preferred_name: N-acetyl-L-phenylalanine => N-acetyl-D-phenylalanine
preferred_name_lc: n-acetyl-l-phenylalanine => n-acetyl-d-phenylalanine
label: N-acetyl-L-phenylalanine => N-acetyl-D-phenylalanine
label_lc: n-acetyl-l-phenylalanine => n-acetyl-d-phenylalanine