preferred_name: thymine(in) + Na(+)(in) => thymine(out) + Na(+)(out)
preferred_name_lc: thymine(in) + na(+)(in) => thymine(out) + na(+)(out)
label: thymine(in) + Na(+)(in) => thymine(out) + Na(+)(out)
label_lc: thymine(in) + na(+)(in) => thymine(out) + na(+)(out)