H-L-4Pal-OH*HCl

H-L-4Pal-OH*HCl is the hydrochloride salt of L-4-(4-pyridyl)alanine, an amino acid derivative featuring a stereogenic α-carbon in the L-configuration, a free primary amino group as the protonated chloride salt, and a carboxylic acid suitable for amide formation. The side chain contains a pyridine nitrogen that can participate in hydrogen bonding and metal coordination, enabling distinct recognition behavior in peptide and small-molecule contexts. The salt form improves handling of the amino acid for coupling chemistry while preserving the underlying functional-group pattern required for protected amino acid synthesis and downstream transformations. The combination of an amino acid backbone with a heteroaromatic side chain supports peptide coupling, selective functionalization of the pyridine, and construction of chiral intermediates for synthetic organic chemistry and biochemical research.

1. Peptide Synthesis

H-L-4Pal-OH*HCl is applied in peptide building workflows where an amino acid with an L-configured α-center is required for stereochemically defined incorporation. The protonated amino functionality and carboxylic acid enable conversion into activated coupling partners, while the pyridine-containing side chain remains compatible with standard peptide coupling conditions and can be carried through as a stable heteroaromatic motif. Salt-state handling supports preparation of peptide coupling feeds and can be integrated with orthogonal protection strategies for N- and side-chain chemistry. The resulting peptide products can serve as substrates for biochemical assays, as reference standards for analytical method development, or as scaffold elements in peptidomimetic design.

2. Side-Chain Functionalization

H-L-4Pal-OH*HCl supports side-chain functionalization strategies that exploit the pyridine nitrogen for controlled derivatization and coordination chemistry. The heteroaromatic ring can undergo transformations such as quaternization, metal-complex formation, or directed conjugation after appropriate protection of the amino acid functionality during intermediate synthesis. The carboxylic acid and amino group pattern allows preparation of derivatives where the pyridine serves as a handle for molecular recognition, labeling, or fragment attachment in synthetic sequences. Downstream utility includes generating functionalized amino acid analogs for chemical biology probes, building blocks for SAR-focused libraries, and intermediates that can be carried into larger heterocycle-containing frameworks.

3. Chiral Building Block Development

H-L-4Pal-OH*HCl functions as a chiral amino acid intermediate for stereoselective synthesis of nitrogen-containing motifs and heteroaromatic amino acid derivatives. The L-stereocenter provides defined stereochemical information for constructing dipeptides, peptidomimetics, and chiral ligands where the spatial arrangement around the α-carbon influences conformational preferences. The amino acid backbone can be protected and deprotected in a controlled manner to support sequential chemistry, while the pyridine side chain can be retained or further elaborated depending on the target structure. Industrially, this stereodefined intermediate can be used in fine chemical synthesis and process chemistry routes that require reproducible chiral feedstocks for downstream specialty molecules.

4. Chemical Biology Probes

H-L-4Pal-OH*HCl is suitable for chemical biology research where heteroaromatic amino acid residues enable specific interactions with proteins, nucleic acids, or metal-dependent binding sites. The pyridine side chain can act as a recognition element that participates in coordination and hydrogen-bonding networks, while the amino acid core supports incorporation into peptides or peptide-like constructs for probing molecular interactions. Salt-state amino acid handling can facilitate preparation of conjugation-ready intermediates after N-protection and carboxyl activation steps, enabling controlled labeling or immobilization strategies. Generated probe molecules can be used for binding studies, competitive assays, and mechanistic investigations that rely on defined stereochemistry and a functional heteroaromatic side chain.

5. Pharmaceutical Intermediate Preparation

H-L-4Pal-OH*HCl is relevant to pharmaceutical intermediate preparation where chiral amino acid derivatives bearing heteroaromatic handles are incorporated into medicinal chemistry scaffolds. The protected amino acid chemistry compatible functional groups allow conversion into N-protected derivatives and activated carboxylic acid forms used in amide bond construction during lead optimization. The pyridine nitrogen provides a chemically tunable site for salt formation, hydrogen-bond acceptor behavior, and coordination-controlled conformational effects in larger molecules. Downstream manufacturing routes can employ this amino acid as a stereochemically defined input for fine chemical synthesis, enabling consistent generation of heteroaromatic-containing intermediates used in compound library production and process-scale synthesis planning.

6. Analytical Research Standards

H-L-4Pal-OH*HCl can be utilized in analytical research as a reference material for amino acid profiling, stereochemical verification, and method qualification involving pyridine-containing amino acid derivatives. The defined L-configuration and presence of both amino and carboxylic acid functional groups support robust detection in chromatographic and mass spectrometric workflows after derivatization into common analytical forms. The hydrochloride salt state can improve reproducibility of sample preparation for calibration and comparative quantitation, while the pyridine side chain provides a distinctive fragmentation and retention behavior relative to non-heteroaromatic analogs. Analytical standards derived from this compound can also support quality control of peptide building block preparation and verification of amino acid incorporation in synthetic peptide chemistry.

1. Investigating Potential Interactions Between Neurohypophyseal Peptides, their Drug Analogs, and Coagulation Factor VIII

2. Peptides as Active Ingredients: A Challenge for Cosmeceutical Industry

3. TMEM16F and dynamins control expansive plasma membrane reservoirs

4. Constitutive and inflammation-dependent antimicrobial peptides produced by epithelium are differentially processed and inactivated by the commensal Finegoldia magna and the pathogen Streptococcus pyogenes

5. Extended exenatide administration enhances lipid metabolism and exacerbates pancreatic injury in mice on a high fat, high carbohydrate diet