Synthesis and Analgesic Activity of Annelated Xanthine Derivatives in Experimental Models in Rodents

A series of annelated derivatives of xanthine were synthesized and assayed as potential analgesic agents. All synthesized xanthine derivatives were tested in the writhing test and hot-plate test. The pharmacological assays demonstrated that all the compounds prepared, without exception, displayed a significant activity in the mouse writhing assay. The analgesic action of the most active compounds, expressed as ED50 was found to be 1.4-4.3 times more potent than that of acetylsalicylic acid used as the reference compound. However, only some of the compounds demonstrated analgesic activity in the hot-plate test. The analgesic effect of some compounds is probably related to their agonistic, antagonistic, or partial agonistic activity at the adenosine receptors.