Description

S-Cbz-L-Cysteine is a protected derivative of the amino acid L-cysteine, where the thiol group is safeguarded by a carboxybenzyl (Cbz) group. This protection is critical for preventing unwanted oxidation and enabling selective reactions in complex synthetic pathways, ensuring high yields and purity in the final product. It serves as a vital building block for researchers and manufacturers in the pharmaceutical and biotechnology sectors, particularly in the synthesis of peptides, active pharmaceutical ingredients (APIs), and biochemical probes.

Application

• Pharmaceutical Intermediate: A key chiral synthon in the synthesis of complex peptide-based drugs and active pharmaceutical ingredients (APIs).
• Peptide Synthesis: Used in solid-phase and solution-phase peptide synthesis (SPPS) to incorporate cysteine residues while protecting the thiol group from side reactions.
• Bioconjugation & Protein Engineering: Facilitates site-specific labeling and modification of proteins and antibodies due to its protected, yet selectively deprotectable, thiol functionality.
• Biochemical Research: Employed as a standard or reagent in studies involving redox biology, enzyme mechanisms, and thiol chemistry.
• Protecting Group Strategy: The Cbz group can be selectively removed under mild hydrogenolytic conditions, making it valuable in multi-step organic syntheses.

Basic Information

Product Name	S-Cbz-L-Cysteine
CAS No.	1625-72-5
Molecular Formula	C11H13NO4S
Molecular Weight	255.29 g/mol
Synonyms	N-Carboxybenzyl-L-cysteine; N-Cbz-L-cysteine; (S)-2-(((Benzyloxy)carbonyl)amino)-3-mercaptopropanoic acid; L-Cysteine, N-[(phenylmethoxy)carbonyl]-; Z-L-Cysteine; N-Benzyloxycarbonyl-L-cysteine; N-Carbobenzoxy-L-cysteine
EINECS	Contact for details

Quality Control

Our S-Cbz-L-Cysteine is produced under strict quality management systems to ensure batch-to-batch consistency and high purity. We offer material suitable for research and GMP-grade applications, with comprehensive testing against established in-house specifications. A Certificate of Analysis (COA) detailing purity, chiral purity, and impurity profiles is provided with each shipment to guarantee compliance with your project requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 2-8°C under an inert atmosphere (e.g., nitrogen or argon) due to its hygroscopic and easily oxidized nature. Allow the container to reach room temperature before opening to minimize moisture condensation.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥98.0%
Chiral Purity (HPLC)	≥99.0% (L-isomer)
Loss on Drying	≤1.0%
Residue on Ignition	≤0.1%
Heavy Metals	≤10 ppm

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