preferred_name: an S-substituted L-cysteine + glycine => an S-substituted L-cysteinylglycine + H2O
preferred_name_lc: an s-substituted l-cysteine + glycine => an s-substituted l-cysteinylglycine + h2o
label: an S-substituted L-cysteine + glycine => an S-substituted L-cysteinylglycine + H2O
label_lc: an s-substituted l-cysteine + glycine => an s-substituted l-cysteinylglycine + h2o