Hallucinogenic activity, correlation with

Our goal in this discussion is to present the types of structural variations that have been studied in the various classes of hallucinogens and to explain how these changes affect biologic activity. Where possible, reasonable explanations for these differences are offered. Since we are just beginning to scratch the surface in our search for useful structure-activity relationships, the reader will soon note that most of the correlations are empirical, with no readily apparent biochemical or pharmacologic rationale. 

Partitioning into the CNS will be important for hallucinogens, as for any drug that acts centrally. Correlation between 1-octanol/water partition coefficients and human activity has been reported (13). Regression analysis of log human activity on log P yielded a parabolic fit with an optimum at log P 3.14. The derived equation accounted for only 62% of the variance but included compounds with a variety of substitution patterns and, presumably, qualitative differences in activity. 

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