Inhibition of beta-lactamase II of Bacillus cereus by penamaldic derivatives of penicillins.

The penamaldic derivatives of amoxicillin, ampicillin, and penicillins G and V, stabilized with Zn(2+), were obtained from a methanolic medium. The enzymatic kinetic results show that the these derivatives elicit reversible inhibition of the enzyme metallo-beta-lactamase from Bacillus cereus, with inhibition constant values determined at pH 7.0 and 25 degrees C.