Wakeman—Pigments of Flowering Plants. 797 
Methyl Kydroquinone occurs as the glueoside methyl arbutin 
in several species of Ericaceae. 21 ) It is also known to exist in 
several species of Pirola 22 ) and in Pirns communis , 23 ) 
Orcinol an isomer of methyl hydroquinone and referable to 
toluene is found in many lichens of the varieties Rocella and 
Lecenora. Orcinol 24 ) when allowed to stand exposed to air and 
ammonia forms orcein C 7 H 7 No 3 , the principal constituent of the 
coloring matter archil, called also persio, cudbear and nurpur. 
Azolithmin 25 ) C 7 H 7 No 4 , the coloring principle of litmus and an 
oxidation product of orcein, is also produced from these orcinol 
containing lichens by the action of ammonia and potassium 
carbonate. 
Pigments referable to trimethyl 1, 2, 4 benzene. 
CH, 
C 
CH, 
Q 
HC | H CH * 
HCj^\c-COOH 
Hcl OcH 
HOC ns. JcOH 
x/ 
c 
CH, 
C 
ch 3 
Trimethyl 1, 2, 4, benzene 
Methyl orsellinic acid 
In one variety of Rocella there occurs a homologue of erythrin 
known as betaerythrin. 26 ) This upon hy- 
bined to form the betaerythrin is therefore 
drolysis yields not orcinol but beta orcinol, 
or methyl orcinol, p-xylol orcinol. At 
least one molecule of the simple acids com- 
probably methyl orsellinic acid, referable 
to trimethyl 1, 2, 3 benzene. 
Ann., 206, 159; Ann., 177, 934. 
22 Am. J. Ph., 11, p. 549. 
23 Jr. Fharm. Chim., (7) 2, 248; C. r., 151, p. 444. 
24 Ann., 41, p. 157; 54, p. 261; 59, p. 72; Jr. Prakt. Chem., 44, p. 18; 
25 Ann., 39, p. 25; Czapek, Biochemie der Pflanzen, p. 508. 
2<J Czapek Brochemie der Pflanzen, p. 507. 
CH, 
Methyl orcinol 
