Patent ID: 6610655
Filing Date: 2003-08-26
Classification: A61K,C07K

Abstract:
A method for synthesizing a cyclopentapeptide compound, having a &bgr;-turn and &ggr;-turn with a main chain configuration of:Cyclo(-A1-A2-A3-A4-A5-) wherein each of A1, A3 to A5 is an a-amino acid selected from alanine, valine, norvaline, leucine, norleucine, isoleucine, alloisoleucine, phenylalanine, tyrosine, tryptophan, serine, threonine, aspartic acid, glutamic acid, ornithine, lysine, arginine, histidine, methionine and cysteine; and A2 is an &agr;-amino acid selected from alanine, valine, norvaline, leucine, norleucine, isoleucine, alloisoleucine, phenylalanine, tyrosine, tryptophan, serine, threonine, aspartic acid, glutamic acid, ornithine, lysine, arginine, histidine, methionine, cysteine and proline,said method comprising the steps of: (a) providing a D-&agr;-amino acid for each A1, A3 and A5 and providing a L-&agr;-amino acid for each A2 and A4; (b) synthesizing a linear pentapeptide constituting a precursor of said cyclopentapeptide, and (c) cyclizing said linear pentapeptide; thereby forming a &bgr;-turn at the portion of -A3-A4-A5-A1 and a &ggr;-turn at the portion of -A1-A2-A3- in said cyclopentapeptide and controlling the optical activity of the main chain of the cyclic pentapeptide, with the proviso that Cyclo (-A1-A2-A3-A4-A5-) is not Cyclo (-Asp-Pro-Val-Leu-Trp-), Cyclo (-Glu-Ala-Val-Leu-Trp-) and Cyclo (-Glu-Ala-alloIle-Leu-Trp-).