D-Histidine

D-Histidine is an antibacterial anti-biofilm agent that targets bacterial quorum sensing systems (e.g., RhlI/RhlR pathway). It non-covalently binds bacterial regulatory factors or copper ion complexes, selectively inhibiting biofilm formation and motility. D-Histidine downregulates quorum sensing genes, reduces virulence factor synthesis (e.g., alginate, proteases), interferes with bacterial membrane stability, inhibits biofilm formation, promotes mature biofilm disintegration, and enhances antibiotic sensitivity. It's also an efficient catalyst for salt-induced peptide formation (SIPF) by forming a complex with Cu2+, promoting amino acid condensation to dipeptides (e.g., dialanine, dilysine).