$542.86 - $1628.57
S-Methyl-L-Cysteine (CAS 1187-84-4) is supplied as a Sulfur-containing amino-acid derivative. In research synthesis, it is most relevant to amino-acid metabolism, sulfur chemistry and analytical research and sulfur amino-acid research, reference chemistry and metabolic studies.
Treat as a defined amino-acid derivative rather than an SPPS-ready protected monomer unless a specific route is designed around the free functional groups. Before substitution into an established synthesis, compare stereochemistry, protecting-group orthogonality and downstream deprotection requirements.
Product Information
| Product Name | S-Methyl-L-Cysteine |
| Catalog No. | AS4204 |
| CAS No. | 1187-84-4 |
| Molecular Formula | C4H9NO2S |
| Molecular Weight | 135.18 g/mol |
| Compound Type | Sulfur-containing amino-acid derivative |
| Primary Research Use | Amino-acid metabolism, sulfur chemistry and analytical research |
Research Identity and Use
S-Methyl-L-Cysteine is best treated as the defined amino-acid derivative itself rather than as a generic peptide-synthesis reagent. Its value is in reference, metabolic, analytical or small-molecule studies that require the exact modified amino-acid entity.
Analytical and Procurement Considerations
Exact stereochemistry, CAS identity, water content and assay can matter when the material is used for quantitative comparison or as a synthetic starting point. Lot-specific COA data should be matched to the intended measurement.
Route Planning
Because the compound is not configured as a standard Fmoc-protected SPPS monomer, additional protection or activation may be needed if it is incorporated into a larger synthetic target.
Additional chemistry is available in the current small-molecule range.
Product Documents
MSDS - S-Methyl-L-Cysteine (AS4204)
The Safety Data Sheet provides product identification, hazard information, handling and storage guidance, exposure controls, transport information, and regulatory information for laboratory use.
Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.
Frequently Asked Questions
Is this product an SPPS-ready Fmoc building block?
No. It is supplied as the defined amino-acid derivative shown in the product identity.
What is the main procurement check?
Confirm stereochemistry, CAS, formula, assay and lot-specific analytical documentation.
Can it be used as a synthetic starting material?
Yes, but additional protection or activation may be required depending on the intended route.