Cysteine methyl ester

Cysteine methyl ester is the organic compound with the formula HSCH₂CH(NH₂)CO₂CH₃. It is a white solid substance, known as the methyl ester of the amino acid, cysteine.

Cysteine methyl ester

Clinical data
Other names	Methyl L-cysteinate
AHFS/Drugs.com	International Drug Names
Identifiers
IUPAC name methyl (2R)-2-amino-3-sulfanylpropanoate
CAS Number	2485-62-3 Y
PubChem CID	29145
ChemSpider	27113 Y
UNII	RQ6L463N3B
KEGG	D08164 Y
ChEBI	CHEBI:41531
ChEMBL	ChEMBL1231844
CompTox Dashboard (EPA)	DTXSID8048365
ECHA InfoCard	100.017.842
Chemical and physical data
Formula	C4H9NO2S
Molar mass	135.18 g·mol−1
3D model (JSmol)	Interactive image
SMILES COC(=O)C(CS)N
InChI InChI=1S/C4H9NO2S/c1-7-4(6)3(5)2-8/h3,8H,2,5H2,1H3/t3-/m0/s1 Y Key:MCYHPZGUONZRGO-VKHMYHEASA-N Y

Uses

Under the brand name Mecysteine, cysteine methyl ester is a commercial drug for mucolytic activity.^[1] The compound has an ability to break down or lower the viscosity of mucin-containing secretions or components of fluids by chronic and acute respiratory disorders. The drug is sold under the commercial names Delta in Paraguay, and Pectite and Zeotin in Japan.^[2]

Cysteine methyl ester is also used as a building block for synthesis of N,S-heterocycles.^[3][4]