Isoalloxazine
Isoalloxazine is the structural foundation of flavins such as riboflavin (vitamin B2) and is a heterocyclic compound.[2] It has a tricyclic structure which means it has three interconnected rings of atoms and is a tautomer of alloxazine.[1] The structure is formed by primary-secondary aromatic o-diamines and they are a high-melting crystalline substance.[1] The R-group is used to attach various flavin groups It has a similar structure to pteridines which has two interconnected rings.[1] Isoalloxazine was first obtained in 1934[1] by Richard Kuhn an Austrian-German biochemist and lab mates.
![](../I/Isoalloxazine_Structure.png.webp)
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Names | |
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IUPAC name
1H-benzo[g]pteridine-2,4-dione | |
Other names
1,2,3,4-Tetrahydrobenzopteridine-2,4-dione; Benzo(g)pteridine-2,4(1H,3H)-dione | |
Identifiers | |
3D model (JSmol) |
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85819 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.007.014 |
EC Number |
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PubChem CID |
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UNII | |
CompTox Dashboard (EPA) |
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Properties | |
C10H6N4O2 | |
Molar mass | 214.184 g·mol−1 |
Appearance | Red solid |
Melting point | 200 °C (392 °F; 473 K)[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
Isoalloxazine ring
Isoalloxazine rings can exist in different redox and ionization states depending on the chemistry of FMN and FAD associated with it.[3] Using the redox-active isoalloxazine system, FAD and FMN are able to do one and two electron transfer reactions and also be coupled with proton transfers [4]
![](../I/Ionization_and_redox_of_isoalloxazine_ring.png.webp)
References
- Berezovskii, VM; Eremenko, TV (1963). "Chemistry of Alloxazines and Isoalloxazines". Russian Chemical Reviews. 32 (6): 290–307. doi:10.1070/RC1963v032n06ABEH001343. Retrieved November 23, 2022.
- "isoalloxazine". Farlex Partner Medical Dictionary. 2012. Retrieved November 25, 2022.
- Luliano, James N. (2019). "Vibrational spectroscopy of flavoproteins". New Approaches for Flavin Catalysis. Methods in Enzymology. Vol. 620 (volume 620 ed.). Methods in Enzymology: Elsevier Inc. pp. 189–214. doi:10.1016/bs.mie.2019.03.011. ISBN 9780128168295. ISSN 0076-6879. PMID 31072487. S2CID 146800749.
- Aleksandrov, Alexey (2019). "A Molecular Mechanics Model for Flavins". Journal of Computational Chemistry. 40 (32): 2834–2842. doi:10.1002/jcc.26061. PMID 31471978. S2CID 201730443.