98569-15-4

Upstream product

• 144646-02-6 3',4'-dihydro-6'-methoxyspiro-2,5-dione 
• 35581-10-3 2-amino-1,2,3,4-tetrahydro-6-methoxynaphthalene-2-carboxylic acid 
• 267660-41-3 N-trifluoroacetyl-6-methoxy-2-aminotetralin-2-carboxylic acid 

Relevant academic research and scientific papers

Deltorphin II analogues with 6-hydroxy-2-aminotetralin-2-carboxylic acid in position 1

Two approaches to the design of very active and highly selective δ opioid peptides were used to obtain new deltorphin analogues with altered hydrophobic and stereoelectronic properties. Deltorphin II analogues were synthesized with the substitution of Ile instead of Val at positions 5 and 6 in the address domain and 6-hydroxy-2-aminotetralin-2-carboxylic acid (Hat) instead of Tyr1 in the message domain. In the radioreceptor-binding studies, in which type-specific tritiated opioid ligands were used, (R)- and (S)-Hat- deltorphins exhibited similar K(i) values, revealing high δ selectivity. The peptides displayed agonist properties in the in vitro bioassay, with IC50 values in the subnanomolar range in the mouse vas deferens assay and in the micromolar or higher range in the guinea pig ileum assay, again demonstrating a high selectivity toward δ receptors. The agonist property of the new ligands was confirmed by means of [35S]GTPγS-binding experiments in membranes of the rat frontal cortex.

Novel open-chain and cyclic conformationally constrained (R)- and (S)-α,α-disubstituted tyrosine analogues

A series of novel open-chain and cyclic conformationally constrained (R)- and (S)-α,α-disubstituted tyrosine analogues 1a-e were synthesized in good yields and high optical purities. The absolute configurations of these tyrosine analogues were unambiguously determined based on the X-ray structures of the precursor diastereoisomeric peptides of type 4 and 5. Four of these structures are deseribed, showing β-turn type-I geometries for dipeptides 4b, 5b, and 4c and an extended conformation for peptide 5c. The conversion of the free amino acids 1a-c into suitably protected building blocks 11a-d and 15d,e for peptide synthesis is discussed.