Cytosine

Possibly Marketed Outside US

First approved in 2014

Details

Stereochemistry	ACHIRAL
Molecular Formula	C4H5N3O
Molecular Weight	111.102
Optical Activity	NONE
Defined Stereocenters	0 / 0
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

NC1=NC(=O)NC=C1

InChI

InChIKey=OPTASPLRGRRNAP-UHFFFAOYSA-N

InChI=1S/C4H5N3O/c5-3-1-2-6-4(8)7-3/h1-2H,(H3,5,6,7,8)

HIDE SMILES / InChI

Molecular Formula	C4H5N3O
Molecular Weight	111.102
Charge	0
Count

Stereochemistry	ACHIRAL
Additional Stereochemistry	No
Defined Stereocenters	0 / 0
E/Z Centers	0
Optical Activity	NONE

Description
Sources: https://themedicalbiochemistrypage.org/nucleic-acids.php | https://library.med.utah.edu/NetBiochem/pupyr/pp.htm

Cytosine is a pyrimidine nucleobase, one of the five main bases of nucleic acids. In DNA and RNA cytosine is paired with guanine. Only small amounts of cytosine administered with food are incorporated in DNA. The majority of cytosine is synthesized de-novo starting from carbamoyl phosphate.

CNS Activity

Originator

Approval Year

Conditions

Condition	Modality	Targets	Highest Phase	Product
Unknown 2596

PubMed

Title	Date	PubMed
The mechanism of DNA cytosine-5 methylation. Kinetic and mutational dissection of Hhai methyltransferase.	2001-06-15	11283006
Chimeras between single-stranded DNA-binding proteins from Escherichia coli and Mycobacterium tuberculosis reveal that their C-terminal domains interact with uracil DNA glycosylases.	2001-05-18	11279060
Optimized RNA targets of two closely related triple KH domain proteins, heterogeneous nuclear ribonucleoprotein K and alphaCP-2KL, suggest Distinct modes of RNA recognition.	2001-05-18	11278705
Cytosine methylation enhances mitoxantrone-DNA adduct formation at CpG dinucleotides.	2001-05-11	11278477
Actinomycin D binds strongly to d(TGTCATTG), a single-stranded DNA devoid of GpC sites.	2001-05-01	11318644
Treatment of adenovirus infections in patients undergoing allogeneic hematopoietic stem cell transplantation.	2001-05-01	11303263
Catechol estrogens induce oxidative DNA damage and estradiol enhances cell proliferation.	2001-05-01	11291067
Evolution of endogenous retrovirus-like elements of the woolly mammoth (Mammuthus primigenius) and its relatives.	2001-05	11319267
Pseudogenes, junk DNA, and the dynamics of Rickettsia genomes.	2001-05	11319266
The elevated GC content at exonic third sites is not evidence against neutralist models of isochore evolution.	2001-05	11319260
Glucocorticoid-induced DNA demethylation and gene memory during development.	2001-04-17	11296230
Association study of CAG repeats in the KCNN3 gene in Japanese patients with schizophrenia, schizoaffective disorder and bipolar disorder.	2001-04-15	11311923
Potent inhibition of hemangiosarcoma development in mice by cidofovir.	2001-04-15	11291040
Single molecule DNA sequencing in submicrometer channels: state of the art and future prospects.	2001-04-13	11257531
15-mer DNA duplexes containing an abasic site are thermodynamically more stable with adjacent purines than with pyrimidines.	2001-04-03	11300765
Changes in DNA methylation in neoplasia: pathophysiology and therapeutic implications.	2001-04-03	11281740
Suicide gene therapy: possible applications in haematopoietic disorders.	2001-04	11298856
The ganciclovir implant plus oral ganciclovir versus parenteral cidofovir for the treatment of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome: The Ganciclovir Cidofovir Cytomegalovirus Retinitis Trial.	2001-04	11292409
DNA methylation learns to fly.	2001-04	11275305
Low-energy (5-40 eV) electron-stimulated desorption of anions from physisorbed DNA bases.	2001-04	11260665
Solution structure of the SL1 RNA of the M1 double-stranded RNA virus of Saccharomyces cerevisiae.	2001-04	11259308
Base sequence-specific attack of stilbene estrogen metabolite(s) on the mitochondrial DNA: implications in the induction of instability in the mitochondrial genome in the kidney of Syrian hamsters.	2001-04	11254879
A-like guanine-guanine stacking in the aqueous DNA duplex of d(GGGGCCCC).	2001-03-23	11254379
Solution structure of an A-tract DNA bend.	2001-03-09	11237619
Molecular topology of polycyclic aromatic carcinogens determines DNA adduct conformation: a link to tumorigenic activity.	2001-03-09	11237618
High guanine-cytosine content is not an adaptation to high temperature: a comparative analysis amongst prokaryotes.	2001-03-07	11296861
Hierarchy of DNA damage recognition in Escherichia coli nucleotide excision repair.	2001-03-06	11258904
Tetraplex formation by the progressive myoclonus epilepsy type-1 repeat: implications for instability in the repeat expansion diseases.	2001-03-02	11240124
Comparative study of a novel nucleoside analogue (Troxatyl, troxacitabine, BCH-4556) and AraC against leukemic human tumor xenografts expressing high or low cytidine deaminase activity.	2001-03	11320667
Early diagnosis of adenovirus infection and treatment with cidofovir after bone marrow transplantation in children.	2001-03	11319592
Effect of chemical modifications of cytosine and guanine in a CpG-motif of oligonucleotides: structure-immunostimulatory activity relationships.	2001-03	11310616
Epigenetic regulation of human bone morphogenetic protein 6 gene expression in prostate cancer.	2001-03	11277266
Topical cidofovir for bowenoid papulosis in an HIV-infected patient.	2001-03	11260042
Alkylating agent and chromatin structure determine sequence context-dependent formation of alkylpurines.	2001-02-16	11237592
Suicide gene therapy for premalignant disease: a new strategy for the treatment of intraepithelial neoplasia.	2001-02	11313795
Isolation and frontier molecular orbital investigation of bioactive quinone-methide triterpenoids from the bark of Salacia petenensis.	2001-02	11270725
Size constraints for targeting post-transcriptional gene silencing and for RNA-directed methylation in Nicotiana benthamiana using a potato virus X vector.	2001-02	11260498
Characterization of DNA damage at purine residues in oligonucleotides and calf thymus DNA induced by the mutagen 1-nitrosoindole-3-acetonitrile.	2001-02	11258964
Confounded cytosine! Tinkering and the evolution of DNA.	2001-02	11252956
Host responses and persistence of vector genome following intrabronchial administration of an E1(-)E3(-) adenovirus gene transfer vector to normal individuals.	2001-02	11237677
Failure of cidofovir to reduce CMV-antigenemia in a child transplanted from a matched unrelated donor.	2001-02	11233794
In-situ FTIR study on adsorption and oxidation of native and thermally denatured calf thymus DNA at glassy carbon electrodes.	2001-01-31	11246748
Surveying CpG methylation at 5'-CCGG in the genomes of rice cultivars.	2001-01	11247604
Murine recombinant prion protein induces ordered aggregation of linear nucleic acids to condensed globular structures.	2001	11315641
A simple model based on mutation and selection explains trends in codon and amino-acid usage and GC composition within and across genomes.	2001	11305938
Prophylaxis against herpesvirus infections in transplant recipients.	2001	11270937
Suicide gene therapy for pediatric tumors.	2001	11269507
Imaging biochemistry: applications to breast cancer.	2001	11250743
UAG readthrough in mammalian cells: effect of upstream and downstream stop codon contexts reveal different signals.	2001	11242562
Regulation of gene expression by GC-rich DNA cis-elements.	2001	11237405

Patents

Sample Use Guides

In Vivo Use Guide

As a component of DNA, cytosine is ingested with a normal diet. Normally, a major amount of cytosine is excreted, and a small amount is incorporated into DNA of the gastrointestinal tract.

Route of Administration: Oral

In Vitro Use Guide

Unknown

Substance Class	Chemical Created by `admin` on `Mon Mar 31 17:34:30 GMT 2025` Edited by `admin` on `Mon Mar 31 17:34:30 GMT 2025`
Record UNII	8J337D1HZY
Record Status	`Validated (UNII)`
Record Version

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Name

Type

Language

NSC-27787

Preferred Name

English

Cytosine

Official Name

English

LAMIVUDINE IMPURITY C [USP IMPURITY]

Common Name

English

4-AMINOURACIL

Common Name

English

CYTOSINE [MI]

Common Name

English

Cytosine [WHO-DD]

Common Name

English

CYTOSINIMINE

Systematic Name

English

LAMIVUDINE IMPURITY E [EP IMPURITY]

Common Name

English

CYTOSINE [USP-RS]

Common Name

English

4-AMINOPYRIMIDIN-2(1H)-ONE

Systematic Name

English

Classification Tree Code System Code

EU-Orphan Drug

EU/3/07/476