Synthesis, BSA Interaction and Antimicrobial Activities of two Amantadine Schiff Bases

A detailed characterization of the binding interaction and antimicrobial activities of two amantadine schiff bases, amantadine-2,4-dihydroxy benzaldehyde (ADB) and amantadine-3,5-di-tert-butyl salicylaldehyde (ADS), with bovine serum albumin (BSA) is demonstrated. It was found that both of them had an ability to quench the intrinsic fluorescence of BSA by forming a 1:1 ground-state complex, while ADB with a binding constant of about 105 L/mol much stronger than ADS. The binding distance r of ADB and ADS with BSA were calculated to be 2.5 and 4.2 nm, respectively, based on the theory of Forster's non-radiation energy transfer. The analysis of synchronous fluorescence spectra revealed that the microenvironment of amino acid residues was changed slightly after addition of ADB and ADS. Finally, the antimicrobial activities of the two compounds against Staphylococcus aureus and Escherichia coli were evaluated by agar diffusion method, which indicates that both of them are more active against S. aureus.