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.
Organic Chemistry Institute, University of Göttingen, Göttingen, Germany.
H
H
Beecken
E-M
EM
Gottschalk
U
U
v Gizycki
H
H
Krämer
D
D
Maassen
H-G
HG
Matthies
H
H
Musso
C
C
Rathjen
Ul
U
Zdhorszky
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