Description

Boc-S-4-Methoxybenzyl-D-Cysteine is a high-purity, protected amino acid derivative essential for advanced peptide synthesis. This compound is specifically engineered to provide orthogonal protection for the cysteine thiol group, enabling precise and complex peptide chain assembly. It is a critical building block for researchers and manufacturers in the pharmaceutical and biotechnology sectors developing novel peptide-based therapeutics, diagnostics, and research tools.

Application

• Solid-Phase Peptide Synthesis (SPPS): A key intermediate for the controlled incorporation of D-cysteine residues into peptide sequences, particularly where the S-4-methoxybenzyl (Mob) protecting group is required.
• Pharmaceutical Research & Development: Used in the synthesis of peptide drug candidates, including constrained peptides, cyclic peptides, and those requiring specific disulfide bridge patterns.
• Bioconjugation and Chemical Biology: Serves as a precursor for creating thiol-reactive probes, linkers, or tags for protein/antibody-drug conjugates (ADCs) and labeling applications.
• Combinatorial Chemistry Libraries: Employed to generate diverse libraries of cysteine-containing peptides for high-throughput screening against biological targets.
• Process Development & Scale-Up: Supports the transition from laboratory-scale research to Good Manufacturing Practice (GMP) production of peptide active pharmaceutical ingredients (APIs).

Basic Information

Product Name	Boc-S-4-Methoxybenzyl-D-Cysteine
CAS No.	58290-35-0
Molecular Formula	C16H23NO5S
Molecular Weight	341.42 g/mol
Synonyms	N-(tert-Butoxycarbonyl)-S-(4-methoxybenzyl)-D-cysteine; Boc-Cys(Mob)-OH (D-isomer); D-Boc-Cys(Mob)-OH; (S)-2-((tert-Butoxycarbonyl)amino)-3-((4-methoxybenzyl)thio)propanoic acid; N-Boc-S-p-methoxybenzyl-D-cysteine; tert-Butyloxycarbonyl-S-(4-methoxybenzyl)-D-cysteine; Boc-D-Cys(Mob)-OH
EINECS	Contact for details

Quality Control

Our Boc-S-4-Methoxybenzyl-D-Cysteine is produced under stringent quality management systems to ensure batch-to-batch consistency and high purity, suitable for demanding research and development applications. Each lot is accompanied by a comprehensive Certificate of Analysis (COA) detailing purity, identity, and impurity profiles. We support compliance with relevant guidelines for advanced pharmaceutical intermediates.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 15-25°C. This material is hygroscopic (moisture-sensitive) and should be handled under dry conditions to maintain stability and purity. For long-term storage, consider desiccant and inert atmosphere.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (HPLC)	Conforms to reference standard
Identification (IR)	Conforms to structure
Assay (HPLC)	≥98.0%
Optical Rotation [α]	Contact for details
Water Content (KF)	≤1.0%
Heavy Metals	≤20 ppm
Residual Solvents (GC)	Complies with ICH guidelines

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