Fmoc-Leu-Aib-OH

Fmoc-Leu-Aib-OH is a dipeptide building block frequently utilized in solid-phase peptide synthesis (SPPS) for constructing peptides with tailored structural properties. It combines leucine (Leu), a hydrophobic amino acid commonly found in proteins, with α-aminoisobutyric acid (Aib), a non-proteinogenic amino acid known for inducing helical conformations, particularly α-helices and 310-helices. The Fmoc (9-fluorenylmethoxycarbonyl) group provides N-terminal protection, allowing controlled deprotection and coupling in SPPS. Aib introduces conformational constraint promoting well-defined secondary structures. Leucine adds hydrophobicity, influencing peptide-protein interactions or membrane affinity. Fmoc-Leu-Aib-OH is valuable for synthesizing peptides with enhanced stability, specific binding affinities, and desired structural characteristics relevant in drug design, biomaterials, and peptide folding studies.

Appearance

• White to off-white solid powder.

Source

• Synthetically produced through chemical synthesis. Commercially available from peptide synthesis reagent suppliers.

Molecular Weight and Structure

• Molecular Weight: Approximately 438.5 g/mol (based on formula C24H28N2O5)

• Structure consists of:

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

  • Leucine (Leu) residue

  • α-Aminoisobutyric acid (Aib) residue

  • Free carboxyl group at C-terminus

• For chemical structure, please refer to chemical databases such as PubChem or ChemSpider.

Biological Activity

• Generally biologically inactive as isolated dipeptide.

• Biological activity depends on the larger peptide sequence it’s incorporated into.

• Aib strongly influences peptide conformation; Leu contributes hydrophobic interactions relevant for peptide-protein binding or membrane affinity.

Purity and Microbial Contamination

• Purity: Typically ≥ 95% by HPLC analysis.

• Microbial contamination should be minimal or absent for biological applications.

• Suppliers typically provide COAs with results from bacterial endotoxin tests (LAL assay) and sterility testing.

Identity and Quality Control

• Identity confirmed by:

  • Mass Spectrometry (MS) for molecular weight verification

  • Nuclear Magnetic Resonance (¹H and ¹³C NMR) spectroscopy for structural verification

  • Infrared (IR) spectroscopy for functional group confirmation

• Quality confirmed by:

  • HPLC for purity

  • Optical rotation for enantiomeric purity (Leu residue)

  • Amino acid analysis after hydrolysis confirming correct composition

Shelf Life and Storage

Application

• Solid-Phase Peptide Synthesis (SPPS) building block

• Synthesis of α-helical and 310-helical peptides

• Peptidomimetic synthesis mimicking peptide structure and function

• Drug discovery targeting protein-protein interactions or membrane-related conformations

• Biomaterial design with specific structural properties

• Studies on peptide folding and structure-function relationships

Key Characteristics

• Fmoc protection enables base-labile N-terminal deprotection during SPPS

• Aib promotes helical conformations and stability

• Leucine provides hydrophobic character

• Versatile for coupling to other amino acids to create diverse peptide sequences

• Soluble in organic solvents such as DMF, DMSO, and acetonitrile

Citation 

• Search for “Fmoc-Leu-Aib-OH peptide synthesis” for relevant papers

• Research on “Aib peptide helix” or “α-aminoisobutyric acid peptide conformation”

• Articles on “helical peptide design” or “310-helical peptide synthesis” mentioning leucine

• Studies on “leucine-rich repeat peptides” for structural contexts

• Supplier technical datasheets and application notes

• Databases: Reaxys, SciFinder, PubMed for chemical and biological literature

• Search “solid phase peptide synthesis” + “Aib” + “Leu” to find related work

• Papers on Aib-containing peptides with enhanced stability and membrane interaction

• Google Scholar searches with keywords like “Fmoc-Leu-Aib-OH synthesis,” “Aib Leu peptide helix,” or “Aib conformation”