Peptide. XV. Synthese von Analoga des Bradykinins mit threo‐β‐Phenylserin

Abstract

Es wird die Synthese von Analoga des Bradykinins beschrieben, in denen das Phenylalanin in 5‐ oder 8‐Stellung bzw. in beiden Positionen durch L‐threo‐β‐Phenylserin ersetzt ist.

Amino Acid-Protecting Groups

“…Although the protected derivatives are the safest way to incorporate Ser, Thr, or Hyp into the peptide sequence, they can also be used with the free hydroxyl functionality. Protection is more necessary in SPS, because an excess of acylating agents is used, and for Ser, whose primary alcohol is more prone to acylation than the secondary alcohols of Thr and Hyp, which have been successfully used without protection in several syntheses, including solid phase. , Nevertheless, there are also some reports of the successful use of unprotected Ser in solution-phase synthesis, but care must be taken when choosing the activating agents. , …”

“…414,415 Nevertheless, there are also some reports of the succesful use of unprotected Ser in solution phase synthesis, but care must be taken when choosing the activating agents. 416,417 In peptide synthesis, hydroxyl funcionalities are protected as ethers, which are more stable than the corresponding carbamates and esters. The most used protecting groups for the Boc/Bn and Fmoc/ t Bu strategies are Bn (benzyl) and t Bu (tert-butyl) respectively.…”