preferred_name: S-[(2R)-succino]-L-cysteine => fumarate + L-cysteine
preferred_name_lc: s-[(2r)-succino]-l-cysteine => fumarate + l-cysteine
label: S-[(2R)-succino]-L-cysteine => fumarate + L-cysteine
label_lc: s-[(2r)-succino]-l-cysteine => fumarate + l-cysteine