800 
Wisconsin Academy of Sciences, Arts, and Letters. 
Pigments referable to allyl benzene 
CH 
CH 
As will be seen from the structural formula, daphnetin may 
be looked upon as a dihydroxy cumarin, or as a product of the 
inner dehydration, a lactone, of tri-hydroxy cinnamic acid. 
Since the occurrence of daphentin in the plant is so frequently 
accompanied by that of cumarin, umbelliferone and other cin¬ 
namic acid derivatives, the importance of recognizing this rela¬ 
tionship cannot be over estimated. 
CH 
CH 
CH 
C CH : CH 
C-O—C=0 
Cumaric add 
CCH:CH HC 
C-O—c=o H0C 
C CH '.CH 
I 
c — o—c»o 
CH 
Cumarin 
CH 
Umbelliferone 
COH 
Daphnetin 
Daphnetin which is yellow in color, occurs in the yellow flow¬ 
ers of sweet clover, Mililotus officinalis. 1 .) together with cumarin, 
cumaric acid, and hydro cumaric 2 ) acid. The frequency of 
the occurrence of these and related compounds in this and other 
members of the Leguminosae will be taken up in the considera¬ 
tion of pigmentation in that family. 
Daphnetin, having two phenol hydrogens, is capable of form¬ 
ing metallic derivatives which may influence the color of the 
pigmented parts. With potassium it forms the socalled “semi- 
^erg. Jahresb., 14, 31 1 . 
3 Richter, II, p. 280. 
