Flavonoids that may interact with bortezomib. (A) The structures of bortezomib and epigallocatechin galate are shown, as is the reaction by which a boronic acid and a 1,2-diol group can form a cyclic boronate. (B) The structures of epigallocatechin galate, epigallocatechin, epicatechin, theaflavin, quercetin, myricetin, catechol, epinephrine, norepinephrine, dopamine, resorcinol, and chrysoine resorcinol are shown.