Description

L-Cysteine Methyl Ester Hydrochloride is a protected derivative of the essential amino acid L-Cysteine, where the thiol group is blocked and the carboxylic acid is esterified. This chemical modification enhances its stability and solubility in organic media, making it a crucial building block in peptide synthesis and pharmaceutical research. It is primarily utilized by research institutions and manufacturers in the pharmaceutical, biotechnology, and fine chemical sectors for developing novel therapeutic agents and biochemical probes.

Application

• Pharmaceutical Intermediates: A key chiral synthon in the synthesis of complex peptide-based drugs and active pharmaceutical ingredients (APIs).
• Peptide Synthesis: Serves as a protected cysteine residue in solid-phase and solution-phase peptide synthesis to prevent unwanted disulfide bond formation during assembly.
• Biochemical Research: Used in the study of protein structure, function, and enzyme mechanisms where controlled cysteine incorporation is required.
• Cosmetic & Personal Care: Employed in the research and development of advanced hair care and skin treatment formulations.
• Food & Flavor Industry: Investigated for potential use as a precursor in the production of certain flavor enhancers and processing aids.

Basic Information

Product Name	L-Cysteine Methyl Ester Hydrochloride
CAS No.	18598-63-5
Molecular Formula	C4H10ClNO2S
Molecular Weight	171.65 g/mol
Synonyms	L-Cysteine methyl ester HCl; Methyl L-cysteinate hydrochloride; H-Cys-OMe·HCl; (R)-2-Amino-3-mercaptopropionic acid methyl ester hydrochloride; Cysteine methyl ester hydrochloride; L-Cysteine methyl ester monohydrochloride; CME·HCl
EINECS	242-426-4

Quality Control

Our L-Cysteine Methyl Ester Hydrochloride is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including chiral purity verification, to ensure it meets high-purity standards suitable for research and synthesis applications. A Certificate of Analysis (COA) detailing specific results for assay, optical rotation, and impurity profiles is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive) and should be handled in a dry environment to prevent degradation.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥98.0%
Optical Rotation [α]	- Specific value provided on COA -
Loss on Drying	≤1.0%
Heavy Metals	≤20 ppm
Residue on Ignition	≤0.1%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.