Redefining the structure–activity relationships of 2,6-methano-3-benzazocines. Part 2: 8-formamidocyclazocine analogues
摘要:
High affinity binding for p and K opioid receptors has been observed in analogues of cyclazocine, ethylketocyclazocine and naltrexone where the prototypic (of opiates) phenolic OH group was replaced with a formamide (-NHCHO) group. For the 8-formamide analogue of cyclazocine, binding is highly enantiospecific (eudismic ratios similar to2000 for mu and kappa) with K-i values less than or equal to 1 nM observed for the (2R,6R, 11R)-isomer, (-)-4. A preliminary SAR revealed that affinity is very sensitive to substitution on the formamide appendage. (C) 2003 Elsevier Science Ltd. All rights reserved.