Differentiation and quantification of synthetic phosphatidylethanol (PEth) homologues by ¹H- and ¹³C-NMR in polar organic solvents.
Anal Bioanal Chem
; 406(19): 4735-44, 2014 Jul.
Article
in En
| MEDLINE
| ID: mdl-24866709
ABSTRACT
Various phosphatidylethanol (PEth) derivatives, the corresponding reversed positional isomers (RPI-PEths), lyso-PEth-160, and penta-deuterium-labeled PEth analogs (d5-PEths), were synthesized by enzyme-independent synthetic routes. A general solvent system consisting of a mixture of acetone-d6 and methanol-d4 (973; v/v) was found to provide a good solubilizing capacity and excellent hydrogen-1 NMR ((1)H-NMR) peak resolution of various PEth homologues. Analytical differentiation of PEth from the corresponding RPI-PEth by carbon-13 NMR ((13)C-NMR) was demonstrated by comparison of the (13)C-NMR signals of the carbonyl groups, the allylic positions, and of the ß-carbons. An exemplary stable long-term room temperature, DMSO-d6-based, and proton-sensitive quantitative nuclear magnetic resonance ((1)H-qNMR) independently quantified calibrator comprising PEth-160/181 for liquid chromatography (tandem) mass spectrometry (LC-MS/MS) analytical applications were prepared by employment of sodium dodecyl sulfate (SDS) as a solubilizing additive. In summary, novel hypothetically occurring PEth derivatives, e.g., RPI-PEths, have been independently synthesized with regio- and stereochemical control. Use of polar organic solvents, e.g., mixtures of acetone-d6 and methanol-d4 or DMSO-d6, improves spectral line shapes as compared to traditional hydrophobic solvents and allow for analytical differentiation between closely related PEth derivatives, as well as LC-MS/MS-independent concentration determination of dissolved single species by employment of (1)H-qNMR.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Solvents
/
Magnetic Resonance Spectroscopy
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Chromatography, Liquid
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Glycerophospholipids
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Spectrometry, Mass, Electrospray Ionization
Language:
En
Journal:
Anal Bioanal Chem
Year:
2014
Type:
Article