On‐line identification of unstable catalpol derivatives from<i> Jamesbrittenia fodina</i> by LC‐MS and LC‐NMR

Cogne, A.; Queiroz, Emerson Ferreira; Wolfender, Jean‐Luc; Marston, Andrew; Mavi, S.; Hostettmann, Kurt

doi:10.1002/pca.689

Cited by 27 publications

(19 citation statements)

References 11 publications

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“…The same signals were observed in the proton NMR analysis of each fraction, but with slightly different chemical shifts, which suggests that a possible mixing of the compounds may take place, like a mixture previously analyzed by Cogne et al [14]. It can also be observed that two different proton signals are observed for the p-coumaroyl moiety, corresponding to the two different isomers, as follows: H5/H9 (Z) (δ 7.71), and H5/H9 (E), (δ 7.48) respectively; H6/H8 (Z)/(E), (δ 6.81 and 6.77) ( Figure 5).…”

Section: Resultssupporting

confidence: 73%

A Novel Antioxidant Phenyl Disaccharide from Populus tremula Knotwood

et al. 2007

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Abstract:The complete characterization of two compounds obtained from the acetone extract of Populus tremula knotwood has been was achieved using LC-DAD-MS, MS/MS, IR and NMR. The new compounds were unequivocally identified as a mixture of the ester isomers of the (E) and (Z) p-coumarate of 1-O-rutinose. The isomers showed the capacity to inhibit lipid peroxidation induced by tert-butylhydroperoxide and to trap peroxyl radicals, as determined by a chemiluminescence method. These new phenyl disaccharides also showed a significant ORAC (oxygen radical absorbance capacity) value, i.e. 11.7 µM TE (Trolox Equivalents).

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Section: Resultssupporting

confidence: 73%

A Novel Antioxidant Phenyl Disaccharide from Populus tremula Knotwood

et al. 2007

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“…7) were analysed in the same way in the extract. 24 In the same extract, another cinnamic ester derivative 34a revealed a different type of instability. Indeed, 34a was found to be transformed after isolation and lyophilisation into two additional compounds 34a1 and 34a2 sharing the same UV and same molecular weight as their parent molecule 34a (Fig.…”

Section: Study Of Unstable Natural Products By On-flow and Stop-flow mentioning

confidence: 97%

“…24 A preliminary metabolite profiling study performed with LC/UV-DAD and LC/ESI-MS revealed the presence of various common cinnamic ester derivatives. On the basis of this first chemical screening results, the attention was focused on a pair of putative new isomeric compounds 32a/32b.…”

Section: Study Of Unstable Natural Products By On-flow and Stop-flow mentioning

confidence: 99%

Phytochemistry in the microgram domain—a LC–NMR perspective

Wolfender

Queiroz

Hostettmann

2005

Magnetic Reson in Chemistry

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Plants represent an extraordinary reservoir of novel molecules and there is currently a resurgence of interest in the vegetable kingdom as a possible source of new lead compounds for introduction into therapeutical screening programs. In order to discover potential new bioactive natural products, the dereplication of crude plant extracts performed prior to isolation work is of crucial importance for avoiding the isolation of a known constituent. In this respect, chemical screening strategies have been developed using hyphenated techniques (LC/UV-DAD, LC-MS and LC-NMR). In our laboratory, these techniques have been fully integrated into the isolation process and are used for the chemical screening of crude plant extracts in complement with on-line or at-line bioassays. LC-UV-MS is used as a first dereplication step in combination with UV and MS databases, while LC-NMR is performed in a second step for de novo on-line structure determination. This approach enables the partial or the complete on-line identification of natural products in complex matrices such as crude plant extracts. These methods also give a unique possibility to study unstable compounds, which rapidly degrade or which are not separable at a preparative level. In the multi-hyphenated approach used (hypernation), LC-NMR plays a key role since it provides the most detailed structural information. The relatively low sensitivity of this technique, however, requires that strategies for high loading of plant extracts are developed and compromises for solvent selection have to be made. For more demanding experiments, at-line strategies based on the microfractionation of the LC-peak of interest and recording of spectra in fully deuterated solvents in microflow probes represent a promising alternative.

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“…The mass of the compounds and the mass of lost fragment indicated the presence of prenylated isoflavanones or isoflavones; LC-NMR and MS-MS finally confirmed that result. In the publications of Schaller et al (2001) and Cogne et al (2003), crude plant extracts were analyzed by LC/ thermospray-MS and LC-UV-ESI/MS to determine the presence of certain classes of compounds such as diterpenic compounds and unstable cinnamic ester derivatives, respectively, whereas NMR experiments established the structure of isomeric pairs. Generally, it was observed that MS detection was more sensitive than NMR to detect the metabolites, but was less efficient for compound identification.…”

Section: Lc-ms For Metabolite Profilingmentioning

confidence: 99%

Mass spectrometry in metabolome analysis

Villas‐Bôas

Mas

Åkesson

et al. 2004

Mass Spectrometry Reviews

536

419

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In the post-genomic era, increasing efforts have been made to describe the relationship between the genome and the phenotype in cells and organisms. It has become clear that even a complete understanding of the state of the genes, messages, and proteins in a living system does not reveal its phenotype. Therefore, researchers have started to study the metabolome (or the metabolic complement of functional genomics). Within this context, mass spectrometry (MS) has increasingly occupied a central position in the methodologies developed for determination of the metabolic state. This review is mainly focused on the status of MS in the metabolome field, trying to direct the reader to the main approaches for analysis of metabolites, reviewing basic methodologies in sample preparation, and the most recent MS techniques introduced. Apart from the description of the different methods, this review will try to state a general comparison between the several different techniques that involve MS and metabolite analysis, and will highlight their limitations and preferred applicability.

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On‐line identification of unstable catalpol derivatives from Jamesbrittenia fodina by LC‐MS and LC‐NMR

Cited by 27 publications

References 11 publications

A Novel Antioxidant Phenyl Disaccharide from Populus tremula Knotwood

A Novel Antioxidant Phenyl Disaccharide from Populus tremula Knotwood

Phytochemistry in the microgram domain—a LC–NMR perspective

Mass spectrometry in metabolome analysis

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