title: Characterisation of antimicrobial extracts from dandelion root (Taraxacum officinale) using LC-SPE-NMR.
abstract: Plant extracts have traditionally been used as sources of natural antimicrobial compounds, although in many cases, the compounds responsible for their antimicrobial efficacy have not been identified. In this study, crude and dialysed extracts from dandelion root (Taraxacum officinale) were evaluated for their antimicrobial properties against Gram positive and Gram negative bacterial strains. The methanol hydrophobic crude extract (DRE3) demonstrated the strongest inhibition of microbial growth against Staphylococcus aureus, methicillin-resistant S. aureus and Bacillus cereus strains. Normal phase (NP) fractionation of DRE3 resulted in two fractions (NPF4 and NPF5) with enhanced antimicrobial activity. Further NP fractionation of NPF4 resulted in two fractions (NPF403 and NPF406) with increased antimicrobial activity. Further isolation and characterisation of compounds in NPF406 using liquid chromatography solid phase extraction nuclear magnetic resonance LC-SPE-NMR resulted in the identification of 9-hydroxyoctadecatrienoic acid and 9-hydroxyoctadecadienoic acid, while the phenolic compounds vanillin, coniferaldehyde and p-methoxyphenylglyoxylic acid were also identified respectively. The molecular mass of these compounds was confirmed by LC mass spectroscopy (MS)/MS. In summary, the antimicrobial efficacy of dandelion root extracts demonstrated in this study support the use of dandelion root as a source of natural antimicrobial compounds.
authors: Department of Food Biosciences, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland; Conway Institute of Biomolecular and Biomedical Research, UCD, Belfield, Dublin 4, Ireland.
authors: O
authors: O
authors: Kenny
authors: N P
authors: NP
authors: Brunton
authors: D
authors: D
authors: Walsh
authors: C M
authors: CM
authors: Hewage
authors: P
authors: P
authors: McLoughlin
authors: T J
authors: TJ
authors: Smyth
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects*; D002853:Chromatography, Liquid; D009682:Magnetic Resonance Spectroscopy; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects*; D053719:Tandem Mass Spectrometry; D031205:Taraxacum / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010636:Phenols; D010936:Plant Extracts
keywords: LC-MS/MS; LC-SPE-NMR; Taraxacum officinale; antimicrobial; flash chromatography; minimum inhibitory concentration