MPP+

MPP+
IUPAC name 1-Methyl-4-phenylpyridin-1-ium
Other names Cyperquat
Identifiers
CAS number	39794-99-5 N
PubChem	39484
ChemSpider	36101 Y
EC number	248-939-7
MeSH	1-Methyl-4-phenylpyridinium
ChEBI	CHEBI:641 Y
ChEMBL	CHEMBL311617 Y
Jmol-3D images	Image 1
SMILES C[n+]1=cc=c(c=c1)c2=cc=cc=c2
InChI InChI=1S/C12H12N/c1-13-9-7-12(8-10-13)11-5-3-2-4-6-11/h2-10H,1H3/q+1 Y Key: FMGYKKMPNATWHP-UHFFFAOYSA-N Y
Properties
Molecular formula	C12H12N+
Molar mass	170.25 g/mol
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

MPP+ (1-methyl-4-phenylpyridinium) is a positively charged molecule with chemical formula C₁₂H₁₂N⁺. It is toxic and acts by interfering with oxidative phosphorylation in mitochondria, causing depletion of ATP and cell death. It also inhibits the synthesis of catecholamines, reduces levels of dopamine and cardiac norepinephrine, and inactivates tyrosine hydroxylase.

The neurotoxin MPTP is converted in the brain into MPP+ by the enzyme MAO-B, causing parkinsonism in primates by killing certain dopamine-producing neurons in the substantia nigra.

The chloride of MPP+ has been used as a herbicide under the trade name cyperquat and is structurally similar to the herbicide paraquat.