the formation of the d-amino acid-peptidoglycan linkage was insensitive to beta-lactam antibiotics such as benzylpenicillin and ampicillin ( 500 micrograms/ml ) and therefore was not due to the reaction of dd-transpeptidation which is involved in the biosynthesis of peptidoglycan .
C0030827
benzylpenicillin
C0002680
ampicillin