Cytosine

C₄H₅N₃O

IUPAC: 4-Aminopyrimidin-2(1H)-one

CAS: 71-30-7

Overview

Cytosine is a pyrimidine nucleobase that pairs with guanine in both DNA and RNA through three hydrogen bonds. In DNA, cytosine can be methylated (5-methylcytosine), which plays a key role in epigenetic gene regulation without changing the DNA sequence.

Composition

Element Symbol Atoms Atomic Mass
Hydrogen H 5 1.0080
Carbon C 4 12.0110
Nitrogen N 3 14.0070
Oxygen O 1 15.9990

Elemental Composition

H
Hydrogen ×5
4.5%
C
Carbon ×4
43.2%
N
Nitrogen ×3
37.8%
O
Oxygen ×1
14.4%

Uses

  • • DNA/RNA base pair component
  • • Epigenetics research (methylation)
  • • Molecular biology
  • • Genetic analysis

Fun Facts

  • ✦ Cytosine methylation is a key mechanism of epigenetics, allowing gene expression changes without DNA sequence changes

Safety

  • ⚠ Low toxicity

Structure

SMILES

C1=C(NC(=O)N=C1)N

Properties

Type
organic
State
solid
Molar Mass
111.10 g/mol
Density
1.5500 g/cm³
Melting Point
320.0 °C
Solubility
7.69 g/L at 25°C

Molecular Descriptors

Exact Mass
111.0433
XLogP
-1.7
TPSA
67.5 Ų
H-Bond Donors
2
H-Bond Acceptors
2
Rotatable Bonds
0
Heavy Atoms
8
Complexity
170.0

Also Known As

Cytosine

Related Compounds

1,2-Dichloroethane

C₂H₄Cl₂

1,3-Butadiene

C₄H₆

1,4-Dioxane

C₄H₈O₂

1-Butanol

C₄H₁₀O

2-Propanol

C₃H₈O

Acetaldehyde

CH₃CHO

Acetamide

C₂H₅NO

Acetic Anhydride

C₄H₆O₃

Acetone

(CH₃)₂CO

Acetonitrile

C₂H₃N

Frequently Asked Questions

What is Cytosine?
Cytosine (C₄H₅N₃O) is a organic compound with the IUPAC name 4-Aminopyrimidin-2(1H)-one.
What is the molecular weight of Cytosine?
Cytosine has a molar mass of 111.102 g/mol.
What state is Cytosine at room temperature?
Cytosine is a solid at room temperature.
Is Cytosine organic or inorganic?
Cytosine is classified as an organic compound.
What elements make up Cytosine?
Cytosine (C₄H₅N₃O) is composed of Hydrogen (H), Carbon (C), Nitrogen (N), Oxygen (O).