ORCHIL

CAS NO:1400-62-0
EC NO:215-750-6

Orchil, also archil, orchil, lacmus and C.I. Natural Red 28, are names for dyes extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria.
Orchil is extracted from such lichens. 
Orchil is then converted to orcein by ammonia and air. In traditional dye-making methods, urine was used as the ammonia source. If the conversion is carried out in the presence of potassium carbonate, calcium hydroxide, and calcium sulfate (in the form of potash, lime, and gypsum in traditional dye-making methods), the result is litmus, a more complex molecule.The manufacture was described by Cocq in 1812 and in the UK in 1874.Edmund Roberts noted orchilla as a principal export of the Cape Verde islands, superior to the same kind of "moss" found in Italy or the Canary Islands, that in 1832 was yielding an annual revenue of $200,000.: pp.14, 15  Commercial archil is either a powder (called cudbear) or a paste. 
Orchil is red in acidic pH and blue in alkaline pH.

History and uses:
The chemical components of orcein were elucidated only in the 1950s by Hans Musso.The structures are shown below. A paper originally published in 1961, embodying most of Musso's work on components of orcein and litmus, was translated into English and published in 2003 in a special issue of the journal Biotechnic & Histochemistry (Vol 78, No. 6) devoted to the dye. A single alternative structural formula for orcein, possibly incorrect, is given by the National Library of Medicine and Emolecules.

Orchil is a reddish-brown dye, orchil is a purple-blue dye. Orchil is also used as a stain in microscopy to visualize chromosomes, elastic fibers, Hepatitis B surface antigens,and copper-associated proteins.

Orchil is not approved as a food dye (banned in Europe since January 1977), with E number E121 before 1977 and E182 after.
Orchils CAS number is 1400-62-0. 
Orchils chemical formula is C28H24N2O7. 
Orchil forms dark brown crystals. 
Orchil is a mixture of phenoxazone derivates - hydroxyorceins, aminoorceins, and aminoorceinimines.

Orchil is a member of the class of benzofurans that is dibenzo[b,d]furan-3,7-dione bearing two methyl substituents at positions 1 and 9 as well as two 2,4-dihydroxy-6-methylanilino substituents at positions 2 and 8. 
Orchil is a member of dibenzofurans, a polyphenol, a member of resorcinols, a secondary amino compound and a member of quinomethanes.

Orchil definition, a red dye, the principal coloring matter of cudbear and orchil, obtained by oxidizing an ammoniacal solution of orcinol.

Orchil is a red dye used in microscopy as a mordant for the staining of flagella, as well as for detecting elastic tissue in sputum.

Appearance :Powder
Physical State :solid
Solubility :Soluble in acetone, alcolhol, acetic acid (red color), and dillute aqueous alkali (blue-violet color). Insoluble in water.
Storage :Store at room temperature
Boiling Point :~779.0° C at 760 mmHg (Predicted)
Density :~1.6 g/cm3 (Predicted)
Refractive Index :n20D 1.76 (Predicted)
pK Values :pKa: 9.27 (Predicted), pKb: 0.99 (Predicted)

Orchil is a red dye used in microscopy as a mordant for the staining of flagella, as well as for detecting elastic tissue in sputum.

Orchil (cas# 1400-62-0) is an organic dye and histochemical stain. 
Orchil has also been used as a stain for extracellular matrices. Dyes and metabolites.

Chemical Properties    
dark brown crystals or powder

Uses    
Biological stain.

Uses    
Orchil (cas# 1400-62-0) is an organic dye and histochemical stain. 
Orchil has also been used as a stain for extracellular matrices. Dyes and metabolites.

Definition    
ChEBI: A member of the class of benzofurans that is dibenzo[b,d]furan-3,7-dione bearing two methyl substituents at positions 1 and 9 as well as two 2,4-dihydroxy-6-methylanilino substituents at positions 2 and 8.

General Description    
Orchil is a weakly acidic orange-red fluorochrome and is mainly required for the staining of elastic tissue. 
Orchil is not specific for chromatin staining, however, in acidic solutions it works as a basic dye and stains basophilic chromosomes purple red.

Specifications:
Appearance (Colour):    Reddish-violet
Appearance (Form):    Powder
Loss on drying:    max. 7%
Absorbance: (A) of 1% in 0.01M NaOH in a 1cm cell    
@580nm    min. 600

IUPAC names
2,8-bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethyldibenzo[b,d]furan-3,7-dione
Orchil
Orchil (Synthetic)

SYNONYMS:
2,8-bis(2,4-dihydroxy-6-methylanilino)-1,9-dimethyldibenzo[b,d]furan-3,7-dione
2,8-Bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethyldibenzo[b,d]furan-3,7-dion [German] [ACD/IUPAC Name]
2,8-Bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethyldibenzo[b,d]furan-3,7-dione [ACD/IUPAC Name]
2,8-Bis[(2,4-dihydroxy-6-méthylphényl)amino]-1,9-diméthyldibenzo[b,d]furane-3,7-dione [French] [ACD/IUPAC Name]
3,7-Dibenzofurandione, 2,8-bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethyl- [ACD/Index Name]
Pacein
14005-14-2 [RN]
1400-62-0 [RN]
2,2-Dimethyl-1,3-benzodioxole [ACD/IUPAC Name]
2,8-Bis(2,4-dihydroxy-6-methylanilino)-1,9-dimethyldibenzofuran-3,7-dione
2,8-bis(2,4-dihydroxy-6-methylphenylamino)-1,9-dimethyldibenzo[b,d]furan-3,7-dione
2,8-bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethylbenzo[1,2-b]benzo[1,2-d]furan-3,7-dione
2,8-bis[(2,4-dihydroxy-6-methylphenyl)amino]-1,9-dimethyldibenzofuran-3,7-dione
215-750-6 [EINECS]
220751-92-8 [RN]
4,12-bis[(2,4-dihydroxy-6-methylphenyl)amino]-3,13-dimethyl-8-oxatricyclo[7.4.0.02,7]trideca-1,3,6,9,12-pentaene-5,11-dione
4,12-bis[(2,4-dihydroxy-6-methylphenyl)amino]-3,13-dimethyl-8-oxatricyclo[7.4.0.0²,⁷]trideca-1,3,6,9,12-pentaene-5,11-dione
4,12-bis[(2,4-dihydroxy-6-methylphenyl)amino]-3,13-dimethyl-8-oxatricyclo[7.4.0.0²,â·]trideca-1,3,6,9,12-pentaene-5,11-dione
C.I. Natural Red 28