organ meats, brewer's yeast, as well as pyrimidine-rich foods such as beer. During digestion, RNA-rich foods are broken-down into ribosyl pyrimidines (cytidine and uridine), which are absorbed intact.^[3] In humans, dietary cytidine is converted into uridine,^[4] which is probably the compound behind cytidine's metabolic effects.

Cytidine analogues

A variety of cytidine analogues are known, some with potentially useful pharmacology. For example, KP-1461 is an anti-HIV agent that works as a viral mutagen,^[5] and zebularine exists in E. coli and is being examined for chemotherapy. Low doses of azacitidine and its analog decitabine have shown results against cancer through epigenetic demethylation.^[6]

Biological actions

In addition to its role as a pyrimidine component of RNA, cytidine has been found to control neuronal-glial glutamate cycling, with supplementation decreasing midfrontal/cerebral glutamate/glutamine levels.^[7] As such, cytidine has generated interest as a potential glutamatergic antidepressant drug.^[7]

Related compounds

• Deoxycytidine is cytosine attached to a deoxyribose.

Properties