H-Cys(Dpm)-OH

H-Cys(Dpm)-OH is a cysteine derivative presented as the free amino acid with the thiol masked by a Dpm (diphenylmethyl) protecting group, yielding a chiral, sulfur-containing building block suitable for peptide and chemical modification workflows. The molecule retains the amino and carboxylic acid functionality for coupling chemistry while the side-chain thiol is rendered less nucleophilic and more compatible with orthogonal protection schemes during multi-step synthesis. The Dpm group provides a stable thioether-protected handle that can be selectively removed under conditions tailored for sulfur deprotection, enabling downstream formation of native cysteine thiols or thiol-reactive intermediates. The stereogenic center at the cysteine backbone supports stereochemically defined incorporation into peptides and chiral synthetic sequences, making H-Cys(Dpm)-OH a practical intermediate for constructing disulfide-capable or thiol-functionalized molecular targets.

1. Peptide Synthesis

H-Cys(Dpm)-OH serves as a cysteine residue building block for solid-phase or solution-phase peptide assembly where controlled thiol protection is required to prevent premature disulfide formation or side reactions. The amino acid backbone, comprising a free carboxylic acid and an unprotected amine, can be converted into activated coupling forms or paired with standard peptide coupling reagents to form amide bonds at the cysteine position. The Dpm-protected thiol remains masked during chain elongation, supporting sequential introduction of additional residues without thiol-mediated crosslinking. Selective Dpm removal can later generate a reactive cysteine thiol for disulfide formation, native cysteine display, or further derivatization, aligning with peptide chemistry strategies for thiol-containing sequences and peptide analog construction.

2. Side-Chain Functionalization

H-Cys(Dpm)-OH supports chemical biology and synthetic organic chemistry programs focused on installing thiol-derived functionality at the cysteine side chain through controlled deprotection and subsequent derivatization. The Dpm group stabilizes the sulfur functionality during handling and coupling steps, while the underlying cysteine stereochemistry preserves defined spatial orientation for reactivity. Thiol generation after Dpm removal can enable formation of disulfides, thioether linkages, or thiol-reactive conjugation intermediates that participate in downstream scaffold elaboration. The resulting thiol-bearing derivatives can be used to generate functional peptide conjugates, reactive intermediates for linker installation, or sulfur-containing motifs used in structure-activity relationship studies.

3. Bioconjugation Chemistry

H-Cys(Dpm)-OH can be applied to bioconjugation workflows that require site-defined cysteine chemistry for constructing protein conjugates, peptide tags, or biomolecule-linked probes. The protected thiol functionality helps manage chemoselectivity by minimizing unintended reaction with nucleophiles or electrophiles during preparation of conjugation-ready molecules. The amino acid backbone supports incorporation into peptide carriers or linker segments that maintain defined attachment points to biological targets after thiol unmasking. Dpm deprotection can then provide a controlled handle for conjugation chemistries such as disulfide exchange or thiol-electrophile coupling, enabling downstream generation of labeled or functional biomolecule conjugates for biochemical research and analytical development.

4. Protected Amino Acid Chemistry

H-Cys(Dpm)-OH functions as a stereochemically defined, sulfur-protected amino acid intermediate for orthogonal protection planning in protected amino acid synthesis. The Dpm-protected thiol provides a chemically distinct protecting group compared with common thioether or acyl-based sulfur protections, supporting selective deprotection logic when multiple functional groups must survive peptide coupling and fragment assembly. The presence of amino and carboxylic acid groups allows integration into standard protected amino acid strategies, including conversion to activated derivatives for peptide coupling or incorporation into larger chiral intermediates. The compound's chiral cysteine framework enables consistent stereochemical outcomes in downstream peptide building block preparation and sulfur-functionalized intermediate generation for fine chemical synthesis.

5. Pharmaceutical Intermediate Preparation

H-Cys(Dpm)-OH is suitable for pharmaceutical intermediate preparation where cysteine residues and thiol-reactive motifs are used to build peptidomimetic structures, covalent-binding fragments, or linker-bearing intermediates. The Dpm-protected thiol can be carried through multi-step synthetic sequences that require suppression of thiol oxidation and side reactions, while the amino acid backbone supports conversion into coupling-ready forms for assembling amide-containing scaffolds. Controlled unmasking of the thiol enables access to reactive sulfur functionalities that can be further transformed into thioethers, disulfides, or other sulfur-containing linkers used in medicinal chemistry programs. The compound therefore supports process chemistry intermediate design for generating well-defined chiral building blocks consistent with industrial fine chemical synthesis routes.

6. Analytical Research Standards

H-Cys(Dpm)-OH can be employed in analytical research and method development requiring cysteine-containing standards that reflect protected thiol chemistry. The Dpm-protected side chain reduces uncontrolled thiol oxidation during sample preparation, supporting reproducible chromatographic and mass spectrometric behavior for protected amino acid derivatives. The defined stereochemistry at the cysteine center aids in distinguishing stereoisomeric or derivatization-dependent signals when developing quantitation methods for thiol-containing peptides and amino acid derivatives. Dpm deprotection capability also allows preparation of matched thiol-bearing reference materials, supporting analytical workflows that compare protected versus unmasked cysteine forms in peptide synthesis monitoring and biochemical sample characterization.

1. C-Peptide replacement therapy and sensory nerve function in type 1 diabetic neuropathy

2. Zeta-potential-changing nanoparticles conjugated with cell-penetrating peptides for enhanced transfection efficiency

3. Urinary Metabolites Associated with Blood Pressure on a Low-or High-Sodium Die

4. Cell-based adhesion assays for isolation of snake venom’s integrin antagonists

5. Low bone turnover and low BMD in Down syndrome: effect of intermittent PTH treatment