Somatostatin analogues
The invention provides cyclo[{4-(NH 2 —C 2 H 4 —NH—CO—O—)Pro}-Phg-DTrp-Lys-Tyr(4-Benzyl)-Phe], optionally in protected form, or a pharmaceutically acceptable salt or complex thereof, which has interesting pharmaceutical properties.
1. A process for the production of a compound of formula
or a salt thereof, comprising cyclising a linear peptide selected from the group consisting of
DTrp-Lys-Xa1-Phe-Xa2-Xa3,
Xa3-DTrp-Lys-Xa1-Phe-Xa2,
Xa2-Xa3-DTrp-Lys-Xa1-Phe,
Phe-Xa2-Xa3-DTrp-Lys-Xa1,
Xa1-Phe-Xa2-Xa3-DTrp-Lys, and
Lys-Xa1-Phe-Xa2-Xa3-Trp,
wherein Xa1 represents O-benzyl-tyrosine, Xa2 represents 2-carboxy-4-(2-aminoethyl-carbonyloxyamino)pyrrolidine, and Xa3 represents phenylglycine, respectively, in protected form or in protected and polymer bound form and removing the protecting group(s) or cleaving from the polymer and removing the protecting group(s), in such a way to obtain said compound, and recovering said compound in free or salt form.
2. The process according to claim 1 , wherein said cyclizing of said linear peptide produces a bond between the carboxyl group of O-benzyl-tyrosine and the amino group of Phe.