Roy U, Gazis D, Schwartz I L, Roy J
Int J Pept Protein Res. 1983 Oct;22(4):398-403. doi: 10.1111/j.1399-3011.1983.tb02108.x.
The depsipeptide [8-alpha-hydroxyisocaproic acid, 9-glycolic amide]-oxytocin, which has ester linkages replacing the peptide linkages between the 7th and 8th and the 8th and 9th residues of oxytocin, has been synthesized by a (6 + 3) condensation of Boc-tocinoic acid with Pro-O-HyIc-O-Glyc-NH2, followed by deprotection of the resulting product. The analog exhibited the following activities in rats: 258 +/- 11 and 28 +/- 5 U/mg, uterus in vitro in the absence and presence, respectively, of Mg+2; 54 +/- 4 U/mg, uterus in vivo; 19.3 +/- 2.1 U/mg, milk ejection; 0.153 +/- 0.026 U/mg, antidiuretic activity; and no pressor activity. The need for the presence of the peptide linkages mentioned above as sources for internal hydrogen bonds to stabilize the "biologically significant" conformation is discussed.
缩肽[8-α-羟基异己酸，9-乙醇酰胺]-催产素已通过Boc-托西诺酸与Pro-O-HyIc-O-Glyc-NH2的(6 + 3)缩合反应合成，该缩肽具有酯键取代了催产素第7和第8位以及第8和第9位残基之间的肽键，随后对所得产物进行脱保护。该类似物在大鼠中表现出以下活性：分别在不存在和存在Mg+2的情况下，离体子宫活性为258±11和28±5 U/mg；体内子宫活性为54±4 U/mg；排乳活性为19.3±2.1 U/mg；抗利尿活性为0.153±0.026 U/mg；且无升压活性。文中讨论了上述肽键作为内部氢键来源以稳定“生物学上重要”构象的必要性。
