Alizarin
IUPAC name 1,2-dihydroxy-9,10-anthracenedione
Other names 1,2-Dihydroxyanthraquinone, Turkey red, Mordant red 11, Alizarin B, Alizarin red
Identifiers
CAS number	72-48-0 Y
PubChem	6293
ChemSpider	6056 Y
UNII	60MEW57T9G Y
KEGG	C01474 Y
ChEBI	CHEBI:16866 Y
ChEMBL	CHEMBL55814 Y
Jmol-3D images	Image 1
SMILES O=C2c1ccccc1C(=O)c3c2ccc(O)c3O
InChI InChI=1S/C14H8O4/c15-10-6-5-9-11(14(10)18)13(17)8-4-2-1-3-7(8)12(9)16/h1-6,15,18H Y Key: RGCKGOZRHPZPFP-UHFFFAOYSA-N Y InChI=1/C14H8O4/c15-10-6-5-9-11(14(10)18)13(17)8-4-2-1-3-7(8)12(9)16/h1-6,15,18H Key: RGCKGOZRHPZPFP-UHFFFAOYAG
Properties
Molecular formula	C14H8O4
Molar mass	240.21 g mol−1
Appearance	orange-red crystals or powder
Density	1.540 g/cm3
Melting point	279–83 °C
Boiling point	430 °C
Solubility in water	slightly to sparingly soluble
Acidity (pKa)	6.94
Hazards
MSDS	External MSDS
R-phrases	R36 R37 R38
S-phrases	S26 S36
Related compounds
Related compounds	anthraquinone, anthracene
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Alizarin or 1,2-dihydroxyanthraquinone (also known as Mordant Red 11 and Turkey Red^[1]) is an organic compound with formula C₁₄H₈O₄ that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus.^[2] In 1869, it became the first natural pigment to be duplicated synthetically.^[3]

Alizarin is the main ingredient for the manufacture of the madder lake pigments known to painters as Rose madder and Alizarin crimson. Alizarin in the commonest usage of the term has a deep red color, but the term is also part of the name for several related non-red dyes, such as Alizarine Cyanine Green and Alizarine Brilliant Blue. A notable use of alizarin in modern times is as a staining agent in biological research because it stains free calcium and certain calcium compounds a red or light purple color. Alizarin continues to be used commercially as a red textile dye, but to a lesser extent than 100 years ago.

History[link]

Madder has been cultivated as a dyestuff since antiquity in central Asia and Egypt, where it was grown as early as 1500 BC. Cloth dyed with madder root pigment was found in the tomb of the Pharaoh Tutankhamun and in the ruins of Pompeii and ancient Corinth.^{[citation needed]} In the Middle Ages, Charlemagne encouraged madder cultivation. Madder was widely used as a dye in Western Europe in the Late Medieval centuries.^[4] In 17th century England, alizarin was used as a red dye for the clothing of the parliamentary New Model Army. The distinctive red color would continue to be worn for centuries (though also produced by other dyes such as cochineal), giving English and later British soldiers the nickname of "redcoats".

alizarin color

The madder dyestuff is combined with a dye mordant. According to which mordant used, the resulting color may be anywhere from pink through purple to dark brown. In the 18th century the most valued color was a bright red known as "Turkey Red". The combination of mordants and overall technique used to obtain the Turkey Red originated in the Middle East or Turkey (hence the name). It was a complex and multi-step technique in its Middle Eastern formulation, some parts of which were unnecessary.^[5] The process was simplified in late 18th century Europe. By 1804, a dye maker George Field in Britain had refined a technique to make lake madder by treating it with alum, and an alkali,^[6] that converts the water-soluble madder extract into a solid, insoluble pigment. This resulting madder lake has a longer-lasting color, and can be used more efficaciously, for example by blending it into a paint. Over the following years, it was found that other metal salts, including those containing iron, tin, and chromium, could be used in place of alum to give madder-based pigments of various other colors. This general method of preparing lakes has been known for centuries^[7] but was simplified in the late 18th and early 19th centuries.

In 1826, the French chemist Pierre-Jean Robiquet found that madder root contained two colorants, the red alizarin and the more rapidly fading purpurin. The alizarin component became the first natural dye to be synthetically duplicated in 1868 when the German chemists Carl Graebe and Carl Liebermann, working for BASF, found a way to produce it from anthracene. About the same time, the English dye chemist William Henry Perkin independently discovered the same synthesis, although the BASF group filed their patent before Perkin by only one day. The subsequent discovery (made by Broenner and Gutzhow in 1871) that anthracene could be abstracted from coal tar further advanced the importance and affordability of alizarin's artificial synthesis.^[8]

The synthetic alizarin could be produced for a fraction of the cost of the natural product, and the market for madder collapsed virtually overnight. The principal synthesis entailed oxidation of anthraquinone-2-sulfonic acid with sodium nitrate in concentrated sodium hydroxide. Alizarin itself has been in turn largely replaced today by the more light-resistant quinacridone pigments developed at DuPont in 1958.

Structure and properties[link]

Alizarin is one of ten dihydroxyanthraquinone isomers. Its molecular structure can be viewed as being derived from anthraquinone by replacement of two neighboring hydrogen atoms (H) by hydroxyl groups (-OH).

It is soluble in hexane and chloroform, and can be obtained from the latter as red-purple crystals, m.p. 277–278 °C.^[2]

Alizarin changes color depending on the pH of the solution it is in, thereby making it a pH indicator.^[9]

Applications[link]

Alizarin Red is used in a biochemical assay to determine, quantitatively by colorimetry, the presence of calcific deposition by cells of an osteogenic lineage. As such it is an early stage marker (days 10–16 of in vitro culture) of matrix mineralization, a crucial step towards the formation of calcified extracellular matrix associated with true bone.^{[citation needed]}

Alizarin's abilities as a biological stain were first noted in 1567, when it was observed that when fed to animals, it stained their teeth and bones red. The chemical is now commonly used in medical studies involving calcium. Free (ionic) calcium forms precipitates with alizarin, and tissue block containing calcium stain red immediately when immersed in alizarin. Thus, both pure calcium and calcium in bones and other tissues can be stained. The process of staining calcium with alizarin works best when conducted in basic solution.^[10]

In clinical practice, it is used to stain synovial fluid to assess for basic calcium phosphate crystals.^[11] Alizarin has also been used in studies involving bone growth, osteoporosis, bone marrow, calcium deposits in the vascular system, cellular signaling, gene expression, tissue engineering, and mesenchymal stem cells.^[12]

In geology, it is used as a stain to indicate the calcium carbonate minerals, calcite and aragonite.^[13]

See also[link]

• Alizarine ink
• Aniline
• 1,2,4-Trihydroxyanthraquinone or purpurin, another red dye that occurs in madder root.
• Hydroxyanthraquinone
• Dihydroxyanthraquinone
• List of dyes
• List of colors (compact)

References[link]

External links[link]

• Molecule of the day: Alizarin

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Bill Pere, a multiple-award-winning singer, songwriter, producer, musician, author, and playwright, was named one of the "Top 50 Innovators, Groundbreakers, Iconoclasts, and Guiding Lights of the Music Industry" by Music Connection Magazine in December 2008. His accomplishments include being named Connecticut State Troubadour in 1995 and an Independent Music Conference - "Immie" Award winner for Best Independent Artist in 2003. Pere has written more than 400 songs and released 16 CDs, as well as producing CDs for many other artists.

Pere is a Founding Member and current President of the Connecticut Songwriters' Association and is Founder and Executive Director of the Local United Network to Combat Hunger (LUNCH), which features the LUNCH Ensemble. Along with Kay Pere, also a nationally-known recording artist, he runs the Connecticut Songwriting Academy to develop the talents and careers of young singers, songwriters, musicians, and recording artists. Pere has been involved in the music business for more than 30 years, having been mentored by many of the top names in the industry. He uses music for social activism, fighting hunger and poverty, and was named a "Hunger Fighting Hero" by Wakefern Foods in 2009, and was featured on a special edition Cheerios box.

In 2009 Pere released his book "Songcrafters' Coloring Book: The Essential Guide to Effective and Successful Songwriting", which presents 30 years of research and insights into the nature of songwriting. This is an outgrowth of a series of articles by Pere on songwriting and the music industry, published in the 1980s and 1990s, known as The Songcrafters' Coloring Book. Pere presents workshops and classes at music conferences and events across the U.S.

Biography[link]

Bill Pere grew up in New York City and today resides in Connecticut. He is a graduate of Bucknell University in Lewisburg, Pennsylvania.

Recordings[link]

1981: Crest of a Wave [vinyl]
198?: Cityscape [vinyl]
198?: Family Portrait [out of print]
1991: Songs for Kids Who Like to Think
1994: You'll See a Much Brighter Day
1994: Songs for Kids With Common Sense
1994: Profiles of Connecticut Vol 1
1995: Songs for Kids Who Touch the Stars
1999: New Day Coming Tomorrow
2001: Crest of a Wave (10th Anniversary - New Recordings)
2001: Cityscape II
2002: High School My School
2002: Christmas Eve on the Poor Side of Town
2004: Profiles of Connecticut Special Edition
2007: Dare to Dream
2010: Voices For Hope

2010: plus numerous inclusions on compilation CDs

See also[link]

• Bartholomew Cubbins

Links[link]

• Bill Pere Official Website
• Local United Network to Combat Hunger
• Connecticut Songwriters' Association
• Connecticut Songwriting Academy