preferred_name: an N-acyl-D-glucosamine => an N-acyl-D-mannosamine
preferred_name_lc: an n-acyl-d-glucosamine => an n-acyl-d-mannosamine
label: an N-acyl-D-glucosamine => an N-acyl-D-mannosamine
label_lc: an n-acyl-d-glucosamine => an n-acyl-d-mannosamine