I-Tetralinyl Group for Asparagine Side-Chain Protection, and Application to Bee-SolidPhase Peptide Synthesis of Mesotocin

Abstract

Mesotocin, a nonapeptide amide, was synthesised on a benzhydryl-resin using the Boc-strategy. Benzyl group was use~ in the protection of the side-chains of tyrosine and cysteine. Tetralinyl and benzhydryl groups were used to protect asparagtne and glutamine side-chains respectively. TFMSA-TFA-thioanisole-I,2-ethanedithiol (2:20:2: I v/v) was used on the peptide-resin un~er different cleavage conditions to obtain mesotocin in a one-pot reaction. The cleavage at 40 'Cfor two hours gave crude mesotocm, which onpurification by semi-preparative HPLC gave ayield of 49 %.