2,3-dihydroxybenzoate + O2 <=> 2-hydroxy-3-(3-oxoprop-1-enyl)but-2-enedioate + H(+)
2,3-dihydroxybenzoate + o2 <=> 2-hydroxy-3-(3-oxoprop-1-enyl)but-2-enedioate + h(+)
2,3-dihydroxybenzoate + O2 <=> 2-hydroxy-3-(3-oxoprop-1-enyl)but-2-enedioate + H(+)
2,3-dihydroxybenzoate + o2 <=> 2-hydroxy-3-(3-oxoprop-1-enyl)but-2-enedioate + h(+)