Description

L-Cysteine, S-(2-Oxoethyl)- (9Ci) is a chemically modified derivative of the amino acid L-cysteine, featuring a reactive 2-oxoethyl (glyoxyl) moiety attached to the sulfur atom. This functionalization makes it a valuable intermediate and building block in organic synthesis and pharmaceutical research, particularly for creating thioether linkages or introducing specific carbonyl reactivity. It is primarily utilized by research institutions, pharmaceutical developers, and fine chemical manufacturers engaged in advanced peptide chemistry, prodrug design, and the synthesis of novel bioactive compounds.

Application

• Pharmaceutical Intermediate: Key building block for synthesizing novel drug candidates, especially in peptide and protein modification.
• Bioconjugation Chemistry: Used for site-specific labeling or functionalization of proteins, antibodies, and other biomolecules via its reactive thioether group.
• Prodrug Synthesis: Serves as a linker or promoiety in the design of prodrugs to improve drug solubility, stability, or targeted delivery.
• Chemical Research: A versatile reagent in organic synthesis for exploring new reactions involving cysteine derivatives and carbonyl compounds.
• Biochemical Tool: Used in biochemical studies to investigate enzyme mechanisms or to create custom cross-linking agents.

Basic Information

Product Name	L-Cysteine, S-(2-Oxoethyl)- (9Ci)
CAS No.	141814-32-6
Molecular Formula	C5H9NO3S
Molecular Weight	163.19 g/mol
Synonyms	S-(2-Oxoethyl)-L-cysteine; L-Cysteine S-glyoxylate; (R)-2-Amino-3-((2-oxoethyl)thio)propanoic acid; Glyoxylic acid cysteine adduct; 2-(Carboxymethylthio)-2-aminopropionic acid; Cysteine-glyoxylate adduct; NSC 339586
EINECS	Contact for details

Quality Control

Our L-Cysteine, S-(2-Oxoethyl)- is produced under strict quality management protocols. Each batch undergoes comprehensive analytical testing, including HPLC for purity, chiral analysis, and identity confirmation (IR, NMR), to ensure it meets exacting standards for research and development use. A detailed Certificate of Analysis (COA) documenting all test results is provided with every shipment to guarantee traceability and compliance with your specifications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated place at a controlled room temperature (15-25°C). Due to its hygroscopic nature, the container must be kept tightly sealed after opening to minimize exposure to atmospheric moisture.

Specification

Item	Specification
Appearance	White to off-white powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Optical Rotation	Specific range available on COA
Water Content (KF)	≤ 5.0%
Heavy Metals	< 20 ppm
Residue on Ignition	< 0.5%

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