Abstract
The purgative activities of 18 different dihydroxyanthracene derivatives, including free anthraquinones and anthrones, were investigated by determining their influence on the water, sodium and potassium absorption in the gastrointestinal tract by direct injection of the solutions in Tyrode to the rat colon in situ. The extent of the solubility of the compounds has also been assessed. The 1,8-dihydroxyanthracene structure seemed to be the best for hydragogue effect. Rhein-anthraquinone and -anthrone were the most active compounds tested.