A Rationally Designed Sulfonium Lipoglycopeptide with Micelles Self-Assembly to Combat Multidrug Resistance via Dual Enhanced Cell Wall-Membrane Inhibition and T7SS Proteins Downregulation

Multidrug-resistant Gram-positive superbugs pose a significant menace to global public health, urgently demanding the advent of novel antibiotics. In this study, three biphenyl sulfonium lipoglycopeptides derived from vancomycin were rationally designed and synthesized to combat such resistance. Among them, the most promising derivative, BD-V-2, exhibited outstanding in vitro activity against a diverse array of refractory strains. Notably, in two highly challenging lethal sepsis models induced by MRSA and VREm (vanA), BD-V-2 achieved complete protection of the infected mice with remarkably low single-dose administrations of merely 7 and 2.5 mg/kg, respectively, vividly demonstrating its potent in vivo efficacy. Furthermore, its in vivo pharmacokinetic profile and toxicity assessment indicated favorable druggability. Interestingly, BD-V-2 was found to impart a novel self-assembly property into micelles. In addition, independent and synergistic mechanisms of action targeting the bacterial membrane, via phosphatidylglycerol (PG) interaction, and cell wall, via two more binding sites on lipid II, respectively, interpeptide bridge and pyrophosphate motif, were elucidated. Astonishingly, BD-V-2 was capable of significantly downregulating the expression of the type VII secretion system proteins, uncovering an unprecedented antivirulence mechanism for glycopeptide antibiotics. Collectively, these findings unraveled the hitherto unknown roles of the sulfonium strategy and established BD-V-2 as a highly prospective candidate for future pharmaceutical development.