The pentapeptide, thymopentin (Arg 1-Lys 2-Asp 3-Val 4-Tyr 5) is known for its activity as an immunomodulating drug, but with limited half-life in plasma. In this first paper of a series of three studies, the synthesis of analogs stabilized at the peptide bond between the C-terminal amino acids via insertion of a ketomethylene moiety is described. N-Blocked pseudopeptides containing Val (k) Phe, Ala (k) Phe, and Val (k) Val units were prepared ...
