Fmoc-L-Phe(4-NH2)-OH

Fmoc-L-Phe(4-NH2)-OH is an Fmoc-protected L-phenylalanine derivative bearing a para-amino substituent on the aromatic ring, providing a chiral amino acid backbone with an aniline-functionalized side chain. The molecule contains an Fmoc carbamate at the alpha-amino position and a free carboxylic acid, enabling controlled N-protection during peptide assembly while preserving C-terminal coupling capability. The side-chain primary amine is nucleophilic and can participate in selective derivatization, including acylation, sulfonylation, reductive amination, or orthogonally protected transformations to tune polarity and reactivity. The aromatic aniline motif and the stereogenic center together make the compound a practical chiral building block for peptide synthesis, amino acid modification chemistry, and downstream formation of functionalized peptidomimetics or conjugation-ready scaffolds.

1. Peptide Synthesis

Fmoc-L-Phe(4-NH2)-OH is used in peptide synthesis workflows where a protected alpha-amino group and a carboxylic acid enable standard amide bond formation at the peptide C-terminus. The para-amino phenyl side chain provides an additional functional handle that can be left protected or selectively unmasked depending on the coupling sequence, allowing incorporation of an aniline-bearing residue into linear peptides and protected peptide fragments. The Fmoc group supports orthogonal deprotection strategies under base-mediated conditions, while the chiral L-configuration maintains stereochemical fidelity at the residue level. The resulting peptide products can be further elaborated for charge modulation, crosslinking chemistry, or preparation of functional peptide analogs used in biochemical research and synthetic organic chemistry.

2. Side-Chain Functionalization

Fmoc-L-Phe(4-NH2)-OH serves as a platform for side-chain functionalization driven by the aromatic primary amine at the 4-position. The aniline functionality can undergo controlled protection and subsequent transformations, enabling synthesis of acylated or sulfonylated derivatives, formation of urea or amide linkages, or conversion to heteroatom-containing substituents that alter hydrogen-bonding patterns. The presence of the Fmoc-protected alpha-amino group and the free carboxyl group supports sequential chemistry where peptide coupling compatibility is maintained during side-chain derivatization planning. Downstream products include functionalized amino acid intermediates and peptidomimetic building blocks used to generate structure-diverse libraries for molecular design and SAR studies.

3. Chemical Biology Probes

Fmoc-L-Phe(4-NH2)-OH is suitable for chemical biology applications requiring an amino acid residue that can be incorporated into peptides or peptide-like constructs and later converted into reactive or labeled forms. The para-amino group can enable conjugation chemistries such as acylation with activated esters, formation of stable linkages to electrophilic tags, or preparation of affinity handles for immobilization strategies. The Fmoc-protected backbone supports stepwise assembly of labeled or capture-ready peptide reagents while maintaining the stereochemical integrity of the L-phenylalanine core. The resulting conjugation-ready intermediates can be applied to biomolecule modification, probe generation, and analytical reagent construction where controlled functional-group placement is required.

4. Peptidomimetics And SAR

Fmoc-L-Phe(4-NH2)-OH can be employed in peptidomimetic construction and SAR-focused synthesis where an aniline-bearing aromatic side chain contributes to aromatic interactions and tunable hydrogen-bonding capacity. The alpha-carboxylic acid and Fmoc carbamate allow integration into protected building-block routes that support iterative assembly of peptide analogs and scaffold fragments. The para-amino substituent can be leveraged to introduce additional pharmacophore elements through derivatization, enabling systematic variation of electronic character and polarity while retaining the chiral center. Downstream use includes preparation of structure-defined analog series for medicinal chemistry research, fragment-based molecular design, and refinement of structure-function relationships in applied molecular scaffold development.

5. Pharmaceutical Intermediate Preparation

Fmoc-L-Phe(4-NH2)-OH is applicable to pharmaceutical intermediate preparation in manufacturing-aligned synthetic sequences that require a chiral, N-protected amino acid with a reactive side-chain amine. The Fmoc-protected alpha-amino group supports controlled handling during multi-step synthesis, while the free carboxylic acid enables coupling or conversion to activated derivatives for subsequent assembly into larger intermediates. The para-amino functionality can be managed through protection/deprotection logic to fit process constraints and to minimize side reactions during scale-up chemistry. The compound can therefore serve as a defined stereochemical input for producing protected amino acid derivatives, peptide-like intermediates, and functionalized building blocks used in fine chemical synthesis and specialty chemical production pipelines.

1. A possible role of tachykinin-related peptide on an immune system activity of mealworm beetle, Tenebrio molitor L

2. An interdomain binding site on HIV-1 Nef interacts with PACS-1 and PACS-2 on endosomes to down-regulate MHC-I

3. Autoinhibition and phosphorylation-induced activation of phospholipase C-γ isozymes

4. Low bone turnover and low BMD in Down syndrome: effect of intermittent PTH treatment

5. Emu oil in combination with other active ingredients for treating skin imperfections