Chemical aspects of penicillin allergy. The direct penicilloylation of epsilon-amino groups by penicillin at pH 7.4

The aminolysis of penicillins by ε-amino groups at pH 7,4 is demonstrated. It is shown that penicillenic acid, formed spontaneously under these conditions from penicillins, does not contribute significantly to the penicilloylations observed. Penicillin therefore can directly form penicilloylamides under physiological conditions.