Wakeman—Pigments of Flowering Plants . 807 
Pigments referable to phenyl-dihydro phenyl methane. 
CH 
CH 
„c/\ 
he — CH,- 
1 
O 
Vh, 
[IcH 
hcL 
/CH, 
CH 
CH 
Phenyl-dihydro phenyl-methane 
COH 
CH 
j) c * — 
-c/\ 
^CH, 
HC \y 
jJc— o- 
"A/ 
JcH, 
COH 
Rhamnocitrin 
CH 
» of yellow pigments, some of them supposedly de- 
rivatives of the above named hydrocarbon, has been isolated from 
the berries of Rhamnus cathartica . 7 ) These pigments are rham- 
nocitrin, /3-rhamnocitrin, rhamnochrisin, rhamnolntin and 
rhamnonigrin. As will be seen from the formula assigned to 
rhamnocitrin above, these pigments resemble the xanthone de¬ 
rivatives, falling under the degree of saturation Cn H 2n — i4 , 
more closely than they do the remaining known pigments of 
this degree of saturation. They are indeed derivatives of a 
reduced xanthone nucleus. 
Rhamnocitrin occurs, probably, in the free state. It cry¬ 
stallizes in golden yellow needles, and it forms metallic deriva¬ 
tives deeper in color than the compound itself. 
/3-Rhamnocitrin has the same empirical formula as rham¬ 
nocitrin which it closely resembles. To mordanted fabrics it 
imparts a more enduring color than does rhamnocitrin. 
Rhamnochrysin, C 1S H 12 0 7 crystallizes in orange yellow cry¬ 
stals. It is looked upon as an oxidation product of rhamno¬ 
citrin. Whether the molecule is of phenyl-dihydro phenyl 
7 Bull, de Pharm., 4, p. 64; Journ. de Chim., Med., 6, p. 193; Journ. de 
Pharm., et de Chim., 11, p. 666; Arch, de Pharm., 113, p. 63 ; Arch, d 
Pharm., 238, p. 459. 
