Title
Structure elucidation of anti-methicillin resistantStaphylococcus aureus (MRSA) flavonoids from balsam poplar buds
Author
François Simard, Charles Gauthier, Jean Legault, Serge Lavoie, Vakhtang Mshvildadze, André Pichette
Year
2016
Journal
Bioorganic & Medicinal Chemistry
Abstract
There is nowadays an urgent need for developing novel generations of antibiotic agents due to the increased resistance of pathogenic bacteria. As a rich reservoir of structurally diverse compounds, plant species hold promise in this regard. Within this framework, we isolated a unique series of antibacterial flavonoids, named balsacones N–U, featuring multiple cinnamyl chains on the flavan skeleton. The structures of these compounds, isolated as racemates, were determined using extensive 1D and 2D NMR analysis in tandem with HRMS. Balsacones N–U along with previously isolated balsacones A–M were evaluated for their antibacterial activity against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA). Several of the tested balsacones were potent anti-MRSA agents showing MIC values in the low micromolar range. Structure–activity relationships study highlighted some important parameters involved in the antibacterial activity of balsacones such as the presence of cinnamyl and cinnamoyl chains at the C-3 and C-8 positions of the flavan skeleton, respectively. These results suggest that balsacones could represent a potential novel class of naturally occurring anti-MRSA agents.
Instrument
J-815
Keywords
Circular dichroism, Stereochemistry, Medicinal