Nitrocefin

DescriptionThe generation of β-lactamases by bacteria affords resistance to several classes of β-lactam antibiotics, including penicillins and cephalosporins. Nitrocefin is a chromogenic cephalosporin substrate commonly used to detect β-lactamases in bacteria. The presence of β-lactamase activity is indicated by the appearance of a red color that is proportional in intensity to the original concentration of nitrocefin.

UsesNitrocefin is a chromogenic β-lactamase substrate that undergoes colour change from yellow to red as the amide bond in the β-Lactam ring is hydrolyzed by β-lactamase. Nitrocefin undergoes colour chang es induced by lactamases produced by Gram-positive and Gram-negative bacteria. Several studies have utilized the colour changing properties of Nitrocefin for the detection of β-lactamase activity from bacterial cell extracts by isoelectric focusing and spectroscopy. Nitrocefin has also been used in studies involving β-lactamase resistant antibiotics.

PreparationNitrocefin is a key reagent for high and low throughput assays of the activities of penicillin-binding proteins (PBPs) and β-lactamases, the former used for discovery of antibiotics and the latter for inhibitors of resistance determinants for β-lactam antibiotics. This compound is commercially available but is prohibitively expensive because of the circuitous routes to its synthesis. We describe herein a three-step synthesis of nitrocefin that gives an overall yield of 44%. This is a practical route to the synthesis of this key reagent for drug discovery.A Practical Synthesis of Nitrocefin