Comprehensive analysis of commercial willow bark extracts by new technology platform: Combined use of metabolomics, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy and high-resolution radical scavenging assay
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark Journal of Chromatography A
(Impact Factor: 4.17).
09/2012; 1262:130-7. DOI: 10.1016/j.chroma.2012.09.013
Here, proof-of-concept of a new analytical platform used for the comprehensive analysis of a small set of commercial willow bark products is presented, and compared with a traditional standardization solely based on analysis of salicin and salicin derivatives. The platform combines principal component analysis (PCA) of two chemical fingerprints, i.e., HPLC and (1)H NMR data, and a pharmacological fingerprint, i.e., high-resolution 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS(+)) reduction profile, with targeted identification of constituents of interest by hyphenated HPLC-solid-phase extraction-tube transfer NMR, i.e., HPLC-SPE-ttNMR. Score plots from PCA of HPLC and (1)H NMR fingerprints showed the same distinct grouping of preparations formulated as capsules of Salix alba bark and separation of S. alba cortex. Loading plots revealed this to be due to high amount of salicin in capsules and ampelopsin, taxifolin, 7-O-methyltaxifolin-3'-O-glucoside, and 7-O-methyltaxifolin in S. alba cortex, respectively. PCA of high-resolution radical scavenging profiles revealed clear separation of preparations along principal component 1 due to the major radical scavengers (+)-catechin and ampelopsin. The new analytical platform allowed identification of 16 compounds in commercial willow bark extracts, and identification of ampelopsin, taxifolin, 7-O-methyltaxifolin-3'-O-glucoside, and 7-O-methyltaxifolin in S. alba bark extract is reported for the first time. The detection of the novel compound, ethyl 1-hydroxy-6-oxocyclohex-2-enecarboxylate, is also described.
Available from: Mohamed A Farag
- "Classification of grapes cultivars 1 H, JRES NMR Phenolic acids  Classification of licorice species 1 H, 2D ROESY Triterpenoid saponins  Classification of hops cultivars 2D HMBC Bitter acids  Classification of Hypericum species 1 H, HSQC, HMBC Phloroglucinol derivatives  Classification of Salix species in relation to activity LC–SPE–NMR DPPH assay Salicin, phenolic compounds  "
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ABSTRACT: Today, most investigations of the plant metabolome tend to be based on either nuclear magnetic
resonance (NMR) spectroscopy or mass spectrometry (MS), with or without hyphenation with
chromatography. Although less sensitive than MS, NMR provides a powerful complementary
technique for the identification and quantification of metabolites in plant extracts. NMR spectroscopy,
well appreciated by phytochemists as a particularly information-rich method, showed
recent paradigm shift for the improving of metabolome(s) structural and functional characterization
and for advancing the understanding of many biological processes. Furthermore, two
dimensional NMR (2D NMR) experiments and the use of chemometric data analysis of
NMR spectra have proven highly effective at identifying novel and known metabolites that correlate
with changes in genotype or phenotype. In this review, we provide an overview of the
development of NMR in the field of metabolomics with special focus on 2D NMR spectroscopic
techniques and their applications in phytomedicines quality control analysis and drug
discovery from natural sources, raising more attention at its potential to reduce the gap between
the pace of natural products research and modern drug discovery demand.
Journal of Advanced Research 11/2014; 6(1). DOI:10.1016/j.jare.2014.10.003
- "Identification of bioactive constituents in plant extracts can be advanced by using analytical-scale high-resolution bioactivity profiling , aiming at pinpointing bioactive constituents for subsequent structure elucidation by hyphenated analytical techniques. This has recently been demonstrated by Staerk and coworkers, using microplate-based high-resolution bioassays combined with hyphenated high-performance liquid chromatography – high-resolution mass spectrometry – solid-phase extraction – nuclear magnetic resonance spectroscopy, i.e., HR-bioassay/HPLC–HRMS–SPE– NMR, for expedited identification of radical scavengers (Agnolet et al., 2012; Wiese et al., 2013; Wubshet et al., 2013a), monoamine oxidase A inhibitors (Grosso et al., 2013), antibacterial inhibitors (Liu et al., 2014) and a-glucosidase inhibitors (Schmidt et al., 2012, 2014; Wubshet et al., 2013b) in herbal remedies and food. "
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ABSTRACT: Inhibition of the necrotizing hyaluronidase, phospholipase A2 and protease enzymes in four snake venoms by crude water and ethanol extracts of 88 plant species used against snakebites in traditional Chinese medicine was measured. High-resolution hyaluronidase inhibition profiles were constructed for the 22 plants showing highest hyaluronidase inhibition, and the results were used to guide subsequent structural analysis towards specific hyaluronidase inhibitors. Structural analysis was performed by high-performance liquid chromatography, high-resolution mass spectrometry, solid-phase extraction and nuclear magnetic resonance spectroscopy, i.e., HPLC-HRMS-SPE-NMR. This allowed identification of four non-tannin inhibitors, i.e., lansiumamide B (6) from Clausena excavata Burm.f., myricetin 3-O-β-d-glucopyranoside (7) from Androsace umbellata (Lour.) Merr., and vitexin (8) and 4',7-dihydroxy-5-methoxyflavone-8-C-β-d-glucopyranoside (9) from Oxalis corniculata L. Absolute configuration of 2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide (1) was determined using the Mosher method, which revealed two enantiomers, i.e., (2S,3R)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide and (2R,3S)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide with a ratio of 7:3.
Journal of Ethnopharmacology 07/2014; 155(2). DOI:10.1016/j.jep.2014.07.019 · 3.00 Impact Factor
Available from: Urszula Gawlik-Dziki
- "Antioxidant activity of Salix bark was widely studied [24, 26, 27], but comparative analysis of results was difficult due to different ways of its measure and expression. And so, antiradical activity of bark of S. aegyptiaca (depending on the extraction system) ranged from 10 to 105 mg quercetin equivalent/d DM . "
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ABSTRACT: The aim of this study was to investigate and to compare the extractability, bioaccessibility, and bioavailability in vitro of antioxidative compounds from bark of selected Salix species: S. alba (SA), S. daphnoides (SD), S. purpurea (SP), and S. daphnoides x purpurea (SDP) hybrid willow clones originating from their natural habitats and cultivated on the sandy soil. The highest amount of phenolic glycosides was found in the bark of SDP and SD. The best source of phenolics was bark of SDP. The highest content of flavonoids were found in SD bark samples, whereas the highest concentration of bioaccessible and bioavailable phenolic acids was determined in SDP bark. Bark of all tested Salix species showed significant antiradical activity. This properties are strongly dependent on extraction system and genetic factors. Regardless of Salix genotypes, the lowest chelating power was found for chemically-extractable compounds. Bark of all Salix species contained ethanol-extractable compounds with reducing ability. Besides this, high bioaccessibility and bioavailability in vitro of Salix bark phytochemicals were found. Obtained results indicate that extracts from bark tested Salix genotypes can provide health promoting benefits to the consumers; however, this problem requires further study.
The Scientific World Journal 02/2014; 2014:782763. DOI:10.1155/2014/782763 · 1.73 Impact Factor
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