Combating multidrug-resistance in : a G-quadruplex binding inhibitor of efflux pump and its bio-orthogonal assembly.

Antibiotic resistance poses a significant global health threat, necessitating innovative strategies to combat multidrug-resistant bacterial infections. , a pathogen responsible for various infections, harbors highly conserved DNA quadruplexes in genes linked to its pathogenesis. In this study, we introduce a novel approach to counter antibiotic resistance by stabilizing G-quadruplex structures within the open reading frames of key resistance-associated genes (, and ). We synthesized , a bis-anthracene derivative, using Cu(I)-catalyzed azide-alkyne cycloaddition, which exhibited remarkable binding and stabilization of the G-quadruplex in the gene responsible for drug efflux. effectively permeated multidrug-resistant strains, leading to a substantial 12.5-fold reduction in ciprofloxacin resistance. Furthermore, downregulated gene expression, enhancing drug retention within bacterial cells. Remarkably, the G-quadruplex cloned into the pET28a(+) plasmid transformed into BL21 cells can template Cu-free bio-orthogonal synthesis of from its corresponding alkyne and azide fragments. This study presents a pioneering strategy to combat antibiotic resistance by genetically reducing drug efflux pump expression through G-quadruplex stabilization, offering promising avenues for addressing antibiotic resistance.