Analgesic and Sedative Effect of Thioureido Derivatives of Acetophenone Semicarbazones.

Several synthetic compounds like thiobisformamidine, dithiobiurets and thiobiurets posses a significant analgesic property (1). Some of them (isothiobiurets, thiobiurets) also potentiate the barbiturate hypnosis and this has generally been linked to an enhanced lipophilic property due to the introduction of sulphur. Partition coefficient (a lipophilic parameter for nvalue) is considered to influence the biological activity. Since acetaminophen is a suitable substitute of aspirin as far as analgesic/antipyretic property is concerned, a series of thioureido derivatives of acetophenone semicarbazones, that are closely related to acetaminophen, with an extra atom of sulphur incorporated in the molecule were synthesized (2). We describe here the analgesic properties of these compounds and their effect on the barbiturate induced hypnosis.