836 Wisconsin Academy of Sciences, Arts, and Letters. 
Hepthydroxides of Chalkon 
Tetrahydroxy-flavonols 
Quercetin 
Rhamnetin 
Isorhamnetin 
Rhamnazin 
Morin 
Octhydroxides of Chalkon 
Penthydroxy-flavanols 
Myricetin 
I. B. 1.) The Flavone Pigments. 
The flavone group constitutes the largest known group of 
plant coloring matters. All of its members are di-, tri-, tetra-, 
pent-, and hexhydroxy substitution products of flavone or 
methyl ethers of these substitution products. Flavone itself 
is a dehydration product of a hydroxy derivative of diphenyl -1, 
3-propene-l-one 3, (chalkone) 1 a compound which is yellow in 
color and the hydroxy derivatives of which (also yellow in color) 
have been used for the synthesis of practically of all of the mem¬ 
bers of this group. 
The flavone derivatives are all, as the name indicates, yellow 
in color. The intensity of the coloration appears to depend 
somewhat upon both the number and the position of the OH 
groups and varies from the pale yellow, or almost colorless, 
apigenin and acacetin to the deep orange yellow myricetin—a 
hexhydroxy flavone. 
The pigments belonging to this group are found in nearly all 
parts of the plant and both in the free condition and as glu- 
cosides. Chrysin, galangin, luteolin and kaempherid are re¬ 
ported as occuring only in the free state; quercetin, fisetin and 
kaempherol both as such and as glucosides, quercetin being 
found as the glucosides quercitrin, robinin, rutin, myticolorin, 
osyritrin. While luteolin is reported only in the free state, its 
(3) methyl ether occurs as glucoside in the leaves of parsley. 
All the other members of this group of coloring matters are re¬ 
ported as occurring potentially in the plant as glucosides, 
1 So called by Kostanecki to whose syntheses of the flavone coloring matters 
we are indebted for much of our knowledge of the structure of these com¬ 
pounds. 
