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XIII. 



DICHROMONE AND DIBENZYLDIGHEOMONE. 

 By JOSEPH ALGAE, D.Sc, EllANCIS FOGAETY, M.Sc, 



AND 



HUGH EYAN, D.Sc, 

 University College, Dublin. 



[Reail Febuuauy 11. Published Septemheu I.t, 1924.] 



The study of vegetable colouring matters during the past twenty-five years 

 has shown that many of these are related in structure, and may be referred 

 to the same parent type. 



Chrysin, apigenin, lotoflavin, luteolin, and scutellarein are all derived 

 from flavone ; butein from tlavanone ; and kaempferid, kaempferol, galangin, 

 quercetin, rhamne.tin, rhamnazin, fisetin, morin, myricetin, gossypetin, and 

 quercetagetin from flavonol. Again, the three substances, flavone, flavanone, 

 and flavonol, may in turn be regarded as derivatives of chromone : — 



Flavanone. 

 O 



Euxanthone and geutisin are derived from a benzochromone and brazilin 

 from a reduced chromone. Similarly, cyanidiu, delphinidin, and pelargonidin, 



R.I.A, PBGC, VOL. XXXVI, SECT. B. [2 Lj 



