Fmoc-Ile-Aib-Leu-Asp(OtBu)-OH

Fmoc-Ile-Aib-Leu-Asp(OtBu)-OH is a protected tetrapeptide building block commonly used in solid-phase peptide synthesis (SPPS). It contains the non-proteinogenic amino acid α-aminoisobutyric acid (Aib), which promotes α-helical structures in peptides. The N-terminal amino group is protected by the base-labile 9-fluorenylmethoxycarbonyl (Fmoc) group, while the aspartic acid side chain is protected with an acid-labile tert-butyl (OtBu) ester. This combination enables efficient, controlled peptide chain assembly. The compound is valuable for synthesizing complex peptides and peptidomimetics with specific structural and biological properties, facilitating research in drug discovery and materials science.

Appearance

• White to off-white solid powder

Source

• Produced synthetically via chemical synthesis

• Commercially available from peptide synthesis reagent suppliers

Molecular Weight and Structure

• Molecular Weight: Approximately 735.9 Da (may vary slightly with salt/hydration)

• Structure Highlights:

  • Fmoc group at N-terminus (9-fluorenylmethoxycarbonyl)

  • Isoleucine (Ile)

  • α-Aminoisobutyric acid (Aib)

  • Leucine (Leu)

  • Aspartic acid (Asp) with tert-butyl ester protecting side chain (OtBu)

Biological Activity

• No significant activity by itself

• Biological function is relevant when integrated into larger peptides

• Aib promotes α-helical conformations and may affect peptide-target interactions

• Aspartic acid contributes negative charge that can impact interactions with biomolecules

Purity and Microbial Contamination

Identity and Quality Control

Shelf Life and Storage

Application

• Solid-phase peptide synthesis (SPPS) building block

• Creation of peptides containing Tyr-Aib motifs for enhanced helicity

• Peptidomimetic synthesis

• Drug discovery targeting specific peptide conformations

• Design of self-assembling peptide-based materials

Key Characteristics

• Fmoc N-terminal protection enables selective base-labile cleavage

• OtBu protects aspartic acid side chain acid-labile, allowing controlled deprotection

• Aib residue promotes α-helical peptide structures

• Suitable for coupling with diverse amino acids to synthesize complex peptides

• Soluble in organic solvents like DMF, DMSO, and acetonitrile

Citation

• https://pubmed.ncbi.nlm.nih.gov/12765333/

• https://pubmed.ncbi.nlm.nih.gov/17269831/

• https://pubmed.ncbi.nlm.nih.gov/17865333/

• https://pubmed.ncbi.nlm.nih.gov/15471369/

• https://pubmed.ncbi.nlm.nih.gov/19583199/

• https://pubmed.ncbi.nlm.nih.gov/20387915/

• https://pubmed.ncbi.nlm.nih.gov/15200271/

• https://pubmed.ncbi.nlm.nih.gov/19697497/

• https://pubmed.ncbi.nlm.nih.gov/16548674/

• https://pubmed.ncbi.nlm.nih.gov/20536178/