Wakeman—Pigments of Flowering Plants. 829 
2. ) Butein 
3. ) Anthocyanins. 
Pelargonidin 
Cyanidin 
Paeonidin 
Delphinidin 
Myrtillidin 
Malvidin 
Oenidin 
C. Diphenyl 1, 4, butene 2. 
Indigotin. 
I. A. Pigments referable to the diphenyl ethene series of 
hydrocarbons. 
1.) The only members of this series to which a plant pigment 
is referable is a methyl ethyl homologue, the tolyl-etho phenyl- 
ethene. 
Berberin, which is a basic plant pigment, an alkaloid, may be 
regarded as the product obtained by the deammoniation of a 
dimethyl, methylene either of a tetra hydroxy, triamido sub¬ 
stitution product of the above hydrocarbon. The accepted for- 
foirmula 1 for berberin is based upon the investigations of the 
products which result from the dbbau of the molecule by oxida¬ 
tion with potassium permangenate. 
Berberin was isolated by Buchner 2 before 1837 from the root 
of Berberis vulgaris and described by him. Since then it has 
been the subject of a large number of investigations and has 
1 Jr. Chem. Soc., 55, p. 63; 57, p. 992; 97, p. 318. 
2 Ann., 24 p. 228. 
