Fmoc-Lys(Boc)-NCA (CAS 125814-22-4) is a protected amino acid N-carboxyanhydride (NCA) designed for solid-phase peptide synthesis (SPPS) and ring-opening polymerization (ROP) of polypeptides. It features orthogonal protecting groups: Fmoc (base-labile, for Nα) and Boc (acid-labile, for Nε of lysine), enabling selective deprotection in multi-step synthesis. The NCA ring allows controlled ROP to produce well-defined polylysine homopolymers or copolymers with tunable molecular weight and low dispersity. These polypeptides are widely used in biomedicine: drug delivery carriers, gene transfection vectors, tissue engineering scaffolds, and antimicrobial peptides. In SPPS, it serves as a pre-activated monomer to improve coupling efficiency and reduce racemization during lysine incorporation. It is also used in the synthesis of peptide-drug conjugates (PDCs) and stimuli-responsive polypeptide materials.

Fmoc-Lys(Boc)-NCA is classified as GHS07 (H315, H317, H319); moisture-sensitive. Inhalation: Dust may irritate respiratory tract; use local exhaust and dust mask. Skin Contact: May cause irritation and allergic skin reaction; wear nitrile gloves, avoid prolonged contact, wash skin after handling. Eye Contact: Causes serious eye irritation; wear safety goggles, rinse eyes with water ≥15 minutes if contact occurs. Ingestion: May cause gastrointestinal irritation; do not induce vomiting, seek medical aid. Chemical Hazards: NCA ring reacts violently with water, alcohols, amines, and strong bases—releases CO? and may cause pressure buildup; store under dry inert gas (N?/Ar). Thermal Hazard: Decomposes above 130 °C, releasing toxic fumes (CO, NO?). Disposal: Dispose via licensed hazardous waste provider; do not release to environment.