Vancomycin-Lipopeptide Conjugates with High Antimicrobial Activity on Vancomycin-Resistant Enterococci

Area of Science:

• Microbiology
• Medicinal Chemistry
• Pharmacology

Background:

• Multidrug-resistant bacteria pose a significant global health threat, with limited last-resort treatment options.
• Vancomycin, a crucial glycopeptide antibiotic, faces resistance challenges, necessitating novel therapeutic strategies.

Purpose of the Study:

• To develop and evaluate structurally modified vancomycin conjugates with enhanced antimicrobial activity against resistant bacteria.
• To investigate the structure-activity relationship of vancomycin-lipopeptide conjugates, focusing on modification sites and fatty acid chain length.

Main Methods:

• Synthesis of vancomycin conjugates by structural modification with polycationic peptides and fatty acid conjugation.
• Antimicrobial activity testing against vancomycin-resistant enterococci.
• In vitro and in vivo cytocompatibility assessments.
• Radiolabeling for in vivo pharmacokinetic and biodistribution studies in Wistar rats using molecular imaging.

Main Results:

• Synthesized vancomycin-lipopeptide conjugates demonstrated high antimicrobial potential against vancomycin-resistant enterococci.
• Antimicrobial activity correlated with the length of the attached fatty acid chain.
• Conjugates exhibited good in vitro and in vivo cytocompatibility.
• Improved biodistribution compared to vancomycin was observed, with a shift from renal to hepatobiliary excretion for the most potent conjugate.

Conclusions:

• Structural modification of existing antibiotics like vancomycin is a viable strategy to create potent agents against multidrug-resistant bacteria.
• Vancomycin-lipopeptide conjugates represent a promising class of compounds with potential for treating severe resistant infections.
• The modified compounds offer an improved pharmacokinetic and biodistribution profile compared to the parent drug.