H-Lys(Ac)-OH is a protected lysine derivative in which the ε-amino side chain is acylated with an acetyl group, while the α-amino and α-carboxyl groups remain present in the free form. The molecule contains an acetyl-protected ε-NH functionality that reduces side-chain nucleophilicity and can help control chemoselectivity relative to unprotected lysine during peptide-related coupling steps. H-Lys(Ac)-OH is used as an amino acid building block or intermediate for preparing lysine-containing peptides and peptide analogues where selective handling of the side-chain amine is required.
CAT No: CP27367
CAS No:692-04-6
Synonyms/Alias:N-epsilon-Acetyl-L-lysine;692-04-6;Nepsilon-Acetyl-L-lysine;N6-Acetyl-L-lysine;N-Epsilon-acetyllysine;(S)-6-Acetamido-2-aminohexanoicacid;Ne-Acetyllysine;N(6)-Acetyl-L-lysine;e-N-Acetyllysine;N(6)-ACETYLLYSINE;N-e-Acetyllysine;L-e-N-Acetyllysine;Ne-Acetyl-L-lysine;n6-acetyllysine;e-N-Acetyl-L-lysine;N-e-Acetyl-L-lysine;w-N-Acetyl-L-lysine;epsilon-N-Acetyllysine;epsilon-Acetyl-L-lysine;L-epsilon-N-Acetyllysine;omega-N-Acetyl-L-lysine;N(zeta)-acetyl-L-lysine;epsilon-N-acetyl-L-lysine;N(epsilon)-acetyl-L-lysine;UNII-470AD5VY1X
Lysine Nα-acetylated amino acid, H-Lys(Ac)-OH, is a chiral lysine derivative bearing a free carboxylic acid and an N-acetyl-protected ε-amino side chain precursor that maintains the canonical lysine stereocenter at the α-carbon. The molecule contains a primary amide (from the N-acetyl group) and a terminal carboxylic acid, enabling controlled reactivity in peptide coupling contexts while modulating basicity relative to unprotected lysine. The acetylated nitrogen reduces undesired side reactions during activation and coupling, and the remaining functional groups support downstream transformations such as conversion to activated esters or amide-forming intermediates. As an amino acid derivative and protected lysine building block, H-Lys(Ac)-OH can serve as a stereochemically defined intermediate for constructing lysine-containing peptides, conjugates, and synthetic scaffolds.
1. Protected Amino Acid Chemistry
H-Lys(Ac)-OH is applied in protected amino acid synthesis and peptide building block preparation where N-acetylation provides a stable amide handle for coupling chemistry while limiting side-chain overreactivity. The compound's free α-carboxyl group and N-acetylated amino functionality enable activation to carboxyl derivatives and subsequent formation of peptide bonds under standard peptide coupling conditions. The acetyl group can be retained for N-terminally capped peptide segments or removed in orthogonal deprotection strategies to regenerate an amine for further derivatization. Lysine stereochemical integrity at the α-carbon supports predictable incorporation into peptide sequences and chiral intermediate chains used in fine chemical synthesis.
2. Peptide Synthesis
H-Lys(Ac)-OH is suitable for peptide synthesis workflows that require a lysine residue with an N-acetyl cap, such as assembling peptide fragments for mapping, library construction, or sequence optimization. The amino acid backbone provides the α-amino/α-carboxyl functionality needed for amide bond formation, while the N-acetyl group influences coupling selectivity and suppresses competing reactions from the α-amino nitrogen. The ε-amino reactivity profile is governed by the specific lysine protection pattern implied by the N-acetylated form, supporting controlled side-chain handling during stepwise elongation. Downstream peptide products can be used as standards, reference materials, or intermediates for generating larger constructs in applied peptide science.
3. Chemical Biology Conjugation
H-Lys(Ac)-OH is employed in chemical biology and biomolecule modification strategies where lysine-containing linkers or amino acid-derived handles are required for conjugation chemistry. The presence of a carboxylic acid allows conversion to activated intermediates that can be coupled to amines on proteins, polymers, or affinity tags, while the N-acetyl group helps tune nucleophilicity and chemoselectivity during conjugation steps. The chiral lysine framework supports incorporation into peptide-like linkers used for controlled spacing, solubility modulation, and recognition element presentation. Resulting conjugates and linker building blocks can feed into downstream assays, imaging reagent development, and reagent characterization in biochemical research programs.
4. Process Chemistry Intermediate
H-Lys(Ac)-OH is relevant to process chemistry intermediate preparation for manufacturing routes that require a defined lysine derivative with reduced side reactions during activation and coupling operations. The N-acetylated amide functionality improves handling stability compared with more reactive unprotected amino forms, while the free carboxylic acid supports conversion into transportable activated forms for downstream synthesis. The stereochemical fidelity of the α-carbon reduces the risk of racemization in scalable sequences where chiral amino acid integrity is required. The compound can be incorporated into industrial fine chemical synthesis plans for producing protected lysine residues, peptide fragments, and amino acid-based intermediates used in multi-step manufacturing.
5. Analytical Reference Standards
H-Lys(Ac)-OH is applicable to analytical research and method development where amino acid derivative standards are needed to validate chromatographic separation, derivatization performance, and mass spectrometric identification of lysine-containing species. The defined acetylated nitrogen and free carboxylic acid produce characteristic chemical behavior under common analytical derivatization and ionization regimes, supporting reproducible signal generation. The stereochemically defined α-amino acid structure enables unambiguous comparison against related lysine derivatives used in peptide hydrolysis studies or degradation profiling. Analytical workflows can employ H-Lys(Ac)-OH as a reference for confirming identity and monitoring conversion in amino acid derivatization and peptide synthesis quality control.
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