Title: Orcein
CAS Registry Number: 1400-62-0
Literature References: A dye first prepared from lichens (cudbear,
q.v., or
archil). Prepn by oxidation of orcinol with H2O2 in the presence of ammonia water: Zulkowski, Peters,
Monatsh. Chem. 11, 227 (1890). Can be separated into 14 dyes by distribution chromatography: Musso,
Ber. 89, 1659 (1956). The eight compds depicted are the major components of orcein; b- and g-components are
cis-trans isomers of the same compd. Structure studies: Beecken
et al., Angew. Chem. 73, 665 (1961). Brief review:
H. J. Conn's Biological Stains, R. D. Lillie, Ed. (Williams & Wilkins, Baltimore, 9th ed., 1977) pp 400-403. Review of use as textile dye and histological stain for elastin: H. Puchter, S. N. Meloan,
Histochemistry 64, 119 (1979).
Properties: Brownish-red microcryst powder. Practically insol in water, benzene, chloroform, ether, carbon disulfide. Sol in alcohol, acetone or acetic acid with red color, in dil aq alkali with bluish-violet color.
Use: Biological stain.
