Inhibition of the β-lactamases of Escherichia coli and Klebsiella aerogenes by semi-synthetic penicillins

摘要: 1. A new automated micro-iodometric method is described for screening compounds inhibitory action against beta-lactamase enzymes. 2. Over 1000 semi-synthetic penicillins were tested activity the of Escherichia coli B11 and 18 showed a fractional inhibition similar to or higher than that methicillin. 3. The best inhibitors alkoxy- halogen-substituted phenyl-, naphthyl- quinolyl-penicillins. 2-Isopropoxy-1-naphthylpenicillin (BRL 1437) was clearly had K(i) value about 1% 4. E. by BRL 1437 shown be reversible competitive. 0.004mum K(i)/K(m) with ampicillin p-hydroxyampicillin 2333) 0.0001. K(m) V(max.) values determined beta-lactamases Klebsiella aerogenes variety penicillins. Cell-bound solubilized enzymes gave values. 5. superior cloxacillin methicillin live, fully grown cultures several strains K. aerogenes. Of group most stable B11.