Description

S-Benzyl-L-Cysteine is a protected derivative of the essential amino acid L-cysteine, featuring a benzyl group on the sulfur atom. This modification is critical for its primary role as a key chiral building block and protecting group reagent in sophisticated organic synthesis, particularly for peptides and pharmaceuticals. It is an indispensable raw material for researchers and manufacturers in the pharmaceutical, biotechnology, and fine chemical industries who require high-purity intermediates for complex molecular construction.

Application

• Pharmaceutical Intermediate: Serves as a crucial chiral synthon in the synthesis of active pharmaceutical ingredients (APIs), especially for drugs targeting the central nervous system and metabolic disorders.
• Peptide Synthesis: Used as a protected cysteine residue in solid-phase and solution-phase peptide synthesis, preventing unwanted disulfide bond formation during the assembly process.
• Bioconjugation & Protein Engineering: Acts as a handle for site-specific modification of proteins and antibodies through thiol-reactive chemistry, enabling drug-antibody conjugation (ADC) and labeling.
• Biochemical Research: Employed as a substrate or inhibitor in enzymatic studies and as a standard in analytical method development for amino acid analysis.
• Asymmetric Synthesis Catalyst: Utilized in the preparation of chiral ligands and organocatalysts for enantioselective transformations.
• Nutritional Supplement Precursor: Can be used in the controlled synthesis of cysteine derivatives for specialized nutraceutical applications.

Basic Information

Product Name	S-Benzyl-L-Cysteine
CAS No.	3054-01-1
Molecular Formula	C10H13NO2S
Molecular Weight	211.28 g/mol
Synonyms	(R)-2-Amino-3-(benzylthio)propanoic acid; L-Cysteine, S-benzyl-; S-Benzylcysteine; NSC 3349; H-Cys(Bzl)-OH; Bzl-Cys-OH; S-Benzyl-L-cystein; Benzyl L-cysteine
EINECS	221-281-5

Quality Control

Our S-Benzyl-L-Cysteine is manufactured under strict quality management systems. Every batch undergoes comprehensive analytical testing to ensure it meets the high-purity standards required for pharmaceutical and research applications. A detailed Certificate of Analysis (COA) is provided with each shipment, confirming specifications for identity, purity (by HPLC), chiral purity, and related substances. We support compliance with cGMP, ICH guidelines, and relevant pharmacopeial standards (USP/EP) for advanced intermediates.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at controlled room temperature (15-25°C). This product is hygroscopic (moisture-sensitive); the container must be kept tightly sealed in a dry environment to prevent degradation. For long-term storage, consider using desiccants.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Identification (HPLC)	Retention time matches reference standard
Assay (HPLC)	≥98.5%
Chiral Purity (HPLC)	≥99.0% (L-Isomer)
Loss on Drying	≤0.5%
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.