Product description
Upstream Building Block for the C18 Lipid Side Chain of Semaglutide (Core Function)
The prolonged glucose-lowering activity of Semaglutide depends on the reversible binding of its C18 stearic acid side chain at the Lys26 position to plasma albumin, thereby extending the peptide's circulating half-life. This product serves as the hydrophobic carbon-chain precursor at the terminal end of the complete lipid side chain. Its selectively protected mono-terminal structure prevents simultaneous coupling of both carboxyl groups, effectively avoiding undesired bis-conjugated by-products. This significantly improves the coupling selectivity with the γ-Glu-(AEEA)₂ fragment, minimizes side-chain synthesis impurities, and provides an essential starting material for the industrial-scale manufacture of Semaglutide lipid side chains.
Compatible with a Unified TFA Cleavage Strategy
The distal carboxyl group is protected as an OtBu ester, while the free COOH group remains available for site-specific amide coupling. During the final TFA deprotection step, the OtBu group can be removed simultaneously with all tert-butyl ester protecting groups on the Glu and AEEA segments, eliminating the need for stepwise deprotection and greatly simplifying downstream purification of the complete lipid side chain.
No Pharmacological or Cosmetic Activity
This material is a pure long-chain aliphatic ester intermediate without peptide structures or pharmacologically active functional groups. It cannot penetrate cell membranes or the skin barrier. Direct injection, oral administration, or topical application may result in residual tert-butyl ester decomposition products that can irritate mucosal tissues. Therefore, it is not a pharmaceutical preparation or a cosmetic ingredient.
Universal Hydrophobic Building Block for C18 Lipid-Modified Peptides
In addition to Semaglutide, this intermediate can be used in the synthesis of various C18 fatty acid-modified long-acting GLP-1 peptides and long hydrophobic linker arms for ADC payloads. Its mono-tert-butyl ester selective protection strategy effectively addresses the challenge of non-selective dual coupling associated with long-chain dicarboxylic acids, significantly reducing synthesis complexity, purification difficulty, and manufacturing costs for lipid-modified molecules.
This product is supplied exclusively as an upstream organic synthesis intermediate for pharmaceutical API manufacturing. It is intended solely for peptide side-chain synthesis during pharmaceutical production and is not suitable for direct injection, oral administration, or topical application.