Fmoc-AC4C-OH

Fmoc-AC4C-OH is an Fmoc-protected, chiral amino acid derivative featuring a fluorenylmethyloxycarbonyl (Fmoc) carbamate on the amino function and a carboxylic acid at the C-terminus, with a side-chain framework characteristic of the AC4C scaffold. The presence of the Fmoc group provides orthogonal N-protection compatible with standard base-labile deprotection strategies used in solid-phase peptide synthesis, while the free carboxyl group supports activation for amide bond formation. The stereogenic center within the AC4C residue enables stereochemically defined incorporation into peptides and peptide-like constructs, supporting downstream structure-function studies and chiral intermediate design. The compound's protected amine and unprotected acid combination makes it well suited as a peptide building block and as a controlled functionalized amino acid intermediate for further derivatization.

1. Peptide Synthesis

Fmoc-AC4C-OH is applied in peptide synthesis workflows where orthogonally protected amino acid building blocks are required for reliable chain elongation. The Fmoc-protected nitrogen and the free carboxylic acid enable iterative peptide coupling after Fmoc removal, allowing the AC4C residue to be incorporated at defined positions within a peptide sequence. The stereochemical integrity of the AC4C center supports the construction of stereodefined peptide analogs used for peptide coupling chemistry development and sequence-dependent property mapping. The resulting peptide products can be carried into downstream purification, fragment assembly, and analytical characterization as part of broader amino acid and peptide science.

2. Unnatural Amino Acid Incorporation

Fmoc-AC4C-OH is used as a chiral unnatural amino acid intermediate for introducing noncanonical side-chain features into peptides and peptidomimetics. The Fmoc-protected amine supports controlled incorporation under peptide synthesis conditions, while the carboxylic acid functionality allows conversion into activated species for amide bond formation with diverse nucleophiles. The defined stereochemistry of the AC4C scaffold can be leveraged to probe how specific stereochemical placement influences conformational preferences and molecular recognition in SAR studies. The compound thus serves as a practical input for generating unnatural amino acid-containing libraries and for preparing stereochemically resolved peptide analogs for biochemical research.

3. Side-Chain Functionalization

Fmoc-AC4C-OH is suitable for side-chain functionalization and downstream synthetic elaboration where the protected amino group prevents premature coupling during derivatization steps. The Fmoc carbamate acts as a stable handle that can be retained during selective transformations, while the carboxylic acid can be activated or converted into derivatives that serve as intermediates for further coupling, cyclization, or conjugation chemistry. The AC4C structural motif provides a defined scaffold for building peptidomimetic frameworks that incorporate functional groups through controlled synthetic sequences. The resulting functionalized amino acid derivatives can be used to generate molecular fragments for medicinal chemistry, chemical biology probes, and structured peptide analogs.

4. Chemical Biology Probes

Fmoc-AC4C-OH is applied in chemical biology research to construct labeled or reactive peptide constructs that require precise N-terminal protection management and stereodefined residue placement. The Fmoc protection strategy enables compatibility with peptide assembly protocols that later expose the amine for coupling to tags, linkers, or detection handles, while the carboxylic acid provides a consistent site for amide linkage within the probe architecture. The AC4C residue's stereochemical features can support reproducible probe behavior by maintaining defined 3D geometry in peptide-based recognition elements. The compound can therefore serve as a building block for generating peptide probes, affinity reagents, and structured molecular tools used in biochemical investigations.

5. Pharmaceutical Intermediate Preparation

Fmoc-AC4C-OH is relevant to pharmaceutical intermediate preparation and fine chemical synthesis where protected amino acid derivatives are manufactured for subsequent conversion into peptide-active intermediates. The Fmoc carbamate provides a controllable N-protection state that can be removed on demand during manufacturing sequences that assemble peptide fragments or generate defined peptide intermediates. The free carboxylic acid supports activation to form amide intermediates used in fragment coupling and in the preparation of stereochemically defined peptide building blocks for downstream synthesis. The compound's functional group pattern aligns with industrially scalable synthetic logic for producing protected amino acid inputs that feed peptide assembly, peptidomimetic construction, and process chemistry routes.

1. An Isolated TCR αβ Restricted by HLA-A* 02: 01/CT37 Peptide Redirecting CD8+ T Cells to Kill and Secrete IFN-γ in Response to Lung Adenocarcinoma Cell Lines

2. Immune responses to homocitrulline-and citrulline-containing peptides in rheumatoid arthritis

3. Crystal Structure of BamB from Pseudomonas aeruginosa and Functional Evaluation of Its Conserved Structural Features

4. Tachykinin-related peptides modulate immune-gene expression in the mealworm beetle Tenebrio molitor L

5. Myotropic activity and immunolocalization of selected neuropeptides of the burying beetle Nicrophorus vespilloides (Coleoptera: Silphidae)