SYNTHESIS, PURIFICATION AND KINETIC-PROPERTIES OF FLUORESCEIN-LABELEDPENICILLINS

The synthesis and properties of six fluorescein-labelled penicillins a re reported. The two isomers of fluoresceyl-glycyl-6-amino-penicillani c acid are probably the best compounds to use for detection of all the penicillin-binding proteins (PBPs) present in a bacterial membrane pr eparation. However, the derivatives of ampicillin were much more effic ient against Enterobacter aerogenes PBP3. The two isomers obtained whe n a commercial mixture of the two isomers of carboxyfluorescein was us ed most often exhibited similar properties, but the Streptomyces R61 e xtracellular DD-peptidase was only efficiently acylated by the 5'-carb oxyfluorescein derivative of glycyl-6-aminopenicillanic acid.