Dihydroxyanthraquinone

A dihydroxyanthraquinone is any of several isomeric organic compounds with formula C₁₄H₈O₄, formally derived from an anthraquinone by replacing two hydrogen atoms by hydroxyl groups. Dihyroxyantraquinones have been studied since the early 1900s, and include some compounds of historical and current importance.^[1][2] The isomers differ in the position of the hydroxyl groups, and of the carbonyl oxygens (=O) of the underlying anthraquinone.

Isomers

From 9,10-anthraquinone

The unqualified term "dihydroxyanthraquinone" usually means a hydroxy derivative of 9,10-anthraquinone. The dihydroxy-9,10-anthraquinone functional group occurs widely in natural products,^{[3][4] [5]}and is an important feature of the anthracycline antitumour antibiotics.^[6][7] In particular, 1,8-Dihydroxy-9,10-anthraquinone is the precursor for the important topical antipsoriatic drug anthralin, 1,8-dihydroxy-9-anthrone,^[8][9]

There are 28 ways of choosing two of the 8 possible hydrogens, but because of the four-fold symmetry of the 9,10-anthraquinone core there are only 10 distinct isomers.^[10]

• 1,2-Dihydroxyanthraquinone (alizarin)
• 1,3-Dihydroxyanthraquinone (purpuroxanthin, xantopurpurin)
• 1,4-Dihydroxyanthraquinone (quinizarin)
• 1,5-Dihydroxyanthraquinone (anthrarufin)
• 1,6-Dihydroxyanthraquinone
• 1,7-Dihydroxyanthraquinone
• 1,8-Dihydroxyanthraquinone (dantron, chrysazin)
• 2,3-Dihydroxyanthraquinone
• 2,6-Dihydroxyanthraquinone
• 2,7-Dihydroxyanthraquinone

From other anthraquinones

There are also many dihydroxy derivatives of other anthraquinones, such as 1,2-anthraquinone, 1,4-anthraquinone, and 2,6-anthraquinone.^[10]

See also

• Hydroxyquinone
• Hydroxybenzoquinone
• Hydroxynaphthoquinone
• Hydroxyanthraquinone
• Trihydroxyanthraquinone
• Tetrahydroxyanthraquinone
• Pentahydroxyanthraquinone
• Hexahydroxyanthraquinone
• Heptahydroxyanthraquinone
• Octahydroxyanthraquinone^[1]

References

1. ^ ^{a b} Wahl, Andre; Atack, F. W (1919) The Manufacture Of Organic Dyestuffs. G. Bell And Sons, Limited. Online version accessed on 2010-01-22.
2. ^ Hugh Alister McGuigan (1921), An introduction to chemical pharmacology; pharmacodynamics in relation to chemistry. P. Blakiston's son, Philadelphia. Online version at archive.org, accessed on 2010-01-30.
3. ^ J. Khalafy and J.M. Bruce (2002), Oxidative dehydrogenation of 1-tetralones: Synthesis of juglone, naphthazarin, and [alpha]-hydroxyanthraquinones. Journal of Sciences, Islamic Republic of Iran, volume 13 issue 2, pages 131-139. "Silver(I) oxide in 1,4-dioxane converted 9,10-dihydroxy-1-oxo, 9,10-dihydroxy-1,5-dioxo, and 1,8-dioxo-1,2,3,4,5,6,7,8-octahydro anthracene into, respectively, 1-hydroxy-5,6,7,8-tetrahydro-, 1,5-dihydroxy-, and 1,8-dihydroxy-9,10-anthraquinone, in high yield."
4. ^ Thomson R.H. Naturally Occurring Quinones. Academic Press, London (1971). Quoted by Khalafy and Bruce.
5. ^ Thomson R.H. Naturally Occurring Quinones III. Chapman and Hall, London (1987). Quoted by Khalafy and Bruce.
6. ^ Arcamone F. (1981). Doxorubicin Anticancer Antibiotics. Academic Press, New York. Quoted by Khalafy and Bruce.
7. ^ Kelly T.R. (1984). Tetrahedron, 40: 22. Quoted by Khalafy and Bruce.
8. ^ Ashton R.E., Andre P., Lowe N.J. and Whitefield M. J. (1983). Am. Acad. Dermatol., 9: 173. Quoted by Khalafy and Bruce.
9. ^ Kemeny L., Ruzicka T. and Braun-Falco O. (1990). Skin Pharmacol., 3: 1. Quoted by Khalafy and Bruce.
10. ^ ^{a b} CRC (1996), Dictionary of organic compounds, Volume 1 CRC Press Online version at books.google.com, accessed on 2010-01-22.