Impact of hydroxy moieties at the benzo[7]annulene ring system of GluN2B ligands: Design, synthesis and biological evaluation.
Bioorg Med Chem
; 27(23): 115146, 2019 12 01.
Article
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| MEDLINE
| ID: mdl-31648876
ABSTRACT
In this study, the impact of one or two hydroxy moieties at the benzo[7]annulene scaffold on the GluN2B affinity and cytoprotective activity was analyzed. The key intermediate for the synthesis of OH-substituted benzo[7]annulenamines 11-13 and 17 was the epoxyketone 8. Reductive epoxide opening of 8 resulted with high regioselectivity in the 5-hydroxyketone 9 (Pd(OAc)2, HCO2H, phosphane ligand) or the 6-hydroxyketone 10 (H2, Pd/C), whereas hydrolysis in aqueous dioxane led to the dihydroxyketone 14. Reductive amination of these ketones with primary amines and NaBH(OAc)3 afforded the benzo[7]annulenamines 11-13 and 17. In receptor binding studies 5-OH derivatives 11 and 12 showed higher GluN2B affinity than 6-OH derivatives 13, which in turn were more active than 5,6-di-OH derivative 17a. The same order was found for the cytoprotective activity of the ligands. The tertiary amine 12a with one OH moiety in 5-position represents the most promising GluN2B negative allosteric modulator with a binding affinity of Kiâ¯=â¯49â¯nM and a cytoprotective activity of IC50â¯=â¯580â¯nM. In the binding pocket 12a shows a crucial H-bond between the benzylic OH moiety and the backbone carbonyl O-atom of Ser132 (GluN1b). It was concluded that a 5-OH moiety is essential for the inhibition of the NMDA receptor associated ion channel, whereas a OH moiety in 6-position is detrimental for binding and inhibition. An OH or CH2OH moiety at 2-position results in binding at the ifenprodil binding site, but very weak ion channel inhibition.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Compuestos Bicíclicos con Puentes
/
Receptores de N-Metil-D-Aspartato
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Bioorg Med Chem
Asunto de la revista:
BIOQUIMICA
/
QUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Alemania