SOLID-PHASE PEPTIDE SYNTHESIS OF ISOTOCIN WITH AMIDE OF ASPARAGINE PROTECTED WITH 1-TETRALINYL. TRIFLUOROMETHANESULPHONIC ACID (TFMSA) DEPROTECTION, CLEAVAGE AND AIR OXIDATION OF MERCAPTO GROUPS TO DISULPHIDE

Isotocin, a nonapeptide amide, was synthesised on a benzhydryl-resin using the Boc-strategy. Benzyl group was used in the protection of the side-chains of tyrosine, serine and cysteine. Tetralinyl group was used to protect asparagine side-chain. TFMSA-TFA-thioanisole-1,2-ethanedithiol (2:20:2:1 v/v) was used on the peptide-resin under different cleavage conditions to obtain isotocin in a one-pot reaction. The cleavage at 40 ° C for two hours gave isotocin quantitatively. Isotocin could be isolated in 61% yield. (Received February 13, 2001; revised August 31, 2001) Bull.Chem.Soc.Ethiop. 2001, 15(2), 143-15

Solid-Phase Peptide Synthesis of Arginine-vasopressin with Amide Side-chain of Asparagine Protected with 1-Tetralinyl Group

Arginine-vasopressin, a nonapeptide amide, was synthesized on a benzhydryl-resin using the Boc-strategy. Benzyl group was used in the protection of sulfhydryl group of cysteine and tyrosine side-chain. Benzhydryl, tetralinyl and tosyl groups were used in the protection of glutamine, asparagine and arginine side-chains respectively. TFMSA-TFA-thioanisole-1,2-ethanedithiol (2:20:2:1 v/v) was used to cleave the peptide from  the resin under different conditions to obtain arginine-vasopressin in a one-pot reaction. The cleavage at 40°C for two hours gave arginine-vasopressin quantitatively (77% yield) Keywords: Solid-Phase Peptide Synthesis, resin, protecting group, cleavage, nonapeptide

1-Tetralinyl as Carboxamide-Protecting Group for Asparagine and Application to N-alpa- t-Butyloxycarbonyl (Boc) Solid-phase Peptide Synthesis of Oxytocin

Oxytocin, a nonapeptide amide, was synthesized on a benzhydryl-resin using the Boc strategy. Benzyl group was used in the protection of sulfhydryl group of cysteine and tyrosine side-chain. Benzhydryl and tetralinyl groups were used in the protection of glutamine and asparagine side-chains respectively. TFMSA-TFA-thioanisole-1,2-ethanedithiol (2:20:2:1 v/v) was used on the peptide-resin under different cleavage conditions to obtain oxytocin in a one-pot reaction. The cleavage at 40°C for two hours gave oxytocin quantitatively. Oxytocin could be isolated in 56% yield. Keywords: Boc-strategy, Solid-phase peptide Synthesis, nonapeptide, resin, protecting grou