Abstract
Superoxide production by the three 4,9-dihydroxyperylene-3,10-quinone fungal toxins, altertoxins I, II, and III, was stimulated on illumination with broad-spectrum light. As determined previously for cercosporin, superoxide production by illuminated altertoxins was increased by the addition of the reducing substances ergothioneine or urate; ascorbate also effectively increased superoxide production. Illuminated urate alone engendered some superoxide production.