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Key Documents

M1387

Sigma-Aldrich

4-Methylpyrazole hydrochloride

alcohol dehydrogenase inhibitor

Synonym(s):

Fomepizole

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About This Item

Empirical Formula (Hill Notation):
C4H6N2 · HCl
CAS Number:
Molecular Weight:
118.56
MDL number:
UNSPSC Code:
12352202
PubChem Substance ID:
NACRES:
NA.77

biological source

synthetic (organic)

Assay

≥95%

form

powder

mp

157-159  °C

solubility

methanol: 100 mg/mL, clear, colorless to yellow

storage temp.

2-8°C

SMILES string

Cl.Cc1cn[nH]c1

InChI

1S/C4H6N2.ClH/c1-4-2-5-6-3-4;/h2-3H,1H3,(H,5,6);1H

InChI key

PUCXJHNDMYZOHG-UHFFFAOYSA-N

Gene Information

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Application

4-Methylpyrazole hydrochloride has been used:
  • as a cytochrome P450 2E1 inhibitor
  • as cytochrome P450 2E1 and alcohol dehydrogenase inhibitor in 1C11 neural progenitor cells
  • to inhibit ethanol oxidation in VL-17A cells expressing alcohol dehydrogenase and HepG2 cells

Useful as an antidote in methanol and ethylene glycol poisoning.

Biochem/physiol Actions

4-Methylpyrazole (4MP) inhibits ethanol oxidation in liver microsomes. It also blocks the c-Jun N-terminal kinase (JNK) activation in in vitro liver injury models.
Alcohol dehydrogenase inhibitor

Pictograms

Exclamation mark

Signal Word

Warning

Hazard Statements

Hazard Classifications

Eye Irrit. 2 - Skin Irrit. 2 - STOT SE 3

Target Organs

Respiratory system

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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D E Feierman et al.
The Biochemical journal, 239(3), 671-677 (1986-11-01)
Pyrazole and 4-methylpyrazole, which are inhibitors of alcohol dehydrogenase, were also found to be effective inhibitors of the oxidation of ethanol by liver microsomes (microsomal fractions) in vitro. Ethanol oxidation by microsomes from rats previously treated for 2 or 3
Katherine J Lepik et al.
Clinical toxicology (Philadelphia, Pa.), 49(5), 391-401 (2011-07-12)
Little is known about medication errors which occur with the antidotes ethanol and fomepizole, used for treatment of methanol and ethylene glycol poisoning. Study objectives were to describe and compare the frequency, type, outcome and underlying causes of medication errors
Trang T T Nguyen et al.
Critical reviews in immunology, 36(2), 163-177 (2016-12-03)
Most serum immunoglobulin M (IgM) is "natural IgM", which is produced apparently spontaneously by a distinct subset of B cells requiring no exogenous antigenic or microbial stimuli. Natural IgM is an evolutionarily conserved molecule and reacts with a variety of
Rachael Racine et al.
Immunology letters, 125(2), 79-85 (2009-06-23)
Much has been learned about the structure, function, and production of IgM, since the antibody's initial characterization. It is widely accepted that IgM provides a first line of defense during microbial infections, prior to the generation of adaptive, high-affinity IgG
Kenneth E McMartin et al.
Clinical toxicology (Philadelphia, Pa.), 50(5), 375-383 (2012-05-05)
Fomepizole, a potent inhibitor of alcohol dehydrogenase, has replaced ethanol as antidote for methanol and ethylene glycol intoxications because of a longer duration of action and fewer adverse effects. Prior human studies have indicated that single doses of fomepizole are

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