Solid-phase peptide synthesis of isotocin with amide of asparagine protected with 1-tetralinyl. Rifluoromethanesulphonic acid (tfmsa) deprotection, cleavage and air oxidation of mercapto groups to disulphide

Abstract

Isotocin, a nonapept ide amide, was synthesised on a benzhydryl-resin using the Bocst rat egy. Benzyl group was used in the pr otect ion of the side-ch ains of tyrosine, ser ine and cyst eine. Tetr alinyl group was used to protect aspar agine side-chain. TFMSA-TFA-thioanisole-1,2- ethanedithiol (2:20:2:1 v/v) was used on the pept ide-r esin under different cleavage conditions to obtain isotocin in a one-pot rea ct ion. The cleavage at 40 °C for two hours gave isotocin quantitatively. Isotocin could be isolated in 61% yield.