Fmoc-Lys(Mmt)-OH

Fmoc-Lys(Mmt)-OH is an excellent derivative for the synthesis by Fmoc SPPS of branched peptides and peptides modified at the lysine side‑chain, and for the construction of templates and multifunctionalized resins for combinatorial synthesis. The side‑chain Mmt group on Fmoc-Lys(Mmt)-OH can be selectively removed under exceptionally mild conditions — including 1% TFA in DCM, DCM/HFIP/TFE/TES (6.5:2:1:0.5), or AcOH/TFE/DCM (1:2:7) — allowing Mmt removal without affecting other acid‑labile protecting groups such as Boc, Trt, Pbf, or the Wang resin linkage. Fmoc-Lys(Mmt)-OH is widely used for preparing side‑chain to side‑chain cyclic peptides, constructing branched peptide cores for multiple antigen peptides (MAPs), and generating immobilized peptide templates for proteomics and drug discovery applications.

Product Parameters

Synthetic Route

Fmoc-Lys(Mmt)-OH is synthesized from L‑lysine through an orthogonal protection strategy. A highly efficient method involves copper complexation: the intermediate H‑Lys(Mmt)-OH is first complexed with a copper salt, purified, and then de‑complexed to liberate the free ε‑amine. The α‑amino group is then protected with the Fmoc group under standard conditions. The copper complexation approach effectively shortens the synthetic route while avoiding the use of silicon‑containing compounds, offering simplified and efficient production. Alternatively, the compound can be prepared by direct protection of the ε‑amine with Mmt‑Cl, followed by Fmoc protection of the α‑amino group. The final product is purified by recrystallization and characterized by HPLC, TLC, optical rotation, and NMR.

Storage Conditions

Store Fmoc-Lys(Mmt)-OH in a tightly sealed container at 2–8 °C, protected from light and moisture. For long‑term storage (>12 months), store at –20 °C under inert atmosphere. The Mmt group is highly acid‑sensitive — avoid exposure to strong acids, and ensure storage containers are sealed to prevent moisture ingress that could lead to localized acidic degradation.

Shelf life: 3 years when stored at –20 °C in a sealed container under inert atmosphere; 2 years when stored at 4 °C. Stability summaries are available upon request to support regulatory filings.

Handling precautions: Use in a fume hood. Wear chemical‑resistant gloves, safety goggles, and a lab coat. Avoid generating dust. Do not eat, drink or smoke in work areas. After handling, wash hands thoroughly. Refer to the Safety Data Sheet (SDS) for complete safety information.

Application Scenarios

1. Branched Peptide (MAP) Synthesis

Fmoc-Lys(Mmt)-OH is the essential building block for constructing multiple antigen peptides (MAPs), where successive rounds of Mmt deprotection and lysine coupling generate dendritic cores presenting multiple peptide antigen copies for immunological studies.

2. Side‑Chain to Side‑Chain Cyclic Peptides

The orthogonal Mmt protection enables the synthesis of cyclic peptides via cyclization between the ε‑amine (after Mmt removal) and a side‑chain carboxylate or other functional group, creating conformationally constrained macrocycles with enhanced metabolic stability and target affinity.

3. Multifunctionalized Resin Construction

Fmoc-Lys(Mmt)-OH is used to create templates and multifunctionalized resins for combinatorial synthesis, where the Mmt group serves as a temporary handle for introducing orthogonal functional groups at specific positions.

4. Peptide Immobilization for Proteomics

After SPPS assembly, selective Mmt removal allows for site‑specific immobilization of peptides onto solid supports or magnetic beads for affinity capture experiments, pull‑down assays, and proteomics workflows.

5. Biotin or Fluorescent Labeling

The Mmt group provides a temporary mask for the ε‑amine, which after removal serves as a site for introducing biotin, FITC, Cy5, or other labels for detection, imaging, and purification applications.

6. Antifungal Peptoid Development

Fmoc-Lys(Mmt)-OH has been successfully employed in the synthesis of peptoid derivatives with antifungal activity against Cryptococcus neoformans, demonstrating its utility in developing new antimicrobial agents.

7. Peptide–Drug Conjugate (PDC) Synthesis

The orthogonal Mmt protection allows for differential functionalization strategies, enabling the attachment of cytotoxic payloads to the ε‑amine while preserving the peptide targeting sequence intact.

8. Solid‑Phase Synthesis of Peptide Libraries

In combinatorial chemistry, Fmoc-Lys(Mmt)-OH enables the generation of diversity at the lysine side chain, facilitating the construction of large peptide libraries for high‑throughput screening against biological targets.

9. Protease‑Resistant Peptide Therapeutics

The branched and cyclic architectures enabled by Fmoc-Lys(Mmt)-OH can confer enhanced proteolytic stability to therapeutic peptides, extending their in vivo half‑life.

10. Analytical Method Development & Validation

Fmoc-Lys(Mmt)-OH serves as a reference standard for developing and validating HPLC and UPLC methods for complex peptide synthesis monitoring, impurity profiling in branching strategies, and quality control of peptide therapeutics.

11. Process Development & Scale‑Up

Pharmaceutical process chemists use Fmoc-Lys(Mmt)-OH for optimizing Mmt deprotection conditions, investigating orthogonal protection strategies, and developing scalable commercial manufacturing routes for branched and cyclic peptide therapeutics.

Contact Us

Ready to advance your branched or cyclic peptide synthesis with Fmoc-Lys(Mmt)-OH from a supplier you can trust? Cosperpharm is here to help. Contact our sales team for pricing, COA requests, or technical consultation — we look forward to supporting your peptide chemistry needs.