Orcein and litmus.
Orcein was separated into 14 dyes by partition chromatography. Their constitutions were determined mainly by spectroscopy and led to formulae that are derived from 7-amino-2-phenoxazone, 7-hydroxy-2-phenoxazone, and 7-amino-2-phenoxazime, and that were confirmed by syntheses. The major constituent of litmus is assembled polymerically from 7-hydroxy-2-phenoxazone chromophores. The mechanism of formation is elucidated.
Beecken
H
H
Organic Chemistry Institute, University of Göttingen, Göttingen, Germany.
Gottschalk
E-M
EM
v Gizycki
U
U
Krämer
H
H
Maassen
D
D
Matthies
H-G
HG
Musso
H
H
Rathjen
C
C
Zdhorszky
Ul
U
D004396:Coloring Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D016591:Histocytological Preparation Techniques; D008011:Lichens / Q000737:chemistry; D010078:Oxazines / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification
D004396:Coloring Agents; D010078:Oxazines; C020456:phenoxazinone; C002313:PAcein