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