preferred_name: fumarate(in) + citrate(out) <=> fumarate(out) + citrate(in)
preferred_name_lc: fumarate(in) + citrate(out) <=> fumarate(out) + citrate(in)
label: fumarate(in) + citrate(out) <=> fumarate(out) + citrate(in)
label_lc: fumarate(in) + citrate(out) <=> fumarate(out) + citrate(in)