Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxytocin (OT) was synthesized employing the solid phase method. Resins made of copolymers of polystyrene-1%-crosslinked with divinylbenzene gave better yields (73-95%) of Z-Cys(Bzl)-Tyr(Bzl)-Ile-Gln-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 (I) than 2%-crosslinked resins (10--56%). Reduction of I with Na-liq.NH3 and oxidation with I2-MeOH at -40 degrees minimized dimer and polymer formation, and resulted in good yields (49--54%) of OT. The large volumes of MeOH required when several grams of I are reduced and then oxidized were rapidly evaporated in vacuo, and the residue was desalted by dissolving the peptide in a small volume of glacial acetic acid and filtering to remove the salt. OT was purified by adsorption chromatography on a silica gel column with combinations of MeOH-CHCl3 of graded polarity. Oxytocin elutes with 33% MeOH-CHCl3. After two purification steps by adsorption chromatography, the resulting OT was found to be homogeneous. The hormone was characterized chemically and found to be active biologically.
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PMID:Synthesis of oxytocin using iodine for oxidative cyclization and silica gel adsorption chromatography for purification. 42 90

[1-Deaminopenicillamine,4-threonine]oxytocin was prepared in duplicate from S-benzyl-3-mercapto-3,3-dimethylpropanoyl-Tyr(Bzl)-Ile-Thr(Bzl)-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 (I) by removal of the Bzl-protecting groups with Na-NH3, followed by cyclization of the resulting disulfhydryl compound with K3Fo(CN)6. The analogue was purified by desalting on Sephadex G-15 in 50% acetic acid and gel filtration of Sephadex G-15. The protected peptide I was synthesized (a) by the solid-phase method and (b) by a combination of solid-phase synthesis and an [8 + 1] coupling in solution. The analogue has no detectable agonist activity in rat vasopressor or isolated rat uterus assays. It has an antivasopressor pA2 of 6.67 +/- 0.09. It is a potent inhibitor of the in vitro oxytocic response to oxytocin and has a pA2 value of 7.46 +/- 0.04. (Material from the repeat synthesis has a pA2 value of 7.59 +/- 0.08.) Thus the substitution of threonine for glutamine in the antagonist [1-deaminopenicilliamine]oxytocin (pA2, 7.14 +/- 0.05) has effected a twofold increase in inhibitory potency. [1-deaminopenicillamine,4-threonine]oxytocin is one of the most potent inhibitors of oxytocin known to date.
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PMID:[1-Deaminopenicillamine,4-threonine]oxytocin, a potent inhibitor of oxytocin. 62 12

[7-Thiazolidine-4-carboxylic acid)]oxytocin and [1-beta-mercaptopropionic acid,7-(thiazolidine-4-carboxylic acid)]oxytocin have been synthesized by a solid-phase method. Alpha-N-tert-Butoxycarbonyl- and S-ethylcarbamoyl-protecting groups were employed. The dipeptide Boc-Cys(Ec)-thiazolidine-4-carboxylic acid as well as individual residues was coupled to a H-Gly-dehydroalanine-resin with dicyclohexylcarbodiimide in the presence of 1-hydroxybenzotriazole. The appropriate protected polypeptide intermediates were cleaved from the resin by acidolysis, deprotected in NH3, and oxidized to the cyclic disulfide analogues with ICH2CH2I. Purification was effected by partition chromatography and gel filtration. Relative to oxytocin and [1-beta-mercaptopropionic acid]oxytocin, these analogues exhibit greatly enhanced oxytocic and avian vasodepressor potencies and unchanged rat pressor potencies.
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PMID:Synthesis and some pharmacological properties of oxytocin analogues having L-thiazolidine-4-carboxylic acid in position 7. 94 Jan 6

[1-Beta-mercapto-beta,beta-pentamethylenepropionic acid]oxytocin was prepared from beta-Mpa(beta-(CH2)5)(Bzl)-Tyr(Bzl)-Ile-Gln-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 by removal of the Bzl-protecting groups with Na-NH3 followed by cyclization of the resulting disulfhydryl compound with K3Fe(CN)6.The analog was purified by desalting on Sephadex G-15 in 50% HOAc and gel filtration on Sephadex G-25 and LH-20. The protected intermediate above was synthesized from Z-Cys(Bzl)-Pro-Leu-Gly-NH2 by the stepwose p-nitrophenyl ester method using Nalpha-Boc protection at the penta-, hexa-, and octapeptide stages. The analog was found to be a potent inhibitor of the oxytocic and avian vasodepressor effects of oxytocin (pA2 values of 7.43 and 8.30, respectively) but was only a weak inhibitor of the rat pressor effect of 8-lysine-vasopressin. The rat antipressor potency of [1-deaminopenicillamine]oxytocin was also determined in this study: pA2 = 6.27. Of the alkyl-substituted 1-position analogs of oxytocin studied so far, [1-beta-mercapto-beta,beta-pentamethylenepropionic acid]oxytocin is the most potent antioxytocic agent.
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PMID:[1-Beta-mercapto-beta,beta-pentamethylenepropionic acid]oxytocin, a potent inhibitor of oxytocin. 113 19

For the synthesis of [1-L-penicillamine,4-L-leucine]oxytocin (2), Z-Tyr(Bzl)-Ile-Leu-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 was treated with anhydrous HBr, and the resulting partially deprotected octapeptide was coupled with Z-penicillamine(Bzl) in a condensation reaction mediated by dicyclohexylcarbodiimide and 1-hydroxybenzotriazole. The protected nonapeptide Z-penicillamine(Bzl)-Tyr-Ile-Leu-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 was treated with Na in NH3 and the resulting disulfhydryl compound was subjected to oxidative cyclization in H2O-CH3OH with ICH2CH2I, Purification of 2 was effected by partition chromatography and gel filtration. The analog possesses antioxytocic and antiavian vasodepressor pA2 values of 6.77 and 7.21, respectively, and has no antipressor or anti-ADH activity. Its biological activity spectrum is qualitatively identical with that of [1-penicillamine]oxytocin. In contrast to the marked natriuretic-diuretic and anti-antidiuretic activity of [Leu4]oxytocin, 2 exhibits none of these effects on the rat kidney.
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PMID:Synthesis and pharmacological properties of [1-L-penicillamine,4-L-leucine]oxytocin. 115 79

[4-Phenylalanine]oxytocin was prepared from Z-Cys(Bzl)-Tyr(Bzl)-Ile-Phe-Asn-Cys(Bzl)-Pro-Leu-Gly-NG2 (4) by deprotection with Na in NH3 followed by cyclization of the resulting disulfhydryl compound with ICH2CH2I. The protected peptide 4 was prepared from Boc-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 by the stepwise solution method. Coupling was effected by a modification of the dicyclohexylcarbodiimide-1-hydroxybenzotriazole preactivation method wherein the precipitate of dicyclohexylurea is removed by filtration prior to mixing of the amino and carboxyl components. The analog was found to be an effective inhibitor of the antidiuretic (ADH) response to exogenous arginine-vasopressin. It produced marked diuresis in the anti-ADH assay at approximately the same dose level as does [Leu4]oxytocin but, in contrast to [Leu4]oxytocin, showed natriuretic activity only at relatively high dose levels. In addition, [Phe4]oxytocin exhibited 0.15% of the oxytocic potency of oxytocin, weak antiavian vasodepressor activity (pA2 = 6.93), and no measurable rat pressor activity.
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PMID:(4-Phenylalanine)oxytocin, an inhibitor of the antidiuretic effect of 8-arginine-vasopressin. 115 80

[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.
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PMID:(1-Beta-mercaptopropionic acid, 2-(3,5-dibromo-L-tyrosine))oxytocin, a potent inhibitor of oxytocin. 115 88

The synthesis of the protected polypeptide precursor of [1-beta-mercapto-beta,beta-diethylpropionic acid,2-(3,5-dibromo-L-tyrosine)]oxytocin was performed in a stepwise manner by solution techniques. This analog of oxytocin has two modifications, each of which taken alone gives analogs which inhibit some of the pharmacological responses to oxytocin. The S-ethylcarbamoyl protecting groups of beta-Mpa(beta-Et2)(Ec)-Dbt-Ile-Gln-Asn-Cys(Ec)-Pro-Leu-Gly-NH2 were removed in refluxing liquid NH3, and the resulting disulfhydryl compound was oxidatively cyclized in H2O-MeOH with ICH2CH2I. Purification was effected by partition chromatography and gel filtration. The analog possesses antioxytocic (pA2 = 7.08) and antiavian vasodepressor (pA2 = 7.38) activities but has neither agonist nor antagonist activity in the rat pressor assay. These potencies are close to those exhibited by [1-beta-mercaptopropionic acid,2-(3,5-dibromo-L-tyrosine)]oxytocin but different from those of [1-beta-mercapto-beta,beta-diethylpropionic acid]oxytocin.
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PMID:Synthesis and some pharmacological properties of [1-beta-mercapto-beta,beta-diethylpropionic acid,2-(3,5-dibromo-L-tyrosine)]oxytocin. 119 81

Five analogs of oxytocin have been synthesized with a homocysteine residue in position 6 and 2-, 3-, or 4-carbon residues in position 1. The compounds, which contain 20-, 21-, and 22-membered disulfide rings, respectively, were [1-alpha-mercaptoacetic acid,6-homocysteine]oxytocin, [6-homocysteine]oxytocin, [1-beta-mercaptopropionic acid,6-homocysteine]oxytocin, [1,6-homocystine]oxytocin, and [1-gamma-mercaptobutyric acid,6-homocysteine]oxytocin. The appropriate protected polypeptide intermediates were prepared by the solid-phase method of peptide synthesis. The protecting groups were removed by treatment with Na in NH3 and the disulfide bond was formed by oxidation with ICH2CH2I in aqueous MeOH. Purification was effected by partition chromatography followed by gel filtration. The pharmacological activities of all five analogs are reported for the oxytocic, avian vasodepressor, and rat pressor assays. Compared to oxytocin, these analogs exhibited sharply reduced agonist potencies, and several exhibited antagonist acitivty.
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PMID:Synthesis and some pharmacological properties of five analogs of oxytocin having L-homocysteine in position 6. 124 4

As part of a program in which we are attempting (a) to delineate the structural features at positions 1-9 in our previously reported antidiuretic antagonists required for antidiuretic antagonism and (b) to obtain analogues with enhanced antiantidiuretic potency and/or selectivity, we have synthesized 14 new analogues of the antidiuretic antagonist [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid),2-D-phenylalanine,4-valine]arginine-vasopressin [d-(CH2)5-D-Phe2VAVP), in which the valine residue at position 4 was replaced by the following L-amino acids and glycine: Ile, Abu, Thr, Ala, Gln, Lys, Cha, Nle, Nva, Phe, Leu, Gly, Tyr, and Pro. These analogues are 1, d-(CH2)5-D-Phe2,Ile4AVP; 2, d(CH2)5-D-Phe2,Abu4AVP; 3, d(CH2)5-D-Phe2,Thr4AVP; 4, d(CH2)5-D-Phe2,Ala4AVP;5, d(CH2)5-D-Phe2AVP; 6, d(CH2)5-D-Phe2,Lys4AVP; 7, d(CH2)5-D-Phe2,Cha4AVP; 8, d(CH2)5-D-Phe2,Nle4AVP; 9, d(CH2)5-D-Phe2,Nva4AVP; 10, d(CH2)5-D-Phe2,Phe4AVP; 11, d(CH2)5-D-Phe2,Leu4AVP; 12, d(CH2)5-D-Phe2,Gly4AVP; 13, d(CH2)5-D-Phe2,Tyr4AVP; 14, d(CH2)5-D-Phe2,Pro4AVP. The protected intermediates required for the synthesis of all of these peptides were prepared by the solid-phase method and cleaved from the resin by ammonolysis. Following deblocking with Na in NH3 and oxidizing with K3[Fe(CN)6], each peptide was purified on Sephadex G-15 in a two-step procedure using 50% HOAc and 0.2 M HOAc as eluants. Analogues 1-14 were tested for agonistic and antagonistic activities by antidiuretic, vasopressor, and oxytocic assays in rats. Analogues 1, 2, and 4-6 exhibit no detectable antidiuretic agonistic activity. All analogues, with the exception of the Pro4-containing analogue, are antidiuretic antagonists. Their antiantidiuretic pA2 values are as follows: 1, 8.24 +/- 0.08; 2, 7.96 +/- 0.07; 3, 7.62 +/- 0.09; 4, 7.52 +/- 0.03; 5, 7.21 +/- 0.07; 6, 7.22 +/- 0.12; 7, 7.19 +/- 0.08; 8, 7.12 +/- 0.09; 9, 6.99 +/- 0.06; 10, 6.07 +/- 0.11; 11, 6.07 +/- 0.11; 12, 5.85 +/- 0.05; 13, approximately 5.57; 14, a weak agonist (0.004 U/mg). Analogues 1-14 also antagonize the vascular responses to arginine-vasopressin (AVP) and the in vitro oxytocic responses to oxytocin. Analogues 1, 2, 3, and 5 have also been shown to antagonize the in vivo oxytocic responses to oxytocin. Five of these analogues (1, 2, 3, 6, and 7) exhibit enhanced antiantidiuretic/antivasopressor selectivity. d(CH2)5-D-Phe2,Lys4AVP and other position-4 analogues with side-chain functional groups may be useful covalent ligands with which to probe the structural characteristics of AVP renal and vascular receptors. With an antiantidiuretic "effective dose" of 0.46 +/- 0.07 nmol/kg and a pA2 value of 8.24 +/- 0.08, d(CH2)5-D-Phe2,Ile4AVP (1) appears to be the most potent antidiuretic antagonist reported to date.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Potent antagonists of the antidiuretic responses to arginine-vasopressin based on modifications of [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid),2-D- phenylalanine,4-valine]arginine-vasopressin at position 4. 663 16


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