3-Methylhistidine

3-Methylhistidine (3-MH) is a post-translationally modified amino acid which is excreted in human urine.^[1][2] Urinary concentration of 3-methylhistidine is a biomarker for skeletal muscle protein breakdown in humans who have been subject to muscle injury.^[1][3][4] Urinary 3-methylhistidine concentrations are also elevated from consumption of soy-based products and meat, particularly chicken.^[1]

3-Methylhistidine

Names
Systematic IUPAC name (2S)-2-Amino-3-(1-methyl-1H-imidazol-5-yl)propanoic acid
Identifiers
CAS Number	368-16-1 Y
3D model (JSmol)	Interactive image
Beilstein Reference	83651
ChEBI	CHEBI:27596
ChEMBL	ChEMBL3251670
ChemSpider	58494
ECHA InfoCard	100.006.095
EC Number	206-704-6
Gmelin Reference	1568650
KEGG	C01152
PubChem CID	64969
UNII	MEH8O8Y0H0 Y
CompTox Dashboard (EPA)	DTXSID90920521
InChI InChI=1S/C7H11N3O2/c1-10-4-9-3-5(10)2-6(8)7(11)12/h3-4,6H,2,8H2,1H3,(H,11,12)/t6-/m0/s1 Key: JDHILDINMRGULE-LURJTMIESA-N
SMILES CN1C=NC=C1CC(C(=O)O)N
Properties
Chemical formula	C7H11N3O2
Molar mass	169.184
Solubility in water	200 mg/mL at 25 °C[1][2]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Biochemistry

3-Methylhistidine is a metabolic product that is produced in the body via the enzymatic methylation of histidine during peptide bond synthesis and the methylation of actin and myosin.^[1][2]

Detection in body fluids

The normal concentration of 3-methylhistidine in the urine of healthy adult humans has been detected and quantified in a range of 3.63–69.27 micromoles per millimole (μmol/mmol) of creatinine, with most studies reporting the average urinary concentration between 15 and 20 μmol/mmol of creatinine.^[1] The average concentration of 3-methylhistidine in human blood plasma has been detected and quantified at 2.85 micromolar (μM) with a range of 0.0–5.9 μM.^[1] The average concentration of 3-methylhistidine in human cerebrospinal fluid (CSF) has been detected and quantified at 3.82 μM with a range of 1.39–6.25 μM.^[1]