H-L-Asn-NH2*HCl

H-L-Asn-NH2*HCl is the hydrochloride salt of L-asparagine amide, featuring the canonical amino acid stereocenter at the alpha carbon and an unprotected primary amide side chain that remains chemically distinct from the alpha-amino functionality. The molecule contains a free amino group at the C-terminus (as an amidic functionality) and a protonated amine under hydrochloride conditions, which together shape its salt-form stability, aqueous handling, and coupling behavior. The side-chain carboxamide enables hydrogen-bonding interactions and can be selectively protected or transformed for amino acid derivatization and peptide chemistry. The compound's polar, strongly basic/acidic balance and well-defined stereochemistry make it a practical chiral building block and biochemical research intermediate for constructing amide-rich peptide and peptidomimetic motifs.

1. Peptide Synthesis

H-L-Asn-NH2*HCl supports peptide building workflows where the L-asparagine core must be incorporated as a C-terminal amide-forming residue, and the alpha-amino group and side-chain amide participate in standard peptide coupling logic after appropriate protection-state adjustment. The presence of the side-chain carboxamide and the terminal amino functionality can be leveraged to generate asparagine-containing peptide fragments and asparaginyl amide termini that require controlled chemoselectivity during coupling. Hydrochloride salt formation can improve handling and can be managed by base treatment prior to activation, enabling compatibility with common peptide coupling strategies for protected amino acid derivatives. Downstream, the resulting asparagine-containing peptides can serve as reference materials, scaffold components, or substrates for further functionalization in peptide science and chemical biology.

2. Chemical Biology Conjugation

H-L-Asn-NH2*HCl is suitable for chemical biology workflows that require incorporation of an asparagine-derived amide motif into conjugates, because the side-chain carboxamide provides a strong hydrogen-bonding handle for molecular recognition and linker design. The terminal amino functionality enables attachment strategies that can be tuned through protecting-group selection, allowing controlled formation of amide or urea-like linkages after derivatization of the amino groups. Salt-state protonation influences solubility and can be exploited to control reaction media during conjugation planning, especially in aqueous or mixed-solvent systems. The resulting asparagine-containing conjugates can be used to probe binding interactions, map recognition elements, or generate labeled biomolecular constructs for biochemical assays.

3. Unnatural Amino Acid Building

H-L-Asn-NH2*HCl functions as a chiral amino acid intermediate for preparing modified asparagine analogs, where the stereogenic alpha center and side-chain amide can be preserved while transforming other functional elements. The free terminal amino group and side-chain carboxamide can be selectively protected to enable orthogonal chemistry, supporting sequential derivatization such as side-chain activation, conversion to alternative amide/heteroatom patterns, or incorporation into peptidomimetic backbones. Hydrochloride salt handling provides a reproducible starting form for chiral synthetic intermediate preparation in fine chemical synthesis. Downstream derivatives generated from this scaffold can feed into unnatural amino acid incorporation studies, SAR-focused library synthesis, and peptide analog construction requiring defined stereochemistry.

4. Protected Amino Acid Chemistry

H-L-Asn-NH2*HCl is applicable to protected amino acid synthesis planning because its functional group set can be converted into N-protected and/or side-chain-protected forms that better withstand peptide coupling conditions. The side-chain carboxamide can be protected to modulate reactivity and to prevent undesired acylation during activation of the alpha-amino group, while the C-terminal amino functionality can be managed to target either amide formation or further extension. Hydrochloride salt behavior supports predictable deprotonation and protection-state transitions, which is relevant for manufacturing route design of peptide building blocks. Protected derivatives derived from this starting material can be used to generate asparagine-containing peptide building blocks with controlled chemoselectivity and stereochemical fidelity.

5. Analytical Research Standards

H-L-Asn-NH2*HCl can serve as an analytical reference material for amino acid and peptide method development, because its defined L-configuration and amide-rich functional groups produce characteristic signals in chromatographic and spectrometric workflows. The free amine and side-chain carboxamide enable method validation for quantitation of asparagine-containing species, including monitoring of deamidation-prone peptide fragments where asparagine stability is a key analytical parameter. Hydrochloride salt form improves reproducibility of sample preparation and can aid in establishing calibration standards for amino acid profiling and peptide composition analysis. Downstream, the compound supports analytical research intermediate preparation for method transfer, quality control of peptide syntheses, and characterization of asparagine-containing biomolecules.

1. A possible role of tachykinin-related peptide on an immune system activity of mealworm beetle, Tenebrio molitor L

2. Immune responses to peptides containing homocitrulline or citrulline in the DR4-transgenic mouse model of rheumatoid arthritis

3. Relatedness of antibodies to peptides containing homocitrulline or citrulline in patients with rheumatoid arthritis

4. Novel Peptide-Based PD1 Immunomodulators Demonstrate Efficacy in Infectious Disease Vaccines and Therapeutics

5. Crystal Structure of BamB from Pseudomonas aeruginosa and Functional Evaluation of Its Conserved Structural Features