D-Tryptophan

Technical Specifications

Product Description & Scientific Applications

D-Tryptophan ((2R)-2-amino-3-(1H-indol-3-yl)propanoic acid, (R)-tryptophan, D-Trp) is the non-proteinogenic D-enantiomer of the aromatic indole amino acid tryptophan. It is supplied as a white to pale yellow crystalline powder with a melting/decomposition range near 282–285 °C and a positive specific rotation around +31° in water, consistent with the D/R configuration. The compound is sparingly soluble in water (~11 g/L at 20 °C), soluble in dilute acid, alkali hydroxide solution, hot alcohol, and DMSO, and essentially insoluble in chloroform. Its indole side chain provides near-UV absorbance around 280 nm and intrinsic fluorescence emission near 350 nm, making D-Tryptophan useful as a chiral indole amino-acid reference, peptide-synthesis building block, and substrate or probe in D-amino-acid metabolism studies.

Applications:

• D-peptide and antimicrobial-peptide synthesis: Incorporated into synthetic research peptides as a hydrophobic aromatic D-residue where the indole side chain is required but proteolytic stability, stereochemical inversion, or altered membrane interaction is desired. D-Trp is useful in mirror-image peptide design, partial D-substituted peptides, cyclic peptide analogues, and Trp-rich antimicrobial or amphipathic peptide scaffolds studied for membrane binding, interfacial anchoring, and structure–activity relationships.
• Spectroscopic and chiral analytical reference: The indole chromophore of D-Tryptophan absorbs near 280 nm and gives environment-sensitive fluorescence around 340–360 nm, supporting use as an enantiomeric reference in fluorescence spectroscopy, circular dichroism, chiral HPLC, and capillary electrophoresis methods that distinguish D- from L-tryptophan and resolve indole-containing amino-acid or peptide mixtures.
• D-amino acid oxidase and kynurenine-pathway metabolism studies: D-Tryptophan is a substrate of D-amino acid oxidase (DAAO), the FAD-dependent flavoenzyme that catalyses stereoselective oxidative deamination of D-amino acids to the corresponding α-keto acids, hydrogen peroxide, and ammonia. In mammalian metabolism studies, D-Tryptophan is converted in brain and peripheral tissues into kynurenine-pathway metabolites including D-kynurenine, L-kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid, with DAAO involvement confirmed experimentally. This supports its use in studies of DAAO substrate specificity, D-amino-acid metabolism, and stereoselective indole catabolism.
• Biofilm and microbial-community research: Used in bacterial biofilm studies investigating D-amino-acid-mediated inhibition, dispersal, and cell-wall or matrix regulation. D-Tryptophan is reported both as a component of D-amino-acid mixtures that disperse established biofilms and as an individual D-amino acid affecting attachment and biofilm formation in Pseudomonas and Staphylococcus systems.

Shipping Destinations

• EU & UK: Priority delivery, 2–5 business days.
• United States (DDP): 3–7 business days, duties and taxes prepaid.
• EFTA Countries (DDP): 3–7 business days, duties and taxes prepaid.
• Worldwide: 7–14 business days, selected locations.