In the past few years ß-peptides and other ß-amino acid containing oligomers have emerged as very promising tools in medicinal chemistry, as they exhibit remarkable biological activity together with an extraordinary biological stability.¹ ß-Peptides have shown to be stable to common peptidases for at least two days.² Recently, a cyclic ß-tetrapeptide was synthesized with biological activity similar to somatostatine, an important endogenous neurotransmitter and inhibitor of hormone secretion.³ Systematic replacement of an ß-amino acid by an ß-amino acid residue resulted in a hybrid oligopeptide which binds to major histocompatibility complex (MHC) proteins, while showing enhanced stability towards proteolysis.^4,5 Another important aspect of ß-peptide oligomers is their ability to fold into well defined and stable helical-, turn- and pleated sheet-conformations in solution.^6-9 The picture aside shows a ß-peptide forming a two-stranded ß-pleated sheet connected by a hairpin turn. This sheet-and-turn structure was created and analysed by NMR in solution by Seebach and coworkers. It complements the similar structure described by Gelmann et al.¹⁰ by revealing the opposite orientation of the net dipole. Further remarkable applications of ß-amino acids are the use as protease inhibitors,¹¹ precursors for antibiotics¹² and building blocks in cryptophycins.^13,14

New offerings in this rapidly expanding field are added monthly! When you cannot find the amino acid you are looking for, or for additional technical information, please contact your local Sigma-Aldrich Office.

* Produced by Ciba Specialty Chemicals Inc.

REFERENCES:

1. Borman, S. Chem. Eng. News 1999, 77, 27.
2. Seebach, D. Matthews, J. L. Chem Comm. 1997, 2015.
3. Seebach D. et al., Angew. Chem. Int Ed. 1999, 38, 1223.
4. Rognan, D. et. al., J. Med. Chem. 1999, 42, 2318.
5. Rognan, D. et. al., J. Biol. Chem. 2001, 27, 24525.
6. Seebach, D. et al., Angew. Chem. Int Ed. 1999, 38, 1595.
7. Gademann, K. et al., Helv. Chim. Acta 1999, 82, 1.
8. Gellman, S. H. et al., J. Am. Chem. Soc. 1999, 121, 6206.
9. Gellman, S. H. et al., J. Am. Chem. Soc. 1999, 121, 7574.
10. Gellman, S. H. et al., J. Am. Chem. Soc. 1998, 120, 10555.
11. Takashiro et al., Bioorg. & Med. Chem. 1999, 7, 2063.
12. Tymiak, A. A. et al., J. Org. Chem. 1989, 54, 1149.
13. Eggen, M. et al., Org. Lett. 2001, 12, 1813.
14. White, J. D. J. Org. Chem. 1999, 64, 6206.