A long-lived o-semiquinone radical anion is formed from N-β-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine(5-S-GAD),an insect-derived antibacterial substance.

We found that an o-semiquinone radical anion was formed from 5-S-GAD. This radical formation is involved in the production of hydrogen peroxide from 5-S-GAD.

J.Biochem.142(1)