438579-77-2

Upstream product

• 13139-14-5 Boc-Trp-OH 
• 438579-63-6 [(2S,6S)-6-((S)-1-tert-Butoxycarbonylamino-pentyl)-4-((S)-1-carbamoyl-2-phenyl-ethyl)-3-oxo-piperazin-2-yl]-acetic acid methyl ester 
• 431059-55-1 (S)-2-{(S)-2-tert-Butoxycarbonylamino-1-[((S)-1-carbamoyl-2-phenyl-ethylamino)-methyl]-hexylamino}-succinic acid dimethyl ester 

Relevant academic research and scientific papers

2-Oxopiperazine-based gamma-turn conformationally constrained peptides: synthesis of CCK-4 analogues.

2-Oxopiperazine derivatives 1 have been designed as mimetics of gamma-turn conformationally constrained tripeptides. The synthetic pathway devised for the preparation of both epimers of 1 at C(5) involves a reductive amination of cyanomethyleneamino pseudopeptides with amino acid derivatives, followed by regiospecific lactamization of the resulting C-backbone branched pseudopeptides. The versatility of this methodology is illustrated in the synthesis of analogues of the tetrapeptides Boc-[Nle(31)]-CCK-4 and Boc-[Lys(o-tolylaminocarbonyl)(31)]-CCK-4. The introduction of the new conformational restriction into these Boc-CCK-4 analogues led to a loss of 2 or 3 orders of magnitude in the affinity at CCK receptors. These results suggest the absence of a gamma-turn in the bioactive conformation of the C-terminal tripeptide of CCK-4.