Fmoc-S-trityl-D-Homocysteine

Fmoc-S-trityl-D-Homocysteine is a chiral, sulfur-containing homocysteine derivative bearing an Fmoc-protecting group on the amino function and a trityl (S-trityl) protecting group on the thiol, together with a free carboxylic acid. The D stereocenter at the α-carbon and the thioether-protected side chain enable controlled incorporation into peptide sequences while suppressing thiol oxidation and side reactions during coupling. The Fmoc carbamate supports standard base-labile deprotection workflows, whereas the bulky trityl group provides steric shielding of sulfur, influencing reactivity and compatibility with peptide coupling conditions. The resulting amino acid building block functions as a chemically stable intermediate for generating cysteine- or homocysteine-like thiofunctional motifs after orthogonal deprotection and downstream functional group transformation.

1. Protected Amino Acid Synthesis

Fmoc-S-trityl-D-Homocysteine serves as a protected amino acid intermediate for protected amino acid synthesis and chiral building block preparation in peptide chemistry. The Fmoc group on nitrogen and the S-trityl group on sulfur create orthogonal protection patterns that can be maintained through activation and coupling steps, while the free carboxylic acid enables conversion to activated esters or direct coupling partners. The D configuration provides stereochemical control for producing D-homocysteine-containing sequences and for preparing stereodefined analogs used in method development and structure-activity relationship studies. Orthogonal deprotection of Fmoc under basic conditions followed by thiol unmasking supports access to reactive thiol-containing derivatives for subsequent derivatization or conjugation.

2. Peptide Synthesis

Fmoc-S-trityl-D-Homocysteine is suitable for peptide synthesis workflows requiring incorporation of a protected thio-functional side chain at a defined position. The amino acid backbone contains a carboxylic acid for peptide bond formation and an Fmoc-protected amine that participates in standard solid-phase or solution-phase coupling strategies after deprotection cycles. The S-trityl thiol protection helps prevent disulfide scrambling and minimizes undesired thioether/thiol side reactions during iterative assembly and purification. After sequence construction, controlled removal of the trityl group can generate thiol-bearing peptide intermediates that can be further converted into thioether, disulfide, or thiol-reactive conjugation handles, supporting downstream peptide analog construction.

3. Bioconjugation Chemistry

Fmoc-S-trityl-D-Homocysteine supports bioconjugation chemistry by providing a protected thiol precursor that can be unmasked to generate site-reactive sulfur functionality. The thio-protecting trityl group stabilizes the sulfur center during handling and synthetic steps, while the Fmoc-protected amine allows the compound to be processed as a peptide-building block or as an amino acid derivative for linker installation. Thiol generation after orthogonal deprotection can enable formation of thioether linkages, disulfide-containing conjugates, or thiol-reactive adducts with electrophilic labeling reagents used in chemical biology research. Stereodefined D-homocysteine incorporation can be applied to create conjugates with defined spatial orientation of the sulfur functionality for probing molecular recognition and linker effects.

4. Peptidomimetics And SAR Studies

Fmoc-S-trityl-D-Homocysteine is applicable to peptidomimetics and structure-activity relationship studies where sulfur-containing side chains are used to tune conformation, polarity, and binding interactions. The protected thiol and carboxylic acid allow conversion into thio-functional analogs that can mimic cysteine-like or homocysteine-like pharmacophore elements while maintaining synthetic control over side-chain reactivity. Fmoc-enabled assembly supports integration into peptide-like scaffolds, whereas thiol unmasking enables conversion into stable thioether or disulfide motifs that may modulate stability and binding properties in SAR workflows. Stereochemical fidelity at the α-carbon supports the preparation of D-configured analog series for comparative studies in medicinal chemistry and molecular design.

5. Process Chemistry Intermediate

Fmoc-S-trityl-D-Homocysteine can be employed as a process chemistry intermediate for manufacturing routes that require protected sulfur amino acid derivatives with controllable deprotection steps. The combination of an Fmoc carbamate and an S-trityl thioether protection pattern supports stepwise processing where base-labile amine deprotection and thiol unmasking can be scheduled to match downstream transformations. The protected thiol minimizes oxidation during storage, purification, and scale-up handling, while the free carboxylic acid provides a defined handle for activation and coupling chemistry. The compound's structure aligns with fine chemical synthesis practices for producing stereodefined amino acid building blocks and thio-functional intermediates used in peptide manufacturing and specialized chemical production.

1. Proinsulin C-peptide and insulin: Limited pattern similarities of interest in inter-peptide interactions but no C-peptide effect on insulin and IGF-1 receptor signaling

2. Characterization of Novel P-Selectin Targeted Complement Inhibitors in Murine Models of Hindlimb Injury and Transplantation

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

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

5. P-selectin and Complement’s Role in a Neonatal Model of Germinal Matrix Hemorrhage-Induced Secondary Injury