Ac-Met(O)-OH is an acetylated methionine-derived amino acid derivative featuring a methionine backbone bearing an oxidized thioether side chain consistent with a sulfoxide (Met(O)) and an N-acetyl (Ac) modification on the amino terminus. The molecule contains a free carboxylic acid (-COOH) and a sulfoxide-functionalized side chain that can participate in polarity and coordination changes relative to unoxidized methionine, while the N-acetyl group reduces the amino group's basicity and chemoselectivity toward acylation. Ac-Met(O)-OH is used as a defined building block or reference intermediate in peptide chemistry and analytical method development for studying methionine oxidation patterns, preparing modified peptide analogues, and supporting structure-property investigations of sulfoxide-containing amino acid residues.
CAT No: CP26178
CAS No:108646-71-5
Synonyms/Alias:AC-MET(O)-OH;Acetyl-L-methioninesulfoxide;108646-71-5;N-Acetylmethionineoxide;AC1OLR8H;N-AcetylmethionineS-oxide;SCHEMBL1129578;CHEMBL1221835;CTK8E9073;6101AH;AKOS015909360;RT-011184;(2S)-2-acetamido-4-methylsulfinylbutanoicacid;K-0613;I14-34126
Ac-Met(O)-OH is an acetylated methionine derivative featuring a protected α-amino group (Ac) and a methionine side chain bearing an oxidized sulfur functionality (Met(O)), supplied as an acid-form building block for peptide and protein chemistry workflows. This structure is commonly leveraged when the oxidation state of the methionine residue (sulfoxide form) needs to be represented or mimicked during peptide synthesis, analytical reference preparation, or chemical protein studies. The combination of an acetylated amino terminus and the sulfoxide side chain makes it a practical reagent for constructing defined Met(O)-containing sequences and for controlling side-chain oxidation state in downstream characterization.
1. Sulfoxide-Defined Peptide Synthesis
Ac-Met(O)-OH is used by peptide synthesis groups to incorporate a methionine sulfoxide residue in defined peptide sequences where oxidation state control is required. Researchers preparing oxidation-sensitive peptides, protease substrate panels, or sequence standards often select this acetylated derivative to ensure the N-terminus is capped consistently, reducing variability introduced by free amino reactivity during coupling and purification. In custom peptide manufacturing and academic peptide chemistry, Met(O)-containing segments are frequently required for method development in LC-MS/MS peptide mapping, oxidation-state comparisons, and peptide stability studies under defined chemical conditions.
2. Oxidation State Analytical Standards
Ac-Met(O)-OH serves as a reference material for analytical chemistry workflows that require a chemically defined methionine sulfoxide species. LC-MS and targeted MS/MS method development teams use this compound to verify chromatographic behavior, retention time alignment, and fragmentation patterns for Met(O)-containing analytes, including in peptide oxidation studies and sample normalization experiments. Stable oxidation-state representation is particularly valuable when comparing reduced methionine versus sulfoxide forms, since the side-chain oxidation state directly affects mass and ionization behavior, and a defined building block helps avoid ambiguity from mixed oxidation products.
3. Met(O) Residue Modeling Studies
Ac-Met(O)-OH is applied in chemical biology and protein chemistry research to model or represent Met(O) residues in simplified peptide contexts used for mechanistic and interaction studies. Protein engineering and bioconjugation teams often rely on short, defined Met(O)-containing peptides to evaluate how sulfoxide-bearing side chains influence local chemistry, labeling compatibility, or chemical reactivity during workflow development. Because the compound carries an acetylated amino terminus, it can be used to standardize terminal chemistry when the experimental focus is on the oxidized methionine side chain rather than on N-terminal effects.
4. Pharmaceutical Intermediate and Sequence Building
Ac-Met(O)-OH is also used in downstream synthetic development as a defined amino acid derivative for assembling Met(O)-containing intermediates and sequence fragments in larger synthetic programs. Pharmaceutical intermediate development groups and specialty peptide reagent manufacturers may incorporate this building block when preparing protected or semi-protected fragments that later feed into longer peptide assemblies or analytical reference sets. The presence of the oxidized sulfur functionality supports workflows where the oxidation state must be carried through synthesis and preserved for characterization, ensuring that the final intermediate or fragment corresponds to the intended Met(O) form rather than an undefined mixture.
2. Adipose tissue is a key organ for the beneficial effects of GLP-2 metabolic function
3. Myotropic activity of allatostatins in tenebrionid beetles
4. The spatiotemporal control of signalling and trafficking of the GLP-1R
If you have any peptide synthesis requirement in mind, please do not hesitate to contact us at . We will endeavor to provide highly satisfying products and services.
Creative Peptides is a trusted CDMO partner specializing in high-quality peptide synthesis, conjugation, and manufacturing under strict cGMP compliance. With advanced technology platforms and a team of experienced scientists, we deliver tailored peptide solutions to support drug discovery, clinical development, and cosmetic innovation worldwide.
From custom peptide synthesis to complex peptide-drug conjugates, we provide flexible, end-to-end services designed to accelerate timelines and ensure regulatory excellence. Our commitment to quality, reliability, and innovation has made us a preferred partner across the pharmaceutical, biotechnology, and personal care industries.
Read More