Within Alfa Chemistry's non-canonical amino acid (ncAA) portfolio, unusual amino acids form a versatile category covering other non-standard residues not classified elsewhere. By incorporating these distinctive building blocks, researchers gain access to new side-chain functionalities, diverse stereochemistries, and backbone architectures that enhance receptor selectivity, metabolic stability, and biological activity in peptides and peptidomimetics.
Structural Diversity with Practical Benefits
Unusual amino acids feature non-standard side chains, cyclic constraints, halogenations, or backbone modifications. These properties help researchers:
- Increase protease resistance and membrane permeability
- Introduce reactive handles for labeling or conjugation
- Fine-tune pharmacokinetic and binding profiles
Representative Products
- Allyl- and Propargyl-Substituted Amino Acids
Ideal for click chemistry and post-synthetic labeling. Examples include:
- L-2-Allylglycine·HCl
- H-Allyl-D-glycine-OH
- H-Propargylglycine-OH·HCl
- Fmoc-D-Allylglycine-OH
- Boc-D-Propargylglycine-OH
- Cyclopropyl and Cyclopentyl Amino Acids
Rigid analogues that stabilize peptide secondary structures, such as:
- L-Cyclopropylalanine-OH
- Fmoc-L-Cyclopropylalanine-OH
- Aminocyclopentane derivatives (multiple stereoisomers)
- Halogenated and Fluorinated Phenylalanines
Residues adding unique electronic and steric properties to optimize receptor binding and stability, including:
- 3-Bromo-L-phenylalanine-OH
- Fmoc-3,5-Diiodo-D-tyrosine-OH
- Fmoc-3,4-Difluoro-L-phenylalanine-OH
- β- and γ-Modified Amino Acids
Residues imparting protease resistance and enabling novel secondary structures used in antimicrobial peptides, enzyme inhibitors and foldamers, such as:
- D-β-Homoserine-OH
- Boc-β-Cyano-D-alanine-OH
- Fmoc-L-β-Homoproline-OH
- Specialty Building Blocks
Including:
- L-Kynurenine-OH for immunomodulatory studies
- Statine·HCl for protease inhibitor research
- Cycloleucine-OH and DL-α-Methyltryptophan-OH for metabolic studies
- Fluorescent residues for imaging applications
Flexible Protection for Seamless Synthesis
Alfa Chemistry supplies unusual amino acids in Fmoc, Boc, Z, and mixed protection formats, compatible with standard solid-phase peptide synthesis. This flexibility enables direct integration of multifunctional residues without compromising yield or purity.
Empowering Innovation Across Industries
By offering one of the most comprehensive catalogs of unusual ncAAs, Alfa Chemistry supports pharmaceutical discovery, agrochemical development, and biomaterials engineering. These building blocks help create next-generation therapeutics, cell-penetrating peptides, conjugate vaccines, and targeted delivery systems.
