Modulators of antibiotic activity from Ipomoea murucoides.
Reinvestigation of the CHCl3-soluble extract from the flowers of Ipomoea murucoides, through preparative-scale recycling HPLC, yielded three pentasaccharides of 11-hydroxyhexadecanoic acid, murucoidins XVII-XIX, in addition to the known murucoidin III and V, all of which were characterized by NMR spectroscopy and mass spectrometry. These compounds were found to be macrolactones of the known pentasaccharides simonic acid B and operculinic acid A. The acylating groups corresponded to acetic, (2S)-methyl-butyric, (E)-cinnamic and octanoic acids. The esterification sites were established at the C-2 of the second rhamnose and C-3 and C-4 of the third rhamnose. The aglycone lactonization was placed at C-2 or C-3 of the first rhamnose. Bioassays for modulation of antibiotic activity were performed against multidrug-resistant strains of Staphylococcus aureus, Escherichia coli Rosetta-gami, and two nosocomial pathogens: Salmonella enterica sv. Typhi and Shigella flexneri. The tested glycolipids did not act as cytotoxic (IC50>4 μg/mL) nor as antimicrobial (MIC>128 μg/mL) agents. However, they exerted a potentiation effect on clinically useful antibiotics against the tested bacteria by increasing their antibiotic susceptibility up to four-fold at concentrations of 25 μg/mL.
Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City 04510DF, Mexico.
Berenice
B
Corona-Castañeda
Lilia
L
Chérigo
Mabel
M
Fragoso-Serrano
Simon
S
Gibbons
Rogelio
R
Pereda-Miranda
D000215:Acylation; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002210:Caprylates / Q000737:chemistry / Q000494:pharmacology; D002934:Cinnamates / Q000737:chemistry / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects; D004951:Esterification; D035264:Flowers; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology; D041743:Herb-Drug Interactions; D027741:Ipomoea / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D015394:Molecular Structure; D009844:Oligosaccharides / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D019779:Salmonella enterica / Q000187:drug effects; D012763:Shigella flexneri / Q000187:drug effects
D000900:Anti-Bacterial Agents; D002210:Caprylates; D002934:Cinnamates; D006027:Glycosides; D007783:Lactones; D009844:Oligosaccharides; D010936:Plant Extracts; C570671:murucoidin V; C482480:operculinic acid; C029010:cinnamic acid; C031492:octanoic acid
Convolvulaceae; Glycolipids; Gram-negative bacteria; Gram-positive bacteria; Ipomoea murucoides; Multidrug-resistance; Structural spectroscopy