Hydroxynaphthoquinone

A hydroxynaphthoquinone (formula: {{chem|C|10|H|6|O|3}}) is any of several organic compounds that can be viewed as derivatives of a naphthoquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH).

In general, the term may mean any naphthoquinone derivative where any number n of hydrogens have been replaced by n hydroxyls, so that the formula is {{chem|C|10|H|6|O|2+n}}. In this case the number n (which is between 1 and 6) is indicated by a multiplier prefix (mono-, di-, tri-, tetra-, penta-, or hexa-).

The unqualified term "hydroxynaphthoquinone" usually means a derivative of 1,4-naphthoquinone. Other hydroxy- compounds can be derived from other isomers of the latter, such as 1,2-naphthoquinone and 2,6-naphthoquinone. The IUPAC nomenclature uses dihydronaphthalenedione instead of "naphthoquinone", with the necessary prefixes to indicate the positions of the carbonyl oxygens (=O) — as in 5,8-dihydroxy-1a,8a-dihydronaphthalene-1,4-dione (= 5,8-dihydroxy-1,4-naphthoquinone).

The hydroxynaphtoquinones (in the particular or the general sense) include many biologically and industrially important compounds, and are a building-block of many medicinal drugs.{{ cite journal |author1=Khalafy, J. |author2=Bruce, J. M. | year = 2002 | title = Oxidative Dehydrogenation of 1-Tetralones: Synthesis of Juglone, Naphthazarin, and α-Hydroxyanthraquinones | journal = Journal of Sciences, Islamic Republic of Iran | volume = 13 | issue = 2 | pages = 131–139 | url = http://www.sid.ir/en/VEWSSID/J_pdf/97320020202.pdf | format = pdf }}{{ cite book | author = Thomson, R. H. | title = Naturally Occurring Quinones | url = https://archive.org/details/naturallyoccurri0000thom | url-access = registration | publisher = Academic Press | location = London | year = 1971 }} Quoted by Khalafy and Bruce.{{ cite book | author = Thomson, R. H. | title = Naturally Occurring Quinones III | publisher = Chapman and Hall | location = London | year = 1987 }} Quoted by Khalafy and Bruce.

(Mono)hydroxynaphtoquinones

=From 1,4-naphthoquinone=

Due to its symmetry there are only three isomers:

2-Hydroxy-1,4-naphthoquinone (lawsone), coloring principle of henna.
5-Hydroxy-1,4-naphthoquinone (juglone), coloring principle of black walnut.{{ cite journal |author1=Taylor, R. T. |author2=Flood, L. A. | title = Polystyrene-Bound Phenylseleninic Acid: Catalytic Oxidations of Olefins, Ketones, and Aromatic Systems | journal = The Journal of Organic Chemistry | year = 1983 | volume = 48 | issue = 26 | pages = 5160–5164 | doi = 10.1021/jo00174a003 }} Also active antimicrobial principle in Caesalpinia sappan heartwood.{{ cite journal |author1=Lim, M.-Y. |author2=Jeon, J.-H. |author3=Jeong, E. Y. |author4=Lee, C. H. |author5=Lee, H.-S. | title = Antimicrobial Activity of 5-Hydroxy-1,4-Naphthoquinone Isolated from Caesalpinia sappan toward Intestinal Bacteria | journal = Food Chemistry | year = 2007 | volume = 100 | issue = 3 | pages = 1254–1258 | doi = 10.1016/j.foodchem.2005.12.009 }}
6-Hydroxy-1,4-naphthoquinone, can be prepared from 1,7-dihydroxynaphthalene.{{ cite journal |author1=Teuber, H.-J. |author2=Götz, N. | title = Reaktionen mit Nitrosodisulfonat, V. Mitteilung: Über die Bildung von Naphtochinonen | journal = Chemische Berichte | year = 1954 | volume = 87 | issue = 9 | pages = 1236–1251 | doi = 10.1002/cber.19540870908 }}

One of the main products of photochemical oxidation of 1-naphthol.{{ cite journal |author1=Brahmia, O. |author2=Richard, C. | title = Photochemical Transformation of 1-Naphthol in Aerated Aqueous Solution | journal = Photochemical & Photobiological Sciences | year = 2005 | volume = 4 | issue = 6 | pages = 454–458 | doi = 10.1039/B504309C | pmid = 15920628 | doi-access = free }}

=From 1,2-naphthoquinone=

From 1,2-naphthoquinone (ortho-naphthoquinone) there are 6 possible isomers:

3-Hydroxy-1,2-naphthoquinone
4-Hydroxy-1,2-naphthoquinone{{ cite journal |author1=Garge, P. |author2=Padhye, S. |author3=Tuchagues, J.-P. | title = Iron(II) Complexes of ortho-Functionalized para-Naphthoquinones 1. Synthesis, Characterization, Electronic Structure and Magnetic Properties | journal = Inorganica Chimica Acta | year = 1989 | volume = 157 | issue = 2 | pages = 239–249 | doi = 10.1016/S0020-1693(00)80548-4 }}

{{ cite journal |author1=Rane, S. Y. |author2=Ahmed, K. |author3=Salunke-Gawali, S. | title = Temperature Effect on Ancillary μ-Carbonato Ligand Modes in Hydroxy Naphthoquinonato Copper(II) Complex: An EPR Spectroscopic and Magnetic Coupling Evidences | journal = Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry | year = 2006 | volume = 36 | issue = 5 | pages = 391–398 | doi = 10.1080/15533170600729037 }}

=From 2,3-naphthoquinone=

From 2,3-naphthoquinone, also a symmetric molecule there are only three isomers:

=From 2,6-naphthoquinone=

From the symmetrical 2,6-naphthoquinone (amphi-naphthoquinone) there are only three:

(Poly)hydroxynaphthoquinones

References

Category:Hydroxynaphthoquinones