Synthesis and anti-platelet, anti-inflammatory and anti-allergic activities of methoxyisoflavanquinone and related compounds

In a continuation of our search for novel anti-platelet agents, isoflavone quinone and isoflavanquinone were selected as lead compounds and the synthe sis of their methoxy derivatives was carried out, Among them, the 4'- and 7 -methoxy derivatives were successfully prepared, whereas the attempt to obt ain 3'-methoxy derivatives resulted in their isomers, 3'-methoxyflavone qui none and 3'-methoxyflavanquinone, instead. After screening for their anti-platelet anti-inflammatory and anti-allergic activities, a preliminary structure-activity relationship was established. Compounds 6c. 7a-c, 8c and 9a-c were found to exhibit significant activitie s. In particular, compound 7c demonstrated very potent anti-platelet, anti- inflammatory and anti-allergic activities and was then recommended for furt her pharmacological investigation.