Aminoalkylindole analogs: cannabimimetic activity of a class of compounds structurally distinct from delta 9-tetrahydrocannabinol.

Abstract

Six novel aminoalkylindole analogs, related structurally to the dual cyclooxygenase inhibitor and nonopioid analgesic pravadoline, were evaluated in the mouse to determine whether their pharmacological profile of activity was similar to that exhibited by delta 9-tetrahydrocannabinol (delta 9-THC). Analog I (C2-H; C3-methoxy-benzoyl) reduced locomotion, but had no other effects (hypothermia, antinociception or ring-immobility) up to 21 mumol/kg. Analogs II and III (C3-naphthoyl; C2-H and C2-methyl, respectively) possessed all properties exhibited by delta 9-THC with ED50 values ranging from 0.68 to 18 mumol/kg. Analog IV (C2-methyl; C3-anthroyl) was devoid of activity. Stereoselectivity was demonstrated by the fact that (+)-WIN-55,212 (one isomer of a semirigid derivative possessing C2-H and C3-naphthoyl substituents) was moderately potent in all tests (ED50 values ranging from 0.25-23 mumol/kg), but (-)-WIN-55,212 was inactive up to 57 mumol/kg. Active aminoalkylindole compounds were generally least effective in the production of hypothermia. Analogs were also evaluated for their ability to produce delta 9-THC-like discriminative stimulus effects in rats. The ED50 for delta 9-THC as a discriminative stimuli for this model was 1.9 mumol/kg. Analog II and III and (+)-WIN-55,212 produced delta 9-THC-like discriminative effects with ED50 values ranging from 0.33 to 4.3 mumol/kg, whereas analogs I, IV and (-)-WIN-55,212 did not. Although reported to be cannabinoid receptor antagonists in vitro, neither analog I, analog IV nor (-)-WIN-55,212 (at 20 mumol/kg) antagonized the in vivo pharmacological effects of delta 9-THC in the mouse or rat.(ABSTRACT TRUNCATED AT 250 WORDS)