A heptacosapeptide having the following structural formula: Boc-His(Boc)-Ser(Bu.sup.t)-Asp(OBu.sup.t)-Gly-Thr(Bu.sup.t)-Phe-Thr(Bu.sup. t)-Ser(Bu.sup.t)-Glu(OBu.sup.t)-Leu-Ser(Bu.sup.t)-Arg(X)-Leu-Arg(X)-Asp(OBu .sup.t)-Ser(Bu.sup.t)-Ala-Arg(X)-Leu-Gln-Arg(X)-Leu-Leu-Gln-Gly-Leu-Val-NH. sub.2, in which X is a group having the formula: ##STR1## where R is an alkyl or alkoxy and m is an integer of 1 to 3, provided that R's may be the same or different in case m is 2 or 3. The heptacosapeptide may be converted to a secretin.
一种具有以下结构式的七十肽:Boc-His(Boc)-Ser(Bu.sup.t)-Asp(OBu.sup.t)-Gly-Thr(Bu.sup.t)-Phe-Thr(Bu.sup.t)-Ser(Bu.sup.t)-Glu(OBu.sup.t)-Leu-Ser(Bu.sup.t)-Arg(X)-Leu-Arg(X)-Asp(OBu.sup.t)-Ser(Bu.sup.t)-Ala-Arg(X)-Leu-Gln-Arg(X)-Leu-Leu-Gln-Gly-Leu-Val-NH.sub.2,其中X是具有以下公式的基团:##
STR1##其中R是烷基或烷
氧基,m是1至3的整数,但如果m为2或3,则R可以相同或不同。该七十肽可转化为胆汁素。