Some pharmacological investigations of embelin and its semisynthetic derivatives.

Embelin, obtained from Embolin ribes was condensed with different primary amines. Depending on the conditions of reaction, disalts or diimines were formed. Ten such disalts and fourteen diimines were developed. Embelin and all its disalts showed analgesic activity whereas all the diimines derivatives were inactive. The disalt, 2:5 disobutyl amine embelin showed maximum action. Analgesic effect was noticed only after intraperitoneal administration but not after subcutaneous, intramuscular or oral administration. The compounds cause some local irritation. The possibility of peritoneal irritation rendering the animals unresponsive to experimental pain seems to deserve consideration. However, analgesic effect could be seen in dogs and cats after intravenous injection. Embelin and its disalt, 2:5 isobutyl amine embelin also exhibited antipyretic and antiinflammatory activities.