Histidine

C₆H₉N₃O₂

IUPAC: (2S)-2-Amino-3-(1H-imidazol-4-yl)propanoic acid

CAS: 71-00-1

Overview

Histidine is a conditionally essential amino acid containing an imidazole side chain. It is the precursor to histamine and plays a crucial role in enzyme active sites.

Composition

Element Symbol Atoms Atomic Mass
Hydrogen H 9 1.0080
Carbon C 6 12.0110
Nitrogen N 3 14.0070
Oxygen O 2 15.9990

Elemental Composition

H
Hydrogen ×9
5.8%
C
Carbon ×6
46.4%
N
Nitrogen ×3
27.1%
O
Oxygen ×2
20.6%

Uses

  • • Dietary supplement
  • • Pharmaceutical
  • • Metal chelation

Fun Facts

  • ✦ The imidazole group allows histidine to switch between protonated and neutral forms at physiological pH

Structure

SMILES

C1=C(NC=N1)CC(C(=O)O)N

Properties

Type
organic
State
solid
Molar Mass
155.16 g/mol
Density
1.4200 g/cm³
Melting Point
282.0 °C
Solubility
43 g/L at 25°C

Molecular Descriptors

Exact Mass
155.0695
XLogP
-3.2
TPSA
92.0 Ų
H-Bond Donors
3
H-Bond Acceptors
4
Rotatable Bonds
3
Heavy Atoms
11
Complexity
151.0

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 Histidine?
Histidine (C₆H₉N₃O₂) is a organic compound with the IUPAC name (2S)-2-Amino-3-(1H-imidazol-4-yl)propanoic acid.
What is the molecular weight of Histidine?
Histidine has a molar mass of 155.16 g/mol.
What state is Histidine at room temperature?
Histidine is a solid at room temperature.
Is Histidine organic or inorganic?
Histidine is classified as an organic compound.
What elements make up Histidine?
Histidine (C₆H₉N₃O₂) is composed of Hydrogen (H), Carbon (C), Nitrogen (N), Oxygen (O).