4-Phenyl-DL-Phenylalanine is a non-proteinogenic, structurally modified amino acid derivative featuring an α-amino and a carboxyl group on the same carbon framework as phenylalanine, with an additional phenyl substituent at the 4-position of the side chain. The molecule is provided as a DL mixture, corresponding to both stereochemical configurations at the α-carbon, and its side chain bears a hydrophobic, aromatic functionality that can engage in π-interactions while remaining chemically distinct from standard phenylalanine. In chemical biology and peptide chemistry, this aromatic-rich analogue is used as a precursor for preparing substituted amino acid building blocks and for incorporating atypical aromatic side-chain environments into peptide or labeling workflows to support structure-activity studies and analytical method development.
CAT No: CP16303
CAS No:76985-08-5
Synonyms/Alias:76985-08-5;4-Phenyl-DL-Phenylalanine;3-([1,1'-Biphenyl]-4-yl)-2-aminopropanoicacid;DL-4-PHENYL-PHE-OH;2-amino-3-(4-phenylphenyl)propanoicacid;2-AMINO-3-(4-BIPHENYLYL)PROPANOICACID;2-AMINO-3-BIPHENYL-4-YL-PROPIONICACID;4-Phenyl-L-phenyalanine;D-4,4'-Biphenylalanine;L-4,4'-Biphenylalanine;DL-BIPHENYLALANINE;(S)-2-AMINO-3-BIPHENYL-4-YL-PROPIONICACID;SCHEMBL93494;MolPort-003-795-068;6226AJ;AKOS000170983;AKOS022184250;AB14606;AM83473;VA50437;VA50438;VZ31222;AK-87845;AN-36846;KB-40271
4-Phenyl-DL-Phenylalanine is a non-natural, DL-racemate amino acid derivative bearing a benzyl side chain and an additional phenyl substituent, providing a sterically and electronically rich aromatic environment. As an unprotected amino acid building block, it is commonly used in synthetic peptide and peptidomimetic research where aromatic bulk and conformational effects are leveraged for structure-activity relationship studies. Its racemic (DL) stereochemistry supports exploratory design workflows that screen stereochemical influence on downstream binding, stability, or material interactions.
1. Peptidomimetic Building Blocks
4-Phenyl-DL-Phenylalanine is frequently selected as an aromatic amino acid building block for peptidomimetic synthesis and SAR-focused library construction, where introducing a bulky, hydrophobic phenyl-rich side chain helps probe how sterics and π-interactions influence target engagement in chemical biology and medicinal chemistry programs. Researchers use this derivative to generate analog series that systematically vary aromatic content while maintaining an amino-acid-derived backbone handle for subsequent coupling into short peptides, constrained mimetics, or hybrid scaffolds. The DL stereochemical mixture is particularly useful during early-stage screening, when the goal is to identify whether aromatic substitution drives measurable trends before committing to stereodefined optimization.
2. Structure-Activity Relationship Probes
4-Phenyl-DL-Phenylalanine supports structure-activity relationship studies aimed at mapping the contribution of aromatic substitution patterns to physicochemical and interaction properties of bioactive peptide-like molecules. Medicinal chemistry groups incorporate this building block into analogs to evaluate how additional phenyl substitution affects conformational preferences, hydrophobic surface area, and aromatic stacking propensity relative to simpler phenylalanine-based motifs. Because the material is provided as a racemate, it is often used for rapid generation of diverse analogs to identify whether stereochemical resolution is warranted in later optimization stages, while still enabling direct comparison across a set of related structures.
3. Aromatic-Rich Peptide Synthesis
4-Phenyl-DL-Phenylalanine is used in custom peptide synthesis workflows to introduce an aromatic-rich residue that can enhance hydrophobic character and shape local microenvironments within peptide sequences. Peptide chemistry teams employ this building block to prepare short peptides, test constructs, and fragment libraries where aromatic side-chain volume and phenyl-phenyl interactions are expected to influence folding tendency, aggregation propensity, or binding-site complementarity. The unprotected amino acid form is typically handled as a defined coupling component in downstream peptide assembly, enabling incorporation into research-grade sequences for binding assays, stability comparisons, and material-interaction studies.
4. Chiral Resolution Screening
4-Phenyl-DL-Phenylalanine is also used as a practical starting material for stereochemical exploration and chiral resolution workflows in research settings. Synthetic and analytical chemistry teams often begin with the DL mixture to assess whether stereochemistry materially impacts downstream properties of interest, such as chromatographic behavior, derivatization response, or performance trends in peptide-like systems. The racemic form simplifies early experimental throughput, allowing researchers to screen stereochemical sensitivity before moving to stereochemically defined analogs for more detailed characterization and follow-on development.
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