Muscarinic receptor binding activity of polyoxygenated flavones from Melicope subunifoliolata

Six polymethoxyflavones [melibentin (1); melisimplexin (3); 3,3′,4′,5,7-pentamethoxyflavone (4); meliternatin (5); 3,5,8-trimethoxy-3′,4′,6,7-bismethylenedioxyflavone (6); and isokanugin (7)] and one furanocoumarin [5-methoxy-8-geranyloxypsoralen (2)] were isolated. Compounds 2 and 6 were isolated for the first time from Melicope subunifoliolata. The muscarinic receptor binding activities of these compounds were investigated.