Quantitative structure-activity studies on hallucinogenic mescaline analogs using modified first order valence connectivity.

Attempt is made to correlate the hallucinogenic activity of a series of mescaline analogs with Kier's molecular connectivity index (chi). In order to find a simpler and more meaningful correlation, a little modification is suggested to the first-order valence connectivity index (1 chi upsilon). The modification is found to reveal utterly simple but significant correlations between activity and 1 chi upsilon, which could describe the structural influence on the activity more vividly.