preferred_name: 2 L-cysteine => L-lanthionine + hydrogen sulfide + H(+)
preferred_name_lc: 2 l-cysteine => l-lanthionine + hydrogen sulfide + h(+)
label: 2 L-cysteine => L-lanthionine + hydrogen sulfide + H(+)
label_lc: 2 l-cysteine => l-lanthionine + hydrogen sulfide + h(+)