preferred_name: choline(out) + 2 H(+)(in) => choline(in) + 2 H(+)(out)
preferred_name_lc: choline(out) + 2 h(+)(in) => choline(in) + 2 h(+)(out)
label: choline(out) + 2 H(+)(in) => choline(in) + 2 H(+)(out)
label_lc: choline(out) + 2 h(+)(in) => choline(in) + 2 h(+)(out)