preferred_name: biotin(out) + 2 Na(+)(out) <=> biotin(in) + 2 Na(+)(in)
preferred_name_lc: biotin(out) + 2 na(+)(out) <=> biotin(in) + 2 na(+)(in)
label: biotin(out) + 2 Na(+)(out) <=> biotin(in) + 2 Na(+)(in)
label_lc: biotin(out) + 2 na(+)(out) <=> biotin(in) + 2 na(+)(in)