Fmoc-L-Lys(Mmt)-OH is an Fmoc-protected, free amino acid derivative of L-lysine bearing a side-chain guanidinium group masked as an Mmt (2,2,4,6,7-pentamethyl-dihydrobenzofuran-5-sulfonyl) protecting group, with the α-amino and α-carboxyl functionalities present on the lysine backbone. The molecule contains the Fmoc carbamate on the α-amino group and the Mmt sulfonamide on the ε-guanidinium side chain, providing chemoselectivity by suppressing side-chain reactivity during stepwise peptide assembly while retaining the backbone for coupling. In peptide synthesis workflows, it functions as a protected lysine building block for solid-phase or solution-phase preparation of peptides where controlled deprotection and subsequent formation of the lysine guanidinium functionality are required for downstream structure-activity or labeling studies.
CAT No: CP25413
CAS No:159857-60-0
Chemical Name:N-alpha-(9-Fluorenylmethyloxycarbonyl)-N-epsilon-4-methoxytrityl-L-lysine
Fmoc-L-Lys(Mmt)-OH is an Fmoc-protected L-lysine derivative in which the side-chain ε-amino group is masked as an Mmt (2,2,4,6,7-pentamethyl-dihydrobenzofuran-5-sulfonyl) carbamate, while the α-carboxyl group remains available for peptide coupling as a free acid. The molecule therefore presents a chiral α-center from L-lysine stereochemistry, an Fmoc group for solid-phase N-protection, and an orthogonally removable side-chain protecting group designed to tolerate standard peptide assembly conditions. The ε-amino functionality is rendered non-nucleophilic under typical coupling conditions, reducing undesired side reactions during chain elongation. The combination of Fmoc chemistry with Mmt side-chain protection makes the compound a practical chiral amino acid intermediate for constructing lysine-containing peptides and for downstream derivatization of the side chain after selective deprotection.
1. Peptide Synthesis
Fmoc-L-Lys(Mmt)-OH is used in peptide synthesis workflows where orthogonal protection of the lysine side chain supports controlled N- and side-chain chemistry during chain assembly. The Fmoc group enables stepwise N-terminal deprotection and coupling, while the Mmt-protected ε-amino group suppresses intramolecular side reactions such as branching or uncontrolled ε-functionalization during standard peptide coupling cycles. Lysine's primary side-chain amine, once unmasked by selective deprotection, can be converted into amide, urea, sulfonamide, or other nucleophile-derived motifs for peptide analog construction. The resulting lysine-containing peptide building blocks and intermediates are applicable to generating sequence-defined libraries and mechanistic peptide probes in amino acid chemistry and peptide science.
2. Side-Chain Functionalization
Fmoc-L-Lys(Mmt)-OH supports side-chain functionalization strategies that rely on the orthogonality between Fmoc removal and Mmt deprotection. The protected ε-amino group provides a stable handle for post-assembly modification, enabling introduction of charged groups, affinity tags, or reactive electrophiles onto the lysine side chain after peptide coupling. The free α-carboxyl functionality and the protected amine architecture facilitate conversion into peptide-bound or peptide-adjacent derivatives that can subsequently undergo acylation, alkylation, or conjugation chemistry. Downstream formation of functionalized lysine residues enables generation of peptidomimetics, receptor-binding motifs, and chemically defined molecular scaffolds for biochemical research and synthetic organic chemistry.
3. Bioconjugation Chemistry
Fmoc-L-Lys(Mmt)-OH is applicable to bioconjugation chemistry workflows that require lysine-compatible conjugation sites with controlled reactivity. The Mmt-protected ε-amino group can be kept inert during peptide assembly, then selectively revealed to generate a primary amine suitable for coupling to activated esters, isothiocyanates, aldehyde-derived linkers, or other electrophiles used in conjugate construction. The Fmoc-protected backbone also supports preparation of peptide conjugation partners with defined N-termini, which can influence labeling density and conjugate heterogeneity. Conjugate-ready lysine-containing intermediates derived from this protected amino acid can be employed for chemical biology studies, biomolecule labeling, and preparation of standardized materials for analytical investigations.
4. Process Chemistry Intermediate
Fmoc-L-Lys(Mmt)-OH is suitable for process chemistry intermediate preparation where protecting-group design and compatibility with peptide coupling conditions are central to manufacturable routes. The Fmoc group provides a robust N-protection strategy for controlled deprotection steps, while the Mmt side-chain protection helps manage chemoselectivity by preventing premature ε-amino participation during iterative synthesis. The compound's defined stereochemistry and stable protected functional groups can be leveraged to streamline downstream synthesis of lysine-containing peptide building blocks and peptidomimetic precursors at scale. Industrial chemical manufacturing routes can therefore incorporate this amino acid derivative to produce consistent intermediates for fine chemical synthesis and peptide-based specialty products.
5. Structure-Activity Relationship Studies
Fmoc-L-Lys(Mmt)-OH is used in structure-activity relationship studies where lysine side-chain placement and controlled derivatization are required to probe molecular recognition. The orthogonally protected ε-amino group allows systematic installation of side-chain modifications after peptide assembly, supporting comparison of analogs that differ in charge distribution, hydrogen-bonding capacity, or linker chemistry. The chiral L-lysine backbone stereochemistry contributes to maintaining conformational and binding-relevant geometry in peptide analogs. Lysine-containing peptide constructs prepared from this protected amino acid can serve as defined SAR reagents for fragment-based molecular design, peptide optimization campaigns, and mechanistic chemical biology investigations.
1. Myotropic activity of allatostatins in tenebrionid beetles
2. Cell-based adhesion assays for isolation of snake venom’s integrin antagonists
3. High fat diet and GLP-1 drugs induce pancreatic injury in mice
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