PHENYL-SUBSTITUTED NORMETHADONES - SYNTHESIS AND PHARMACOLOGY

Phenyl-substituted normethadone derivatives were synthesized and their affinity (IC50) for opioid receptors was determined by displacement o f the specific binding sites of [H-3]sufentanyl on rat brain preparati ons. Substitution resulted in a decrease of affinity in-vitro. These r esults suggest that normethadone-like compounds may interact with the P subsite of the mu-opioid receptor and that the P subsite has a well- defined cavity shape of stringent dimensions.