92780-94-4Relevant academic research and scientific papers
Structure-Activity Relationships for the Competitive Angiotensin Antagonist 1,O-methyltyrosine4>angiotensin II (Sarmesin)
Goghari, Mahesh H.,Franklin, Kevin J.,Moore, Graham J.
, p. 1121 - 1124 (2007/10/02)
Analogues of the competitive angiotensin antagonist 1,Tyr(Me)4>ANG II (sarmesin) in which the sarcosine-1, O-methyltyrosine-4, and phenylalanine-8 residues were modified have been synthesized by the solid-phase method.The agonist and antagonist potencies of the 23 peptides synthesized were determined in the rat isolated uterus assay.At position 1, replacement of Sar with Asp, Ala, or Pro gave inactive analogues, and deletion of the N-terminal amino acid produced inactive heptapeptides for all analogues investigated.At position 4, substitution of Tyr with Tyr(Et), D-Tyr, D-Phe, Ile, Thr, or Hyp resulted in inactive analogues, whereas substitution of Phe gave a potent competitive antagonist (pA2 = 7.9), which retained significant agonist activity (22percent).For position 8, 1,Tyr(Me)4,Ile8>ANG II and 1,Phe4,Ile8>ANG II were weaker antagonists (pA2 = 6.6 and 6.7, respectively) than 1,Ile8>ANG II (pA2 apparent = 8,1) and moreover, were reversible competitive antagonists.These findings demonstrate that the structural requirements for receptor blockade by sarmesin are remarkably stringent-modifications at positions 1, 4, and 8 markedly reduce the antagonist activity of this peptide.
Synthesis and Biological Activities of Analogues of Angiotensins II and III Containing O-Methyltyrosine and D-Tryptophan
Matsoukas, John M.,Goghari, Mahesh H.,Scanlon, Martin N.,Franklin, Kevin J.,Moore, Graham J.
, p. 780 - 783 (2007/10/02)
Analogues of angiotensin II and III (ANG II and ANG III) in which the tyrosine and/or phenylalanine residues were substituted have been synthesized by the solid-phase method and purified by (carboxymethyl)cellulose chromatography and reversed-phase HPLC.The antagonist and agonist potencies of these peptide were determined in the rat isolated uterus assay. 1,Tyr(Me)4>ANG II, 3>ANG III, 1,D-Trp4>ANG II, 3>ANG III, 1,D-Trp8>ANG II, 7>ANG III, 1,Tyr(Me)4,Ile8>ANG II, 3,Ile7>ANG III, 1,D-Trp4,Ile8>ANG II, 3,Ile7>ANG III, 1,Tyr((Me)4,D-Trp8>ANG II, and 3,D-Trp7>ANG III had antagonist activities (pA2) respectively of 8.1, a single aromatic residue substitution.Substitution of the Tyr residue in ANG II, but not ANG III, provides a new route for the synthesis of potent and competitive angiotensin antagonists.Differences in the biological properties of ANG II and ANG III analogues substituted at the Tyr residue suggest different binding/conformation requirements for the two endogenous ligands at angiotensin receptors in smooth muscle.
