Dehydrodicaffeic acid dilactone, an inhibitor of catechol-O-methyl transferase

In the screening of catechol-O-methyltransferase inhibitors, three compounds were isolated from the culture filtrate of a mushroom, Inonotus sp. One was 3,4-dihydroxycinnamic acid (caffeic acid) which had been reported as an inhibitor of this enzyme. The others were the dextrorotatory 2,6-bis-(3',4'-dihydroxyphenyl)-3,7-dioxabicyclo-[3,3,0]-octane 4,8-dione (dehydrodicaffeic acid dilactone) andits antipode. These new compounds inhibited both dopamine beta-hydroxylase and dopa decarboxylase and showed hypotensive activity in the SH rat.