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