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