preferred_name: nitrate(in) + chloride(out) = nitrate(out) + chloride(in)
preferred_name_lc: nitrate(in) + chloride(out) = nitrate(out) + chloride(in)
label: nitrate(in) + chloride(out) = nitrate(out) + chloride(in)
label_lc: nitrate(in) + chloride(out) = nitrate(out) + chloride(in)