Normorphine

Normorphine is an opiate analogue, the N-demethylated derivative of morphine, that was first described in the 1950s when a large group of N-substituted morphine analogues were characterized for activity.

Normorphine has relatively little opioid activity in its own right, but is a useful intermediate which can be used to produce both opioid antagonists such as nalorphine, and also potent opioid agonists such as N-phenethylnormorphine. It is also produced as a major metabolite of morphine, with its formation from morphine catalysed by the liver enzymes CYP3A4 and CYP2C8.