DL-homoleucine is a free, non-proteinogenic amino acid in the leucine family, featuring an aliphatic side chain extended by one methylene relative to leucine and bearing a branched hydrocarbon functionality. The molecule contains both an amino group and a carboxyl group, and the "DL" designation indicates a racemic mixture of stereoisomers at the α-carbon, with the side chain remaining hydrophobic and conformationally flexible. As a substrate for peptide and amino acid derivative synthesis, it can be incorporated into modified peptide structures in structure-activity studies and used as a building block for analytical standards or labeling reagents where a longer branched aliphatic side chain is required.
CAT No: CP06503
DL-homoleucine contains a branched isobutyl-like side chain extended by one methylene relative to leucine, providing a hydrophobic, conformationally informative alkyl framework attached to an amino acid backbone. The molecule bears a primary amino group and a carboxylic acid, and the DL designation indicates a racemic mixture at the α-carbon, which affects stereochemical outcomes in peptide coupling and downstream chiral recognition. Relative reactivity is governed by the carboxyl group for amide bond formation and by the amino group for N-functionalization, while the side-chain alkyl functionality supports hydrophobic interactions and can be derivatized to introduce additional steric and conformational constraints. As a chiral amino acid intermediate precursor in racemic form, DL-homoleucine is commonly handled through temporary protection of the amine and/or activation of the acid to enable controlled synthesis of peptide fragments and functionalized amino acid derivatives.
1. Peptide Coupling
DL-homoleucine serves in peptide synthesis and fragment assembly where an extended hydrophobic side chain is required to tune steric bulk and conformational preferences. The amino acid backbone supports standard peptide coupling chemistry after conversion to an amine-protected or activated carboxyl derivative, with racemic stereochemistry enabling preparation of mixed stereochemical peptide analogs for method development or scaffold screening. The carboxyl group participates in formation of amide linkages, while the side-chain alkyl framework can influence solubility and aggregation behavior in longer sequences. Downstream, DL-homoleucine-incorporated peptides can be used to generate libraries of hydrophobic analogs for SAR studies and to prepare peptide standards for analytical method evaluation.
2. Amino Acid Derivatization
DL-homoleucine is suitable for amino acid derivatization workflows that convert the free amino and carboxylic acid into protected intermediates, activated esters, or functionalized side-chain analogs. The α-amino and α-carboxyl groups can be selectively masked using common protection strategies, enabling orthogonal transformations that support stepwise synthesis of N-protected amino acid derivatives and C-terminal modifications. Racemic stereochemistry can be exploited when the target application tolerates stereochemical mixtures, such as preparing racemic intermediates for screening or for downstream resolution steps. Functionalized derivatives derived from DL-homoleucine can then feed into peptidomimetic construction, polymerizable monomer synthesis, or further synthetic elaboration toward specialty chemical building blocks.
3. Process Chemistry Intermediate
DL-homoleucine can be applied as a process chemistry intermediate for manufacturing routes that require a racemic hydrophobic amino acid feedstock for protected amino acid synthesis and downstream fine chemical production. The stable amino acid functional group pattern enables conversion into activated forms (for coupling) and into protected forms (for controlled reaction sequences) using scalable protection and activation logic. The extended branched side chain can be leveraged to introduce hydrophobic character into intermediates used for peptide-like materials, chiral auxiliary precursors, or substrate scaffolds in chemical manufacturing. Industrially relevant planning can use the racemate to simplify sourcing and handling, with later stereochemical adjustment performed only if a downstream specification requires enantiopure material.
4. Peptidomimetics And SAR
DL-homoleucine supports peptidomimetic construction and structure-activity relationship studies where hydrophobic side-chain length and branching are used to modulate binding pocket fit and conformational sampling. The amino acid backbone provides a recognizable template for incorporation into amide-linked analogs, while the racemic α-center enables generation of stereochemical variants that can be compared in SAR workflows without requiring immediate resolution. Side-chain hydrophobicity can be translated into analogs such as constrained turn mimetics or backbone-modified scaffolds after appropriate protection and functional group transformation. Downstream derivatives prepared from DL-homoleucine can be used to generate chemical libraries for SAR mapping, fragment-to-lead exploration, and analytical characterization of structure-dependent behavior.
5. Analytical Standards
DL-homoleucine can be utilized in analytical research as a reference material for amino acid profiling, derivatization method development, and chromatographic or spectrometric calibration. The presence of both amino and carboxyl functional groups enables conversion to common derivatized forms used in amino acid analysis, while racemic composition provides a defined benchmark for assessing stereochemical separation performance. The extended branched side chain helps distinguish it from closely related amino acids such as leucine, supporting method specificity in complex matrices. Downstream, DL-homoleucine-derived standards and internal references can improve reliability of quantitation in studies involving amino acid metabolism, peptide hydrolysates, or synthetic intermediate monitoring.
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