Abstract
The power of NMR in elucidating the structure of isolated natural or synthetic compounds is well established. In recent years, NMR has also become an important tool for the qualitative and quantitative analysis of complex mixtures such as herbal medicines. The combination of 1H NMR and multivariate analysis, quite often used in metabolomics, leads to a metabolite fingerprint that can be used for quality control and identification of the origin (e.g. geographical or supplier). Compared with other methods and despite its relatively low intrinsic sensitivity, NMR has the advantages of simple sample preparation, high robustness, and non-selectivity thus providing global information in a single analysis but also specific structural characterization. Several examples of the application of 1H NMR in the quality control of herbal materials will be reviewed for highlighting the usefulness, advantages and limitations of NMR. The article will conclude on the Diffusion Ordered Spectroscopy 1H NMR method that can be regarded as a “virtual chromatography” for screening adulterations of herbal medicines.
Keywords: Adulteration, DOSY NMR, Herbal medicines, HPLC-NMR, Metabolomics, NMR, Quantitative NMR, virtual chromatography, Thin Layer Chromatography, High-Performance Liquid Chromatography, Diode Array Detection, Mass Spectrometry, Gas Chromatography, capillary electrophoresis, Fourier-Transform Infra-Red, Near Infra-Red, Nuclear Magnetic Resonance, Diffusion Ordered Spectroscopy, Hypericum perforatum, flavonols, phloroglucinols, naphthodianthrones, chlorogenic acids, sucrose, lipids, polyphenols, kava-kava, Piper methysticum, correlation spectroscopy, heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation, Lamiaceae family, solid-phase extraction, Kanahia laniflora, kaempferol, quercetin, isorhamnetin, N-methyl-laudanidinium acetate, Corydalis solida, hyperfirin, adhyperfirin, Neolitsea sericea var. aurata, Sephadex LH-20, Phyllanthus reticulatus, Hubertia ambavilla, Hubertia tomentosa, Haplophyllum acutifolium, Ephedra
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