MSPI (nerve agent)

{{Chembox

| Name = MSPI

| OtherNames = MSMPID

| ImageFile = MSPI structure.png

| Section1 = {{Chembox Identifiers

| CASNo = 70951-04-1

| PubChem = 51213

| ChemSpiderID = 46405

| StdInChI=1S/C5H9N2O2PS/c1-6-3-4-7(5-6)10(8,9)11-2/h3-5H,1-2H3

| StdInChIKey = QSLFDILMORXPKP-UHFFFAOYSA-N

| SMILES = C[N+]1=CN(C=C1)P(=O)([O-])SC

}}

| Section2 = {{Chembox Properties

| C=5|H=9|N=2|O=2|P=1|S=1

}}

| Section3 = {{Chembox Hazards

| LD50 = 3.15 mg/kg (mice, subcutaneous)

}}

}}

MSPI is an irreversible acetylcholinesterase inhibitor. MSPI reacts with the acetylcholinesterase to form an aged enzyme adduct that can't be reactivated by cholinesterase reactivators.{{cite journal |last1=Chabrier |first1=P. E. |last2=Jacob |first2=J. |title=In vivo and in vitro inhibition of cholinesterase by methyl-1 (S methyl phosphoryl-3) imidazolium (MSPI), a model of an "instantly" aged phosphorylated enzyme |journal=Archives of Toxicology |date=May 1980 |volume=45 |issue=1 |pages=15–20 |doi=10.1007/BF00303290|pmid=7396718 |bibcode=1980ArTox..45...15C |s2cid=24108114 }}