The effect of complexation of 3-formylrifamycin SV macrocyclic ether derivatives with metal cations and small nitrogen-containing organic molecules on antibacterial activity against S. aureus and S. epidermidis

Authors:

• Piotr Przybylski,
• Krystian Krzysztof Pyta,
• Dominika Czerwonka,
• Marcelina M. Kubicka,
• Marzena Gajecka

Abstract

Spectroscopic studies of ether rifamycins (1-9) have shown that all these compounds tend to be zwitterions with different localizations of intramolecularly transferred proton, which influences their solubility and log P values. According to ESI MS studies, rifamycins 3 and 4 form complexes with Li⁺ or Na⁺, while the other ones (7-9) coordinate small organic molecules, which can be further replaced by Na⁺ cation. Biological assays revealed that the use of 7-9 in the form of complexes with small organic molecules improves their antibacterial potency as a result of changed: log P, solubility and binding mode with bacterial RNA polymerases.