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