Science, Vol 220, Issue 4595, 417-418
Copyright © 1983 by American Association for the Advancement of Science
Methadone conformation and opioid activity
WL Duax,
GD Smith,
JF Griffin,
and
PS Portoghese
The inactive methadone analog threo-5-methylmethadone has a solid-state conformation in which the nitrogen is antiperiplanar to the tertiary carbon C(4). Since threo-5-methylmethadone exhibits no opioid agonism either in vivo or in vitro, methadone analogs probably do not have this conformation when bound to an opioid receptor. The potent agonist (-)-erythro-5-methylmethadone has a solid-state conformation in which the nitrogen atom is rotated back toward the phenyl rings on the quarternary carbon, suggesting that this unusual conformation is the active one.