The conformation of the active cannabinoid Δ9-THC (I) as detd. by mol. reactivity characteristics was compared to that of the inactive compd. O-methyl-Δ9-THC (II). II was not able to mimic the conformation II of I in which the lone pairs of the phenol O are directed away from ring A. The relation of these results to the biol. activity of I is discussed. Other aspects of the conformation of cannabinoids are reviewed in relation to their biol. activity
