Isoalloxazine

Isoalloxazine
Names
	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
CAS Number	490-59-5;
3D model (JSmol)	Interactive image;
Beilstein Reference	85819
ChEBI	CHEBI:37325;
ChEMBL	ChEMBL68500;
ChemSpider	4522915;
ECHA InfoCard	100.007.014
EC Number	207-714-3;
IUPHAR/BPS	456;
PubChem CID	5372720;
UNII	880W3VF9YW;
CompTox Dashboard (EPA)	DTXSID50197656 ;
	InChI InChI=1S/C10H6N4O2/c15-9-7-8(13-10(16)14-9)12-6-4-2-1-3-5(6)11-7/h1-4H,(H2,12,13,14,15,16) Key: HAUGRYOERYOXHX-UHFFFAOYSA-N;
	SMILES C1=CC=C2C(=C1)N=C3C(=N2)NC(=O)NC3=O;
Properties
Chemical formula	C10H6N4O2
Molar mass	214.184 g·mol−1
Appearance	Red solid
Melting point	200 °C (392 °F; 473 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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.

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]

References

^ ^a ^b ^c ^d ^e 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.

[Berezovskii1963-1] 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.

[2] "isoalloxazine". Farlex Partner Medical Dictionary. 2012. Retrieved November 25, 2022.

[3] 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.

[4] 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.

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