Inhibitors of Bacterial Multidrug Efflux Pumps from the Resin Glycosides ofIpomoea murucoides⊥

Chérigo, L., Pereda-Miranda, R., Fragoso-Serrano, M., Jacobo-Herrera, N., Kaatz, G.W. and Gibbons, S. (2008) Inhibitors of Bacterial Multidrug Efflux Pumps from the Resin Glycosides ofIpomoea murucoides⊥. Journal of Natural Products, 71 (6). pp. 1037-1045. 10.1021/np800148w.

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DOI: 10.1021/np800148w

Abstract

A reinvestigation of the CHCl3-soluble extract from flowers of the Mexican medicinal arborescent morning glory, Ipomoea murucoides, through preparative-scale recycling HPLC, yielded six new pentasaccharides, murucoidins VI - XI (1-6), as well as the known pescaprein III (7), stoloniferin I (8), and murucoidins I - V (9-13). Their structures were characterized through the interpretation of their NMR spectroscopic and FABMS data. Compounds 1-6 were found to be macrolactones of three known glycosidic acids identified as simonic acids A and B, and operculinic acid A, with different fatty acids esterifying the same positions, C-2 on the second rhamnose unit and C-4 on the third rhamnose moiety. The lactonization site of the aglycone was placed at C-2 or C-3 of the second saccharide unit. The esterifying residues were composed of two short-chain fatty acids, 2-methylpropanoic and (2S)-methylbutyric acids, and two long-chain fatty acids, n-dodecanoic (lauric) acid and the new (8R)-(-)-8-hydroxydodecanoic acid. For the latter residue, its absolute configuration was determined by analysis of its Mosher ester derivatives. All members of the murucoidin series exerted a potentiation effect of norfloxacin against the NorA overexpressing Staphylococcus aureus strain SA-1199B by increasing the activity 4-fold (8 μg/mL from 32 μg/mL) at concentrations of 5-25 μg/mL. Stoloniferin I (8) enhanced norfloxacin activity 8-fold when incorporated at a concentration of 5 μg/mL. Therefore, this type of amphipathic oligosaccharide could be developed further to provide more potent inhibitors of this multidrug efflux pump.

Item Type:Article
Departments, units and centres:Department of Pharmaceutical and Biological Chemistry > Department of Pharmaceutical and Biological Chemistry
ID Code:3074
Journal or Publication Title:Journal of Natural Products
Deposited By:Library Staff
Deposited On:23 Mar 2012 17:43
Last Modified:23 Mar 2012 17:43

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