THE CONSTITUTION OF CALYCOPTERIN, THE YELLOW COLOURING MATTER OF THE LEAVES OF CALYCOPTERIS FLORIBUNDA

The constitution of calycopterin, the yellow colouring matter of the leaves of Calycopteris floribunda, is shown to be 5 :4'-dihydroxy-3 :6:7 :8-tetrametboxyflavone, since methylation with diazomethane under stated conditions gives a hydroxypenta­methoxyflavone, one hydroxyl thus resisting methylation. Further, the dimethyl ether of calycopterin could be partially demethylated to a hydroxypentamethoxyflavone