D-Homocysteine is a sulfur-containing, non-proteinogenic amino acid derivative classified as a thioether amino acid, featuring a three-carbon side chain terminating in a thiol group and a carboxylic acid and primary amino group on the alpha carbon. The molecule bears a free thiol that can undergo oxidation or participate in thiol-disulfide exchange chemistry, and its stereochemistry is specified as the D-form at the alpha carbon. D-Homocysteine is used as a chemical building block and substrate analogue in peptide and thioether/thio-disulfide related synthesis, as well as in biochemical and analytical studies that require a defined sulfur-containing amino acid scaffold for labeling, conjugation, or structure-activity investigations.
CAT No: CP06303
D-Homocysteine is the D-configured amino acid analog of cysteine, featuring a chiral α-carbon bearing an amino group and a carboxylic acid, along with a side chain that terminates in a thiol (-SH). The molecule's stereochemistry at the α-center governs its behavior in stereoselective derivatization, chiral resolution workflows, and enzyme-recognition studies, while the sulfur functionality enables redox chemistry and nucleophilic participation in thioether and disulfide formation. D-Homocysteine typically exists in equilibrium between protonation states of the carboxyl and thiol groups, which influences solubility, coupling efficiency, and compatibility with protecting-group strategies used in amino acid and peptide synthesis. As a chiral amino acid intermediate, it can be converted into protected thiol derivatives, activated esters, or protected amino acid building blocks for downstream sulfur-containing scaffold construction.
1. Thiol Derivatization Chemistry
D-Homocysteine is employed in chemical synthesis workflows that require controlled thiol functionalization, where the side-chain -SH group can be converted into thioethers, disulfides, or sulfenylating intermediates for stepwise molecular assembly. D-Homocysteine's amino acid backbone supports selective protection of the amine and carboxyl group, enabling orthogonal strategies such as thiol protection for later deprotection while maintaining the stereochemical integrity of the D-center. Thiol reactivity facilitates downstream conjugation to electrophiles used for creating sulfur-containing motifs in research-grade intermediates and fine chemical targets. D-Homocysteine-derived sulfur functionalities can then be carried into peptidomimetic fragments, ligand scaffolds, or reactive handles for subsequent coupling chemistry, aligning amino acid derivatization with sulfur chemistry.
2. Protected Amino Acid Building Blocks
D-Homocysteine is suitable for preparing protected amino acid derivatives used in peptide building block preparation and amino acid ester synthesis, where the amino and carboxyl functionalities can be masked to control chemoselectivity during coupling. The thiol group can be protected as a thioether or protected thiol form to prevent side reactions during activation of the carboxyl group and peptide coupling steps, while the D-configuration supports stereochemically defined incorporation into modified sequences. Protected D-homocysteine derivatives can be used to generate C-terminal or side-chain-functionalized intermediates that participate in standard peptide coupling chemistry after deprotection. Downstream, these derivatives serve as intermediates for sulfur-containing peptide analogs and chiral amino acid incorporation strategies in synthetic organic chemistry and biochemical research.
3. Peptide Coupling And Analog Design
D-Homocysteine is applied in peptide synthesis and peptidomimetic construction where a stereodefined, sulfur-bearing amino acid residue provides a handle for redox-responsive or thioether-based structural features. The presence of both an α-amino group and a carboxylic acid enables conversion into activated forms for amide bond formation, while thiol functionality can be preserved or transformed into stable thioether/disulfide patterns depending on the target analog. D-Homocysteine's chirality supports the design of stereochemically constrained peptide analogs for structure-activity relationship studies and molecular recognition investigations. Resulting D-homocysteine-containing peptides and analogs can be used as research tools for probing how sulfur chemistry and stereochemistry influence binding, stability, and conformational behavior in amino acid science.
4. Chemical Biology And Bioconjugation
D-Homocysteine is utilized in chemical biology workflows that require thiol-based conjugation chemistry, leveraging the side-chain -SH group as a nucleophile or redox-active moiety for attachment to maleimide, haloacetamide, or disulfide-forming electrophiles. The amino acid backbone supports controlled derivatization into conjugatable intermediates while maintaining a D-configured stereocenter for studies involving stereochemical effects on biomolecular interactions. Thiol chemistry enables generation of thioether-linked conjugates and disulfide-linked constructs that can be used to modulate stability and release behavior in labeling experiments. D-Homocysteine-derived conjugates can function as biochemical research intermediates for constructing labeled peptides, sulfur-functional probes, and stereochemically defined biomolecule modification reagents.
5. Process Chemistry Intermediate
D-Homocysteine is relevant to process chemistry and specialty chemical production as a chiral amino acid intermediate for manufacturing routes that require sulfur-containing building blocks with defined stereochemistry. The thiol group enables conversion into protected forms that can be handled under conditions compatible with amide coupling, esterification, or multistep synthesis, while the amino acid functional groups support activation and downstream transformation into higher-value derivatives. D-Homocysteine can be incorporated into synthetic sequences that produce sulfur-bearing intermediates for fine chemical synthesis, including thioether and disulfide-containing scaffolds used across research and industrial manufacturing. Stereochemical fidelity at the D-center supports consistent quality in chiral intermediate preparation and enables reproducible downstream derivatization in amino acid chemistry supply chains.
6. Analytical Standards Development
D-Homocysteine is used in analytical research for developing reference materials and calibration standards that distinguish stereochemical forms of sulfur-containing amino acids. The combination of an α-amino acid framework and a thiol side chain supports derivatization approaches used to enhance detectability in chromatographic and spectrometric workflows, including thiol-specific tagging and controlled oxidation states for reproducible signal generation. D-Homocysteine's defined D-configuration enables stereospecific method validation and impurity profiling when monitoring amino acid derivatization, protection strategies, or peptide hydrolysis products. D-Homocysteine-derived standards and derivatives can therefore support routine analytical method development and quality-relevant characterization in amino acid manufacturing and biochemical research intermediate handling.
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