Vancomycin Resistant Target Enzyme Vanx Inhibitors And Metal-beta-lactamase Detection Reagent Nitrocefin Synthesis And Characterization

The extensive use of vancomycin had led to the vancomycin-resistace of gram-positive bacteria, particularly in the phenomenon of threaten to human life and health by staphylococcus aureus seriously. Previous studies reveal that, VanX had played an important role in vancomycin resistance in the hydrolysis of D-Ala-D-Ala dipeptide and it is a potential drug target.With the multistep reactions we synthesized an important intermediate compound methyl 1-(benzyl amide carbonyl) ethyl phosphonate. Then the compound occured nucleophilic substitution reaction with a variety of amino acid methyl esters, and five kinds of phosphonamidate compounds were obtained by removing protection groups finally.We evaluated biological activities of these compounds by MIC experiments. The results showed that the compound 6a has inhibitory activity to Staphylococcus aureus and MRSA2, comparison with presence of vancomycin, compound 6a makes MIC value 8 folds lower. This result indicated that the compound 6a possesses a high inhibitory activity to Staphylococcus aureus.We designed and synthesized D-leucine-p-nitroaniline, which is the substrate of vancomycin-resistant target enzymes VanX. UV-Vis spectra showed that the maximum absorption of D-leucine-p-nitroaniline is at 258 nm.Nitrocefin was synthesized with starting material ACLE-HCl and characterized by 1H NMR, 13C NMR, IR and UV-Vis. UV-Vis spectra shown that the maximal absorbance moves from 390 to 486 nm after Nitrocefin was hydrolyzed catalyzed by metallo-(3-lactamase L1. This result indicated that the Nitrocefin is a good detecting reagent for the detection of metallo-p-lactamase and antibiotic resistant bacteria.