PROFILBARU.COM

A dihydroxyanthraquinone is any of several isomeric organic compounds with formula (C₁₂H₆(OH)₂)(CO)₂, formally derived from 9,10-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 (histazarin)
2,6-Dihydroxyanthraquinone (anthraflavic acid)
2,7-Dihydroxyanthraquinone (isoanthraflavic acid)

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]

References

^ ^a ^b Wahl, Andre; Atack, F. W. (1919). The Manufacture Of Organic Dyestuffs. London: G. Bell And Sons, Limited. pp. 202–212.
^ McGuigan, Hugh Alister (1921). An introduction to chemical pharmacology; pharmacodynamics in relation to chemistry. Philadelphia: P. Blakiston's son & Co. p. 132.
^ Khalafy, Jabbar; Bruce, J.M. (2002-06-01). "Oxidative dehydrogenation of 1-tetralones: Synthesis of juglone, naphthazarin, and α-hydroxyanthraquinones". Journal of Sciences, Islamic Republic of Iran. 13 (2). ISSN 1016-1104. 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.
^ Thomson, Ronald Hunter (1971). Naturally Occurring Quinones. Academic Press. p. 66. ISBN 978-0-12-689650-3.
^ Thomson, Ronald Hunter (1987). Naturally Occurring Quinones III: Recent Advances. Springer Netherlands. p. 358. ISBN 978-0-412-26730-7.
^ Arcamone, Federico (1981). Doxorubicin: Anticancer Antibiotics. Academic Press. ISBN 978-0-12-059280-7.
^ Ross Kelly, T. (1984). "Preface". Tetrahedron. 40 (22): 4537. doi:10.1016/S0040-4020(01)91512-1.
^ Ashton, Richard E.; Andre, Pierre; Lowe, Nicholas J.; Whitefield, Martin (1983). "Anthralin: Historical and current perspectives". Journal of the American Academy of Dermatology. 9 (2): 173–192. doi:10.1016/s0190-9622(83)70125-8. PMID 6309924.
^ Kemény, L.; Ruzicka, T.; Braun-Falco, O. (1990). "Dithranol: a review of the mechanism of action in the treatment of psoriasis vulgaris". Skin Pharmacology. 3 (1): 1–20. ISSN 1011-0283. PMID 2202336.
^ ^a ^b Buckingham, John B. (1996). Dictionary of Organic Compounds. Vol. 1. Chapman & Hall. ISBN 978-0-412-54090-5.