Fmoc-β-Ala-Phe-OH SPPS Amino Acid Impurity Research Coupling Efficiency

This is the primary application.

• Used as a dipeptide building block in peptide chain elongation
• Compatible with the Fmoc strategy (base-labile protecting group)
• The β-alanine unit:
  • Introduces extra flexibility
  • Reduces steric hindrance
  • Improves coupling efficiency in certain sequences

This structure is useful in medicinal chemistry:

• β-Ala acts as a flexible linker
• Phe (phenylalanine) provides hydrophobic and aromatic interactions

Typical purposes:

• Optimization of receptor binding (especially GPCR-related peptides)
• Improving biological activity and selectivity
• Modulating metabolic stability

Widely used as a spacer unit in complex systems:

• PEGylation
• Peptide–small molecule conjugates
• Drug delivery systems

β-Ala offers a longer and more flexible spacer than Glycine