Chemical Identity and Structure

(R)-2-((R)-2-Amino-3-phenylpropanamido)-3-phenylpropanoic acid is systematically named as the dipeptide D-Phe-D-Phe. It consists of two phenylalanine units, each bearing the R absolute configuration at the alpha carbon, joined by a peptide (amide) bond. The N-terminal residue carries a free primary amine, while the C-terminal residue retains a free carboxylic acid, making the molecule amphoteric. Both side chains are benzyl (–CH₂Ph) groups, which confer significant hydrophobic character and influence the compound's self-assembly propensity in solution.

The compound is the D-amino acid analogue of the well-studied L-Phe-L-Phe (H-Phe-Phe-OH) dipeptide. Its all-R stereochemistry distinguishes it from both the natural L,L diastereomer and the mixed L,D or D,L forms, making it a valuable tool for stereochemical structure–activity relationship (SAR) studies in peptide science.

Research Applications

As a stereochemically pure D-amino acid dipeptide, this compound finds application across several research domains:

• Peptide self-assembly studies: Diphenylalanine-based dipeptides are known to form nanostructures such as nanotubes, nanospheres, and hydrogels. The D,D enantiomer enables investigation of chirality-dependent assembly behaviour compared with the natural L,L form.
• Stereochemical SAR: Researchers use R,R vs S,S and mixed diastereomers to probe the role of backbone and side-chain chirality in receptor binding, enzyme inhibition, and supramolecular organisation.
• Peptide synthesis building blocks: The free amine and carboxylic acid groups allow further coupling reactions using standard solid-phase or solution-phase protocols (e.g., EDC/NHS, HATU-mediated coupling) to incorporate the D-Phe-D-Phe motif into longer sequences.
• Stability studies: D-amino acid-containing peptides are resistant to proteolytic degradation by most mammalian proteases, making D-Phe-D-Phe useful in studies of metabolic stability.

Handling, Storage, and Solubility

Storage: In the absence of specific certificate-of-analysis (CoA) instructions, dipeptides containing free amines and carboxylic acids are generally stored at –20 °C under dry, inert conditions, protected from light and moisture. Users should consult the product CoA received with their shipment for confirmed storage temperature and shelf life.

Solubility: The compound contains two ionisable groups (pKa values analogous to phenylalanine derivatives). It is expected to show limited solubility in pure water at neutral pH but improved solubility in dilute aqueous acid (protonates the amine), dilute aqueous base (deprotonates the carboxyl), DMSO, or DMF. Sonication or gentle warming may assist dissolution. Specific solubility data should be verified against the CoA or by in-house testing.

Handling: Standard laboratory precautions apply. Avoid inhalation of powder and contact with skin and eyes. Use appropriate PPE. Dispose of waste in accordance with local regulations.

Ordering and Quality Information

(R)-2-((R)-2-Amino-3-phenylpropanamido)-3-phenylpropanoic acid is available from Aladdin Scientific under SKU A709846. Each lot is supplied with a certificate of analysis confirming identity, purity, and other quality parameters. Researchers are encouraged to verify the stereochemical purity (e.g., chiral HPLC or optical rotation) if their application is sensitive to enantiomeric impurities.

For bulk quantities, custom synthesis enquiries, or specific purity grades, please contact Aladdin Scientific's technical sales team. Standard ordering can be completed through the Aladdin Scientific website or authorised distributors. Payment, shipping, and return policies are governed by Aladdin Scientific's standard terms and conditions.