a D-alpha-amino acid + a carboxylate => an N-acyl-D-amino acid + H2O
a d-alpha-amino acid + a carboxylate => an n-acyl-d-amino acid + h2o
a D-alpha-amino acid + a carboxylate => an N-acyl-D-amino acid + H2O
a d-alpha-amino acid + a carboxylate => an n-acyl-d-amino acid + h2o