For chemists engaged in peptide synthesis, understanding the precise properties of the building blocks is fundamental to successful outcomes. Boc-Cys(Acm)-OH is one such critical component, offering specific advantages due to its chemical structure and protective groups. This article explores the key features and properties that make this compound indispensable in the field.

The fundamental structure of Boc-Cys(Acm)-OH combines L-cysteine with two protective groups: the tert-Butoxycarbonyl (Boc) group on the alpha-amino terminus and the acetamidomethyl (Acm) group on the thiol side chain. The Boc group is acid-labile, meaning it can be readily removed under mild acidic conditions, a common step in Boc-based solid-phase peptide synthesis. The Acm group, however, is more stable to typical deprotection conditions, allowing for selective removal later in the synthesis, often in conjunction with disulfide bond formation.

Key physical and chemical properties of Boc-Cys(Acm)-OH include:

  • Appearance: Typically presented as a fine white powder, indicating a high degree of purity.
  • Molecular Formula: C11H20N2O5S. This formula dictates its molecular weight and chemical behavior.
  • Molecular Weight: Approximately 292.4 g/mol. This precise weight is critical for stoichiometric calculations in synthesis.
  • Melting Point: Ranges from 103-117°C. This property is a standard indicator of purity and can influence handling and storage.
  • CAS Number: 19746-37-3. This unique identifier ensures accurate product identification for procurement and regulatory purposes.
  • Solubility: While specific solubility data can vary, it is generally soluble in common organic solvents used in peptide synthesis.

The significance of these properties lies in their direct impact on synthesis efficiency and product quality. The stability of the Acm group during standard peptide coupling and Boc deprotection steps is a major advantage, preventing premature reactions of the cysteine thiol. This selectivity allows for the controlled introduction of disulfide bonds, often achieved through subsequent deprotection of the Acm group and oxidation.

Researchers and procurement specialists looking to buy Boc-Cys(Acm)-OH should prioritize sourcing from manufacturers who provide comprehensive specifications and ensure product consistency. A reliable supplier will detail these properties and offer technical support, ensuring that the purchased material meets the rigorous demands of advanced synthesis. Partnering with a manufacturer that understands these nuances is key to successful research and development in areas like peptide drug discovery.