Unnatural amino acids with several positive charges are useful tools for expanding the chemical space in peptide design. They can be employed as mimics of natural amino acids in peptides, or as building blocks for combinatorial chemistry. The polarity of cationic amino acids can improve cellular uptake of peptides, since a high number of positive charges in peptides seem to correlate with high uptake efficiency in human cells. Consequently, membrane-interacting peptides and antimicrobial peptides usually bear several basic residues. Furthermore, many biologically active natural products contain non-canonical cationic amino acids.

Triamino acids are also interesting for the preparation of dendrimers with a higher degree of amine functionalization than lysine dendrimers.

We now offer Fmoc-L-Dap(2-Boc-aminoethyl)-OH as our first triamino acid building block, and are currently working on expanding our portfolio with further analogous triamino acids.

→ Do you require a different triamino acid, or any other non-canonical amino acid building blocks? Send us your enquiry, and we will be pleased to provide you with an offer as quickly as possible.

References:

• Synthesis and evaluation of antineurotoxicity properties of an amyloid-[small beta] peptide targeting ligand containing a triamino acid; D. Honcharenko, P. P. Bose, J. Maity, F. R. Kurudenkandy, A. Juneja, E. Floistrup, H. Biverstal, J. Johansson, L. Nilsson, A. Fisahn and R. Stromberg; Organic & Biomolecular Chemistry 2014; 12: 6684-6693. doi:10.1039/c4ob00959b
• Solid-phase route to Fmoc-protected cationic amino acid building blocks; J. D. Clausen, L. Linderoth, H. M. Nielsen and H. Franzyk; Amino Acids 2012; 43: 1633-1641. doi:10.1007/s00726-012-1239-5
• The Medicinal Chemistry of Peptides; J. J. J. Nestor; Current medicinal chemistry 2009; 16: 4399-4418. doi:http://dx.doi.org/10.2174/092986709789712907
• Synthesis of chemically modified bioactive peptides: recent advances, challenges and developments for medicinal chemistry; S. R. Gracia, K. Gaus and N. Sewald; Future medicinal chemistry 2009; 1: 1289-1310. doi:10.4155/fmc.09.97
• Cell-penetrating peptides as delivery vehicles for biology and medicine; K. M. Stewart, K. L. Horton and S. O. Kelley; Organic & Biomolecular Chemistry 2008; 6: 2242-2255. doi:10.1039/b719950c
• Homochiral 4-Azalysine Building Blocks:  Syntheses and Applications in Solid-Phase Chemistry1; S. R. Chhabra, A. Mahajan and W. C. Chan; The Journal of Organic Chemistry 2002; 67: 4017-4029. doi:10.1021/jo010456e