[Structure-activity relationship in the series of muscarinic acetylcholine receptor antagonists: four types of antagonist-receptor binding].

The data available in literature on the structure-activity relationships in the series of muscarinic antagonists have been analyzed. Three groups of the ammonium compounds are distinguished, each containing a specific chemical structure element. For the antagonist association with the receptor, the binding constant logarithms within each group depend linearly on the partition coefficient (pi) logarithms characterizing their distribution in the water-octanol system. The linear regression coefficients for pi are practically identical. A separate group consists of antagonists that have no ammonium grouping. Four possible modes of antagonist-receptor binding are surmized.