The biological action of chlorophenols.

The biological action of a series of chlorinated phenols has been investigated. With increasing chlorination there is an increase in toxicity in which the convulsant action of phenol is replaced by the signs characteristic of poisoning by dinitrophenol; the higher chlorinated phenols produce a contracture of the isolated rat phrenic nerve diaphragm and a stimulation of in vitro oxygen uptake of rat brain homogenate. These actions of the chlorinated phenols have been correlated with their dissociation constants; it is suggested that the higher chlorinated phenols interfere with oxidative phosphorylation, and that this property may be attributed to the chlorophenate ion. The convulsant action of the lower chlorinated phenols is probably associated with the undissociated molecule.