| 摘要 |
<p>New cpds. are tyrosine-O-sulphate barium salt (I) and its N-acyl derivs. with acyl protecting groups in peptide chemistry. An N-acyltyrosine in a polar solvent or solvent mixt. is reacted with excess pyridine-SO3; the resulting soln. is extracted with water; the N-acyltyrosine-O-sulphate barium salt is pptd. from the aq. phase by the addn. of a soluble barium cpd.; and the acyl gp. is opt. eliminated in a conventional manner (e.g. an N-carbobenzoyl group can be eliminated by hydrogenolysis). (I) and its N-acyl derivs. are useful as intermediates for the total, synthesis of peptides or proteins contg. tyrosine-O-sulphate, e.g. the gastrins, cholecyetokinin-pancreozymin and caerulin. Surprisingly, the O-sulphate residue is retained during usual peptide-synthetic steps (including clearage of protecting groups). N-Carbobenzoxy tyrosine-O-sulphate barium slat is specifically claimed.</p> |
