Antibacterial activities of metabolites from Platanus occidentalis (American Sycamore) against fish pathogenic bacteria

Abstract

One approach to the management of common fish diseases in aquaculture is the use of antibioticladen feed. However, there are public concerns about the use of antibiotics in agriculture and the potential development of antibiotic resistant bacteria. Therefore, the discovery of other environmentally safe natural compounds as alternatives to antibiotics would benefit the aquaculture industries. Four natural compounds, commonly called platanosides,isolated from the leaves of the American sycamore (Platanus occidentalis) tree were evaluated using a rapid bioassay for their antibacterial activities against common fish pathogenic bacteria including Flavobacterium columnare, Edwardsiella ictaluri, Aeromonas hydrophila, and Streptococcus iniae. The four isomers and a mixture of all four isomers were strongly antibacterial against isolates of F. columnare and S. iniae. Against F. columnare ALM-00-173, 3 and 4 showed the strongest antibacterial activities, with 24-h 50% inhibition concentration (IC 50 ) values of 2.13 ± 0.11 and 2.62 ± 0.23 mg/L, respectively. Against S. iniae LA94-426, 4 had the strongest antibacterial activity, with 24-h IC 50 of 1.87 ± 0.23 mg/L. Neither a mixture of the isomers nor any of the individual isomers were antibacterial against isolates of E. ictaluri and A. hydrophila at the This is an open

UHPLC-ESI-QqTOF Analysis and In Vitro Rumen Fermentation for Exploiting Fagus sylvatica Leaf in Ruminant Diet

“…The interest in these compounds is mainly related to their antimicrobial activity, so much so that antibacterial kaempferol coumaroyl rhamnosides, commonly called platanosides, were previously isolated from the leaves of Platanus occidentalis [ 33 ]. Kaempferol-3-O-(bis-p-coumaroyl) rhamnoside was also from Persea lingue and was found to exert efflux inhibitory activity towards the NorA transporter of Staphylococcus aureus [ 34 ], whereas kaempferol 7-O-(2,3-di-E-p-coumaroyl-α-L-rhamnoside) was isolated from the flowers and fruit of Tetrapanax papyriferus [ 35 ].…”