Fmoc-Lys(Trt)-OH

Fmoc-Lys(Trt)-OH is a fundamental building block in Fmoc/tBu solid-phase peptide synthesis, enabling the incorporation of lysine — a positively charged amino acid critical for peptide solubility, cellular uptake, and receptor interactions — into synthetic peptide sequences. The Fmoc group on the α-amino position allows for facile deprotection with piperidine during chain elongation, while the trityl group on the ε-amino side chain provides acid-labile protection that is cleanly removed during final TFA-mediated cleavage from the resin. Fmoc-Lys(Trt)-OH is widely utilized in the synthesis of side-chain to side-chain cyclic peptides, oligolysine cores for multiantigenic peptides (MAPs), and template-assembled synthetic proteins (TASPs). As one of the most frequently used orthogonally protected amino acids, Fmoc-Lys(Trt)-OH serves as an essential reagent for researchers developing peptide therapeutics, peptide vaccines, and protein engineering tools. The high purity of Fmoc-Lys(Trt)-OH (≥99.8% enantiomeric excess by chiral HPLC) ensures that the stereochemical integrity of the L-lysine scaffold is preserved throughout peptide assembly.

Product Parameters

Product Advantages

 Orthogonal Protection for Precision Peptide Synthesis

Fmoc-Lys(Trt)-OH features a base-labile Fmoc group on the α-amino position and an acid-labile trityl (Trt) group on the ε-amino side chain. This orthogonal protection strategy enables selective deprotection — the Fmoc group is removed with piperidine during chain elongation, while the Trt group is cleaved during final TFA-mediated resin cleavage. This allows lysine residues to be incorporated into peptide sequences without premature side chain reactions.

 Superior TFA Cleavage Performance

The trityl side-chain protecting group in Fmoc-Lys(Trt)-OH is more easily removed and scavenged during TFA cleavage than traditionally used Boc or t-butyl groups. This results in higher quality cleaved peptides by reducing t-butylated side products — a critical advantage for manufacturing high-purity therapeutic peptides.

 Versatile Building Block for Complex Peptides

Fmoc-Lys(Trt)-OH serves as a key building block for side-chain to side-chain cyclic peptides, oligolysine cores, multiantigenic peptides (MAPs), and template-assembled synthetic proteins (TASPs). The ε-amino group, after Trt deprotection, provides a handle for further functionalization — including cyclization, PEGylation, biotinylation, fluorophore attachment, or conjugation to targeting ligands.

 High Purity Grades for Every Application

Cosperpharm supplies Fmoc-Lys(Trt)-OH at multiple quality levels: standard grade (≥95% HPLC) for routine peptide synthesis and process development; and high-purity grade (≥99% to ≥99.8% chiral HPLC) for GMP peptide manufacturing and pharmaceutical applications.

 Essential for Peptide Therapeutics and Vaccines

Fmoc-Lys(Trt)-OH is indispensable for the synthesis of peptide therapeutics, peptide vaccines, antimicrobial peptides, and cell-penetrating peptides. Lysine-containing peptides have been extensively studied for applications ranging from oncology and infectious disease to metabolic disorders and immunology.

FAQ

Q1: What is Fmoc-Lys(Trt)-OH?

A: Fmoc-Lys(Trt)-OH (Nα-Fmoc-Nε-trityl-L-lysine, CAS 111061-54-2) is an orthogonally protected derivative of the essential amino acid L-lysine. The α-amino group is protected by the base-labile Fmoc group, and the ε-amino side chain is protected by the acid-labile trityl (Trt) group.

Q2: What is the difference between Fmoc-Lys(Trt)-OH and Fmoc-Lys(Boc)-OH?

A: Both are protected lysine derivatives, but they differ in the side-chain protecting group. Fmoc-Lys(Trt)-OH uses a trityl (Trt) group on the ε-amino side chain, which is cleaved by TFA during final resin cleavage. Fmoc-Lys(Boc)-OH uses a Boc group, which requires different deprotection conditions. The choice depends on the specific peptide sequence and synthesis strategy.

Product Quality Assurance

Cosperpharm has established a comprehensive quality assurance system for Fmoc-Lys(Trt)-OH that meets the rigorous expectations of both peptide synthesis and pharmaceutical research applications:

Thorough analytical characterization. Each batch undergoes multi-technique analytical release testing: HPLC purity verification, chiral HPLC for enantiomeric excess determination (≥99.8% ee for high-purity grade), appearance verification (white to off-white powder), melting point determination, water content (Karl Fischer), optical rotation, and where applicable, ¹H NMR and mass spectrometry confirmation of molecular identity.

Full batch traceability with retention samples. From raw material procurement through protection reactions, purification, drying, and final packaging, every step is fully documented and traceable. Each batch receives a unique lot number with sufficient retention samples maintained in accordance with Cosperpharm quality procedures.

Stability monitoring program. Cosperpharm conducts ongoing stability studies under recommended storage conditions (2–8 °C, protected from moisture and light). Stability summaries are updated regularly, with full data packages available to support customer quality requirements.

Documentation ready for regulatory submission. Every shipment includes a Certificate of Analysis (COA) with batch-specific purity and characterization data, a Material Safety Data Sheet (SDS), and customs documentation for international delivery. For customers preparing regulatory filings for peptide therapeutics, Cosperpharm provides custom quality agreements and stability data upon request.

Customer-initiated quality audits. Qualified customers are welcome to audit Cosperpharm's manufacturing, quality control, and documentation facilities. Please contact our regulatory team to schedule an audit.

Contact Us

Sourcing Fmoc-Lys(Trt)-OH for your peptide manufacturing or research program? Cosperpharm delivers the quality, documentation, and reliability you need. Get in touch with our team today — we're here to support your project from initial discovery through commercial production.