Interplay between Supramolecular and Coordination Interactions in Synthetic Amphiphiles: Triggering Metal Starvation and Anchorage onto MRSA Cell Surface

The present work highlights the implications of supramolecular interaction and metal coordination on the self-assembly behavior and bactericidal potential of salicaldehyde-(C1) and napthaldehyde-based (C2) amphiphiles against methicillin-resistant Staphylococcus aureus (MRSA). LB trough and atomic force microscope (AFM) analysis indicated the propensity of the amphiphiles to form a monolayer as well as spherical aggregates, with the critical micelle concentration (CMC) for C2 (7.0 µM) being lower than C1 (18.5 µM) in water. Formation of amphiphile-metal complex was evidenced by ESI-MS, FTIR, FETEM-EDX and ITC analysis. Growth of S. aureus MRSA 100 cells was remarkably impaired in presence of 5.0 µM C1 or 20 µM C2 as compared to free cells or cells grown in presence of equivalent levels of amphiphile-metal complexes, suggesting that the amphiphiles perhaps sequester metal and induce metal starvation in MRSA. C1 and C2 rendered superior membrane damage in MRSA and were less toxic to human embryonic kidney (...