(1-Beta-mercaptopropionic acid, 2-(3,5-dibromo-L-tyrosine))oxytocin, a potent inhibitor of oxytocin.
[1-Beta-Mercaptopropionic acid,2-(3,5-dibromo-L-tyrosine)]oxytocin was synthesized from a protected polypeptide intermediate that had been prepared by the condensation of S-ethylcarbamoyl-beta-mercaptopropionyl-3,5-dibromotyrosine with H-Ile-Gln-Asn-Cys(Ec)-Pro-Leu-Gly-NH2, using dicyclohexylcarbodiimide in dimethylformamide. The ethylcarbamoyl (Ec) protecting groups were removed by refluxing NH3, and the resulting disulfhydryl peptide was oxidatively cyclized to the corresponding disulfide by ICH2CH2I. Purification of the analog was effected by partition chromatography and gel filtration. The analog possesses antioxytocic (pA2 = 7.05) and antiavian vasodepressor (pA2 = 7.44) activities but has neither agonist nor antagonist activity in the rat pressor assay.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002645:Chickens; D003864:Depression, Chemical; D005260:Female; D066298:In Vitro Techniques; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000138:chemical synthesis / Q000494:pharmacology; D051381:Rats; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000494:pharmacology; D014443:Tyrosine / Q000138:chemical synthesis / Q000494:pharmacology; D014590:Uterine Contraction / Q000187:drug effects
D013438:Sulfhydryl Compounds; D014443:Tyrosine; D010121:Oxytocin