Product description
Preassembled Complete C18 Side Chain Carboxylic Acid for Long-Acting Semaglutide
The prolonged glucose-lowering activity of Semaglutide relies on the C18 stearic acid + γ-Glu + bis-AEEA structure attached to the lysine residue. The C18 fatty acid reversibly binds to plasma albumin, significantly extending the in vivo half-life, while the bis-AEEA polyether spacer optimizes the balance between lipophilicity and aqueous solubility, thereby improving peptide formulation performance.
Conventional synthesis requires four sequential coupling steps involving the fatty acid, γ-Glu, and two AEEA units. This multistep process involves repeated activation reactions, resulting in increased impurity formation and substantial material loss. This product provides the fully assembled lipid side chain with a free terminal carboxyl group, requiring only a single activation step for direct solid-phase conjugation to the lysine residue of the peptide backbone. By eliminating multiple side-chain assembly steps, it significantly shortens the synthesis workflow, improves overall Semaglutide API yield, and is ideally suited for large-scale industrial solid-phase manufacturing.
Orthogonal Acid-Labile Protection with One-Step Global Deprotection
The carboxyl groups on both the fatty acid moiety and the glutamic acid side chain are protected with OtBu tert-butyl esters, ensuring excellent stability throughout solid-phase synthesis while minimizing undesired side reactions. All tert-butyl protecting groups are simultaneously removed during the final TFA cleavage, yielding the fully deprotected, lipid-modified Semaglutide peptide in a single step. This strategy is fully compatible with standard Fmoc solid-phase peptide synthesis (SPPS) workflows.
No Pharmacological or Cosmetic Activity
This molecule contains a long hydrophobic C18 alkyl chain together with multiple OtBu tert-butyl ester protecting groups. Due to its large molecular size, it cannot penetrate cell membranes or the skin barrier and exhibits no intrinsic biological activities such as glucose regulation, collagen stimulation, skin whitening, or soothing effects. Direct injection, oral administration, or topical application may leave residual tert-butyl ester degradation products, potentially causing skin or mucosal irritation. Therefore, it is not intended for pharmaceutical formulations or cosmetic applications.
Universal Solid-Phase Side Chain Intermediate for C18 Lipid-Modified Long-Acting GLP Peptides
In addition to Semaglutide, this intermediate is suitable for the solid-phase synthesis of other C18 fatty acid-modified long-acting GLP-1 peptides. The preassembled complete side-chain carboxylic acid overcomes the challenges of inefficient stepwise coupling and costly purification associated with highly hydrophobic lipid chains, making it a core intermediate for industrial-scale synthesis of long-acting GLP peptide therapeutics.
This product is supplied exclusively as an industrial intermediate for pharmaceutical API synthesis. It is intended solely for factory-scale solid-phase peptide synthesis and is not suitable for direct injection, oral administration, or topical application.