Indigo


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Idioms, Wikipedia.

indigo

[Span.; from Lat.,=Indian], important blue dyestuff used in printing inks and for vat dyeing of cotton (see dyedye,
any substance, natural or synthetic, used to color various materials, especially textiles, leather, and food. Natural dyes are so called because they are obtained from plants (e.g., alizarin, catechu, indigo, and logwood), from animals (e.g.
..... Click the link for more information.
). It was anciently produced in India and was known in Egypt, probably c.1600 B.C.; mummies of the XVIII dynasty have been discovered wrapped in indigo-dyed cloth. Indigo is obtained from leguminous plants of the genus Indigofera, chiefly from the Asian species Indigofera tinctoria, but also from several other species. The plants contain a colorless, soluble glucoside called indican. When the macerated plants are allowed to ferment in vats of water the colorless form of indigo is liberated; stirring of the liquid causes oxidation of the colorless material to form a blue sediment. The natural indigo gives a strong blue color of great permanence. Use of the natural dye greatly decreased after the synthesis of indigo was accomplished. Adolf von Baeyer was the first to synthesize it, but others developed the methods used for its commercial production from anilineaniline
, C6H5NH2, colorless, oily, basic liquid organic compound; chemically, a primary aromatic amine whose molecule is formed by replacing one hydrogen atom of a benzene molecule with an amino group.
..... Click the link for more information.
 and chloroacetic acid.

Indigo

 

plants containing the glycoside indican, the source of blue indigo dye. Only a few indigo plants contain a sufficient quantity of indican for practical use. The most important indigo plant is Indigofera tinctoria, which is native to southern Asia and was once widely cultivated. After the synthesis of indigo, the significance of this and other indigo plants decreased sharply. In the USSR the species Isatis tinctoria and Polygonum tinctoria are occasionally cultivated


Indigo

 

a dark blue crystalline substance; its structural formula is Its melting point is 390°-392°C (with decomposition). It is insoluble in water and alcohol and slightly soluble in other organic solvents.

Indigo, which has been known since remote antiquity, is a dye obtained from indigo plants (for example, Indigofera tinctoria); it is extensively used for vat dyeing cotton and silk blue. The principal method of obtaining indigo is by reacting aniline with chloroacetic acid to give phenylglycine, which is then fused with alkali to give indoxyl, which in turn is oxidized to indigo by the oxygen in the air. Reduction of indigo gives the leuco compound indigo white, whose sodium salt of sulfuric acid ester is called indigosol. Owing to the inadequate durability of indigo, it has been replaced by other vat dyes. The determination of the structure of indigo and development of methods of synthesizing it at the end of the 19th century was the start of the development of the manufacture of indigoid dyes.

IU. E. GERASIMENKO

indigo

[′in·də·gō]
(organic chemistry)
A blue dye extracted from species of the Indigofera bush.

indigo

1. any of various tropical plants of the leguminous genus Indigofera, such as the anil, that yield this dye
2. 
a. any of a group of colours that have the same blue-violet hue; a spectral colour
b. (as adjective): an indigo carpet

Indigo

(1) An earlier family of desktop graphics computers from SGI. The low end were the Indy machines, which included their own digital video camera. The high end included a variety of Indigo workstations, with models specialized for graphics functions such as accelerated texture mapping and image processing. See SGI.

(2) The code name of the messaging system introduced in Windows Vista. See Windows Communication Foundation.
References in periodicals archive ?
It is prized for being vibrant and long-lasting, and was an important cash crop until humans started making synthetic indigo in the early 1900s.
Indigo, founded by Flagship Pioneering, is headquartered in Boston, with commercial operations based in Memphis and international offices in Sydney, Australia, Buenos Aires, Argentina, and SAaAaAeAeAaAaAeA o Paulo, Bra
The Minister of Agriculture said that in 1907, Sheikh Gulab and Sital Rai had raised their voice against the indigo farming.
I inherited not only her habit of inviting friends to share summer indigo dyeing sessions, but also, later, her special indigo dye vat, in whose mysterious depths my journey had begun.
HP Indigo digital presses for label production are equipped with a color management system, variable data printing module, security module and seven colors for process and spot printing.
Archroma's Denisol Indigo 30 is a newly developed pre-reduced solution that does not use sodium hydroxide and sodium hydrosulfite to make a stock vat.
According to HP, with the B2-format HP Indigo 10000 Digital Presses and HP Indigo 7800 Digital Presses, Quantum Group can offer its wide range of integrated solutions, including sheetfed print, bindery and finishing, inventory and fulfillment as well as proprietary online print management programs, with a higher level of client service and faster delivery than previously possible.
When CISF officials asked IndiGo official that why they left him alone, they said few officials went for evening snacks while others went to check other passengers.
The new 60 room Hotel Indigo Birmingham-Waterloo Street will be located in the Colmore Business District of Birmingham.
modernisation have posed dual threats to the existence of Omana€™s indigo industries, and the number of artisans engaged in the craft has declined almost to the point of extinction.
To give denim this worn-in appearance, manufacturers wash the denim with rough stones, which scrapes off layers of indigo.