Formation of aminosuccinyl derivative from beta-phenacyl aspartyl peptides catalyzed by sodium thiophenoxide.
In the solid-phase synthesis of cholecystokinin 30-33, Trp-Met-Asp-Phe- amide, the beta-phenacyl ester was used to protect the beta-carboxyl of aspartyl residue. The ester was cleaved, on the solid support, with a 1 M solution of sodium thiophenoxide in DMF, prior to ammonolysis. The product, after purification by countercurrent distribution, was identified as a mixture of isoasparaginyl and aspartyl peptides. A study of the deprotection step, with sodium thiophenoxide, on a model peptide (t-butyloxycarbonyl-beta-phenacyl-aspartyl-phenylalanineamide) showed the rapid formation of the aminosuccinyl derivative, catalyzed by this reagent.
D000596:Amino Acids / Q000032:analysis; D003377:Countercurrent Distribution; D005755:Gastrins / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D008722:Methods; D009842:Oligopeptides / Q000138:chemical synthesis*; D012997:Solvents; D013386:Succinates; D013758:Tetragastrin / Q000138:chemical synthesis*
D000596:Amino Acids; D005755:Gastrins; D007202:Indicators and Reagents; D009842:Oligopeptides; D012997:Solvents; D013386:Succinates; D013758:Tetragastrin; C035623:tert-butoxycarbonyl-beta-phenacyl-aspartyl-phenylalanineamide