Tyr-Tic-Phe

The first known example of a mixed p agonist/5 antagonist was a TIPP analogue in which the free C-terminal carboxylate function had been replaced by a carboxamide function [37]. This compound, H-Tyr-Tic-Phe-... 

Wilkes BC, Schiller PW. Theoretical conformational analysis of the opioid 6 antagonist H-Tyr-Tic-Phe-OH and the p agonist H-Tyr-D-Tic-Phe-NH2. Biopolymers 1994 34 1213-1219. 

Wilkes BC, Nguyen TM-D, Weltrowska G, Carpenter KA, Lemieux C, Chung NN, Schiller PW. The receptor-bound conformation of H-Tyr-Tic-(Phe-Phe)-OH related -opioid antagonists contains all trans peptide bonds. J Peptide Res 1998 51 386-394. 

The geometric isomers 464 and 467 of 5(47/)-oxazolones prepared from acetophenones can be separated. Alternatively, the mixture can be isomerized under the appropriate reaction conditions to obtain the pure of (Z) or ) isomer. Each isomer can be converted to a pair of enantiomers 466 and 469 (only one enantiomer shown) (Scheme 7.152). The p-methyl phenylalanine analogues thus obtained are constrained phenylalanines and the effect of incorporation of a p-MePhe or p-MeTyr residue on the biological properties of H-Tyr-Tic-Phe-Phe-NH2 (TIPP, where Tic = l,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) a delta opioid receptor antagonist, has been studied. ... 

The first known compound with a mixed p-agonist/6-antagonist profile was the tetrapeptide amide H-Tyr-Tic-Phe-Phe-NH2 (TIPP-NH2) [27] (Table 3). TIPP-NH2 was a moderately potent p-agonist in the GPI assay and a potent 6 antagonist in the MVD assay. It showed some 6- versus p-receptor... 

Further studies in mouse vas deferens indicated that DPI-3290 is also active at mu opioid receptors. The intrinsic activity of DPI-3290 at mu opioid receptors was determined in the presence of the highly selective delta opioid receptor antagonist TIPP (H-Tyr-Tic-Phe-Phe-OH) (3 pM) and the selective kappa opioid receptor antagonist nor-BNI (15 nM). Under these conditions, DPI-3290 again caused concentration-dependent inhibition of muscle contraction with a corresponding IC50 value of 6.2 2.0 nM. Although far less potent at kappa opioid receptors in comparison to its intrinsic activity at mu... 

Tyr-Tic-Phe-Phe-OH TIPPpP] Tyr-TicPsi[CH2NH]Phe-Phe-OH (-)U-50, 488 tra s-3,4-dichloro-N-methyl-N-[2-(l-pyrrolidinyl)-cyclohexyl]-ben-zeneacetamide U-69,593 (5a, 7a, 8a)-(-)-N-methyl-N-(7-(l-pyrrolidinyl-l-oxaspiro(4.5)dec-8yl)benzeneacetamide. 

Representative peptides acting as delta opioid receptor antagonists, including Tyr-Tic-Phe-Phe-OH (TIPP), Tyr-D-Tic-Phe-Phe-NH2... 

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