Description

Fmoc-Cys(Tbu)-Oh is a protected cysteine derivative widely used in solid-phase peptide synthesis (SPPS). This compound is essential for the controlled incorporation of cysteine residues, a critical amino acid for forming disulfide bonds that define the tertiary structure and biological activity of peptides. It is a fundamental building block for researchers and manufacturers in the pharmaceutical, biotechnology, and life science sectors developing therapeutic peptides, diagnostic agents, and biochemical tools.

Application

• Solid-Phase Peptide Synthesis (SPPS): A key protected amino acid for the Fmoc/tBu strategy, enabling the sequential assembly of complex peptide chains.
• Therapeutic Peptide Production: Used in the synthesis of peptide-based drugs where cysteine is required for disulfide bridge formation, ensuring correct folding and stability.
• Bioconjugation and Labeling: The thiol group, after deprotection, serves as a reactive handle for site-specific conjugation with fluorescent dyes, polymers, or other biomolecules.
• Research & Development: A critical reagent in academic and industrial R&D for exploring protein-protein interactions, enzyme mechanisms, and novel peptide structures.
• Combinatorial Chemistry: Employed in libraries for high-throughput screening to discover new bioactive peptide leads.
• Antibody-Drug Conjugate (ADC) Linker Chemistry: Can be utilized in the synthesis of specialized linkers that connect cytotoxic drugs to antibodies.

Basic Information

Product Name	Fmoc-Cys(Tbu)-Oh
CAS No.	67436-13-9
Molecular Formula	C₂₂H₂₅NO₅S
Molecular Weight	415.50 g/mol
Synonyms	Fmoc-Cys(Trt)-OH (common alternative); N-[(9H-Fluoren-9-ylmethoxy)carbonyl]-S-(tert-butyl)-L-cysteine; Fmoc-S-tert-butyl-L-cysteine; Fmoc-Cysteine(Trt)-OH; Fmoc-L-Cys(Trt)-OH; N-Fmoc-S-tert-butylcysteine; (2R)-2-(9H-fluoren-9-ylmethoxycarbonylamino)-3-[(2-methylpropan-2-yl)sulfanyl]propanoic acid
EINECS	Contact for details

Quality Control

Our Fmoc-Cys(Tbu)-Oh is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing, including HPLC for purity, chiral analysis, and identity confirmation (IR, NMR) to ensure it meets the high standards required for peptide synthesis. A detailed Certificate of Analysis (COA) is provided with every shipment, confirming compliance with specifications.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 15-25°C. This product is hygroscopic (moisture-sensitive) and should be handled under dry conditions to maintain stability and purity.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Identification (HPLC)	Conforms to reference
Assay (HPLC)	≥98.5%
Optical Rotation	-20.0° to -24.0° (c=1 in DMF)
Water Content (KF)	≤0.5%
Heavy Metals	≤10 ppm
Residual Solvents (GC)	Meets ICH guidelines

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