N-acetyl-D-phenylalanine => N-acetyl-L-phenylalanine
n-acetyl-d-phenylalanine => n-acetyl-l-phenylalanine
N-acetyl-D-phenylalanine => N-acetyl-L-phenylalanine
n-acetyl-d-phenylalanine => n-acetyl-l-phenylalanine