orellanine

2,2'-Bi[pyridine-3,4-diol]1,1'-dioxide

[2,2'-Bipyridine]-3,3',4,4'-tetrol,1,1'-dioxide

2-(3,4-Dihydroxy-1-oxidopyridin-1-ium-2-yl)-3,4-dihydroxypyridin-1-ium-1-olate