What is Isoalloxazine ring?

Isoalloxazine ring of FAD is required for the formation of the core in the Hsp60-assisted folding of medium chain acyl-CoA dehydrogenase subunit into the assembly competent conformation in mitochondria.

Where is flavin found?

For humans, flavins are obtained as vitamin B2 in the diet. Flavins are found in cells as either flavin mononucleotide or flavin adenine dinucleotide, and are almost entirely bound into the structure of proteins.

What is flavin reduction?

Flavin (from Latin flavus, “yellow”) is the common name for a group of organic compounds based on pteridine, formed by the tricyclic heterocycle isoalloxazine. The flavin group is capable of undergoing oxidation-reduction reactions, and can accept either one electron in a two-step process or two electrons at once.

Which is associated with the isoalloxazine ring?

The chemistry of FMN and FAD is associated with the isoalloxazine ring which can exist in several different ionization/redox states (Fig. 3 ).

What is the interaction between adenine and isoalloxazine?

That strong interaction exists between the adenine and isoalloxazine rings of FAD is evident from the self-quenching of fluorescence compared to that of riboflavin or FMN.3612 Proton NMR data indicate that the rings are hydrogen bonded to each other.

How does riboflavin form an isoalloxazine intermediate?

Flavins, derived from riboflavin (vitamin B 5) possess a characteristic tricyclic isoalloxazine structure which, when reduced to FADH2 23, usually by NAD (P)H, can react with molecular oxygen to form a (hydro)peroxy flavin intermediate suitable for the oxidation of organic substrates. These reactions are summarized in Scheme 8.2. Figure 8.9.

How is the synthesis of isoalloxazine 10 done?

The isoalloxazines 10 can be synthesized by heating the quinoxaline ( 13) with guanidine ( 14) under nitrogen atmosphere and in the dark in the presence of methyl, ethyl, or n -propyl alcohol and sodium alcoholate to the refluxing temperature for 1–90 h ( Scheme 14.3) [16,18]. Scheme 14.3. Synthesis of isoalloxazine from quinoxaline.