alizarin
1,2-Dihydroxyanthraquinone; a red dye that occurs in the root of madder (Rubia tinctorum and other Rubiaceae) in glucose combination (ruberythric acid) as orange needles, slightly soluble in water; used by the ancients as a dye. Now made synthetically from anthracene and used in the manufacture of dyes, e.g., a. blue, a. orange, “Turkey red.” As an indicator, it is yellow below pH 5.5 and red above pH 6.8; other modified alizarins have other colors and change color at other pH values.
- a. cyanin [C.I. 58610] disulfonate of hexahydroxyanthraquinone; an acid dye used as a nuclear stain after mordanting and as a fluorochrome in ultraviolet microscopy.
- a. purpurin SYN: purpurin (2).
- a. red S [C.I. 58005] sodium a. sulfonate; used as a stain for calcium in bone (calcium appears red-orange, magnesium, aluminum, and barium are varying shades of red), in the determination of fluorine; as a pH indicator it changes from yellow to purple between pH 3.7 and 5.2.

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aliz·a·rin ə-'liz-ə-rən also aliz·a·rine -rən, -.rēn n
1) an orange or red crystalline compound C14H8O4 formerly prepared from madder and now made synthetically from anthraquinone that was formerly used in dyeing but is now used more in making red pigments
2) any of a group of dyes that are similar to alizarin in dyeing properties or derivation

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n.
an orange-red dye derived from coal tar and originally isolated from the plant madder (Rubia tinctorum). Alizarin is insoluble in water but dissolves in alkalis, alcohol, and ether. It is used as a pH indicator and as a histochemical reagent for calcium, thallium, titanium, and zirconium.

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aliz·a·rin (ə-lizґə-rin) [Ar. ala sara extract] a red crystalline dye, prepared synthetically or obtained from madder; its compounds are used as indicators.

Medical dictionary. 2011.

Look at other dictionaries:

  • alizarin — carmine; n. an orange red dye derived from coal tar and originally isolated from the plant madder (Rubia tinctorum). Alizarin is insoluble in water but dissolves in alkalis, alcohol, and ether. It is used as a pH indicator and as a histochemical… …   The new mediacal dictionary

  • Alizarin — A*liz a*rin, Alizarine A*liz a*rine, n. [F. alizarine, fr. alizari.] (Chem.) A coloring principle, {C14H6O2(OH)2}, found in madder, and now produced artificially as an an orange red crystalline compound from anthracene. It is used in making red… …   The Collaborative International Dictionary of English

  • Alizărin — (Alizzari, Krapproth, Lizarinsäure), C20H6O6 + 4aq., Farbestoff der Krappwurzel, von Robiquet u. Colin entdeckte, dem Musivgold ähnliche gelbe Blättchen, od. rothe, durchsichtige, seidenglänzende Nadeln bildend, wenig in Wasser, leicht in Alkohol …   Pierer's Universal-Lexikon

  • Alizarīn — (von Alizari, einer Sorte Krapp, Krapprot) C14H8O4 oder C6H4.CO.CO.C6H2(OH)2, Farbstoff, findet sich im Krapp als Zersetzungsprodukt der in der frischen Wurzel enthaltenen Ruberythrinsäure, die durch Fermente in A. und Zucker gespalten wird. A.… …   Meyers Großes Konversations-Lexikon

  • Alizarin — Alizarīn, Krapprot, der Farbstoff der Krappwurzel, Dioxyanthrachinon, durchsichtige, orangerote, prismatische Kristalle, in kaltem Wasser fast unlöslich, leicht löslich in Alkohol und Äther, mit Alkalien schöne violette, mit alkalischen Erden und …   Kleines Konversations-Lexikon

  • alizarin — [ə liz′ərin, ə liz′ərēnə liz′ə rin] n. [Ger < Fr & Sp alizari, dried madder root < Ar al ʿ uṣāra, the juice < ʿ aṣara, to press] a reddish yellow crystalline compound, C6H4 (CO) 2C6H2 (OH) 2, produced by oxidizing anthracene and used in… …   English World dictionary

  • Alizarin — Madder lake redirects here. For the Australian band, see Madder Lake (band). Alizarin …   Wikipedia

  • Alizarin — Strukturformel Allgemeines Name Alizarin Andere Namen …   Deutsch Wikipedia

  • alizarin — /euh liz euhr in/, n. Chem. a solid appearing reddish orange as crystals and brownish yellow as powder, C14H8O4, one of the earliest known dyes, formerly obtained in its natural state from madder and now derived from anthraquinone: used chiefly… …   Universalium

  • Alizarin — Ali|za|rin 〈n. 11; unz.〉 in der Krappwurzel als Ruberythrinsäure vorkommender Naturfarbstoff, der auch synthetisch hergestellt werden kann u. durch Schmelzen von anthrachinosulfosaurem Natrium mit Natriumhydroxyd u. Kaliumchlorat gewonnen wird… …   Universal-Lexikon

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