(Z)-3,3'-dihydroxy-4H,4'H-[1,1'-binaphthalenylidene]-4,4'-dione

glycyl-p-benzoquinone

N-(3,6-dioxo-cyclohexa-1,4-dienyl)-alanine

(S)-2-((3,6-dioxocyclohexa-1,4-dien-1-yl)amino)-3-methylbutanoic acid