Fmoc-D-Met(O2)-OH is a protected, stereochemically specified amino acid derivative based on D-methionine bearing an oxidized sulfoxide side chain. The molecule contains an Fmoc-protected amino group and a free carboxylic acid, with the Met(O2) functionality reflecting a sulfoxide (S=O) oxidation state that modulates polarity and hydrogen-bonding behavior relative to unoxidized methionine. In peptide chemistry and chemical biology, it is employed as a building block for stepwise assembly of peptide sequences where the Fmoc group supports controlled amide-bond formation and the sulfoxide side chain provides a defined oxidation-state handle for structure-activity studies, protein-mimetic design, or analytical characterization of oxidation-sensitive motifs.
CAT No: CP25247
CAS No:1247791-23-6
Chemical Name:N-alpha-(9-Fluorenylmethyloxycarbonyl)-D-methionine sulfone
Fmoc-D-Met(O2)-OH is an Fmoc-protected D-methionine sulfoxide amino acid featuring a stereogenic center at the alpha carbon and a sulfoxide functionality on the methionine side chain. The molecule combines an N-(9H-fluoren-9-ylmethoxycarbonyl) protecting group with a free carboxylic acid, enabling controlled peptide coupling while maintaining orthogonal reactivity for downstream transformations. The sulfoxide group provides a polar, oxidized thioether motif that can participate in stereochemically sensitive chemistry and can serve as a handle for redox-aware derivatization or sulfoxide-to-sulfide interconversion strategies. The presence of both protected amine and unprotected acid makes it a practical chiral amino acid intermediate for peptide building block preparation and for designing methionine-oxidation mimics in synthetic and analytical workflows.
1. Peptide Synthesis
Fmoc-D-Met(O2)-OH is used in peptide synthesis workflows where Fmoc protection supports standard base-mediated N-deprotection and subsequent amide bond formation at the alpha-carboxyl group. The D-configuration at the amino acid stereocenter provides defined stereochemical control for incorporating D-methionine sulfoxide motifs into peptides and peptidomimetics. The sulfoxide side chain can be retained during coupling steps to generate oxidation-state-defined analogs, supporting structure-activity relationship studies that distinguish reduced thioether from oxidized sulfoxide behavior. Downstream peptide assembly can yield oxidation-state probes, protease- and stability-focused analog libraries, and sequence-defined materials where methionine oxidation is a design parameter in amino acid chemistry.
2. Peptidomimetics And SAR Studies
Fmoc-D-Met(O2)-OH is applied in medicinal chemistry research for constructing peptidomimetics and SAR-focused analogs that incorporate a stereochemically defined methionine sulfoxide residue. The Fmoc-protected amine and free carboxylic acid enable incorporation into peptide scaffolds using peptide coupling chemistry, while the sulfoxide introduces a distinct polarity and hydrogen-bond acceptor profile relative to methionine. The D-stereochemistry supports investigations into stereochemical effects on conformational preferences, binding-site recognition, and metabolic stability proxies that are sensitive to side-chain oxidation state. Resulting sulfoxide-bearing analogs can be used as biochemical research intermediates for generating structure-defined compound sets and for guiding fragment-to-lead optimization through oxidation-state-aware molecular design.
3. Chemical Biology Probes
Fmoc-D-Met(O2)-OH is suitable for chemical biology applications that require methionine-oxidation mimics for studying protein modification patterns and redox-dependent recognition. The sulfoxide functionality can serve as a chemically discriminating side-chain element in synthetic peptide probes, enabling design of substrates or binding ligands that reflect oxidized methionine environments. Fmoc protection allows controlled assembly of probe peptides with defined N-terminus architecture, while the carboxylic acid permits further derivatization or conjugation strategies after peptide construction. The resulting oxidation-state-defined probes can be employed in biochemical research intermediate preparation for assays that interrogate recognition, stability, and side-chain-dependent molecular interactions.
4. Bioconjugation Chemistry
Fmoc-D-Met(O2)-OH is utilized in bioconjugation and biomolecule modification pipelines where peptide-derived linkers bearing a sulfoxide side chain can be incorporated into conjugates. The Fmoc group supports stepwise peptide assembly, and the free carboxyl group provides a functional handle for conversion into activated ester or amide-forming intermediates during linker construction. The sulfoxide can influence conjugate polarity and local solvation, which may affect conjugate solubility and interaction with biomolecular targets in labeling or immobilization workflows. Downstream products include sulfoxide-containing peptide conjugates, affinity reagents, and analytical standards that rely on stereodefined amino acid incorporation for consistent molecular recognition.
5. Protected Amino Acid Intermediate
Fmoc-D-Met(O2)-OH is employed as a protected amino acid intermediate in process chemistry and fine chemical synthesis for manufacturing peptide building blocks with controlled stereochemistry and oxidation-state fidelity. The combination of Fmoc N-protection and a free carboxylic acid supports scalable peptide coupling compatibility, while the sulfoxide group provides a stable functional motif that can be carried through multiple synthetic steps before final deprotection or functional conversion. The D-stereocenter enables production of enantiomerically defined materials for stereochemical studies, including D-amino acid-containing peptides and oxidation-state analogs. The compound's structural features make it suitable for route design where orthogonal protection and predictable peptide coupling behavior are required for industrial intermediate preparation and consistent downstream assembly.
6. Analytical Research Standards
Fmoc-D-Met(O2)-OH is applied in analytical research to generate reference materials and derivatization targets for method development involving amino acid oxidation-state discrimination. The sulfoxide side chain provides a distinct chemical signature compared with methionine, supporting analytical workflows that require defined oxidized amino acid standards or peptide fragments. Fmoc protection enables preparation of standardized peptide segments that can be used as calibration components, retention-time anchors, or structural controls in LC-MS and related characterization methods. The stereodefined D-methionine sulfoxide motif supports reproducible analytical comparisons across synthetic batches and supports amino acid derivatization studies that track oxidation-state transformations in synthetic and biochemical contexts.
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