title: Antibacterial Activities of Metabolites fromPlatanus occidentalis(American sycamore) against Fish Pathogenic Bacteria.
abstract: One approach to the management of common fish diseases in aquaculture is the use of antibiotic-laden 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, [kaempferol 3-O-α-L-(2″,3″-di-E-p-coumaroyl)rhamnoside (1), kaempferol 3-O-α-L-(2″-E-p-coumaroyl-3″-Z-p-coumaroyl)rhamnoside (2), kaempferol 3-O-α-L-(2″-Z-p-coumaroyl-3″-E-p-coumaroyl)rhamnoside (3), and kaempferol 3-O-α-L-(2″,3″-di-Z-p-coumaroyl)rhamnoside (4)] 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 includingFlavobacterium columnare,Edwardsiella ictaluri,Aeromonas hydrophila, andStreptococcus iniae. The four isomers and a mixture of all four isomers were strongly antibacterial against isolates ofF. columnareandS. iniae. AgainstF. columnareALM-00-173,3and4showed the strongest antibacterial activities, with 24-h 50% inhibition concentration (IC50) values of 2.13 ± 0.11 and 2.62 ± 0.23 mg/L, respectively. AgainstS. iniaeLA94-426,4had the strongest antibacterial activity, with 24-h IC50of 1.87 ± 0.23 mg/L. Neither a mixture of the isomers nor any of the individual isomers were antibacterial against isolates ofE. ictaluriandA. hydrophilaat the test concentrations used in the study. Several of the isomers appear promising for the potential management of columnaris disease and streptococcosis in fish.
authors: United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, National Center for Natural Products Research, Post Office Box 1848, Mississippi 38677, USA.
authors: Kevin K
authors: KK
authors: Schrader
authors: Departments of Pharmacognosy, School of Pharmacy, University of Mississippi, University, Mississippi 38677, USA; Pharmacology, Chemistry and Biochemistry Department, School of Pharmacy, University of Mississippi, University, Mississippi 38677, USA.
authors: Mark T
authors: MT
authors: Hamann
authors: Ironstone Separations, Inc., 147 County Road 245, Etta, Mississippi 38627, USA.
authors: James D
authors: JD
authors: McChesney
authors: Ironstone Separations, Inc., 147 County Road 245, Etta, Mississippi 38627, USA.
authors: Douglas L
authors: DL
authors: Rodenburg
authors: United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, National Center for Natural Products Research, Post Office Box 1848, Mississippi 38677, USA; Departments of Pharmacognosy, School of Pharmacy, University of Mississippi, University, Mississippi 38677, USA; Department of Chemistry of Natural Compounds, National Research Center, Dokki 12622, Cairo, Egypt.
authors: Mohamed A
authors: MA
authors: Ibrahim
keywords: Antibacterial; Channel catfish; Columnaris disease; Flavobacterium columnare; Kaempferol; Streptococcosis; Streptococcus iniae; Sycamore; platanoside