2 research outputs found
<sup>13</sup>C NMR and LC-MS Profiling of Stilbenes from Elicited Grapevine Hairy Root Cultures
Resveratrol and related oligostilbenes
are defense molecules produced
by grapevine in response to stresses including various elicitors or
signal molecules. Together with their prominent role <i>in planta,</i> these compounds have been the center of much attention in recent
decades due to their pharmacological properties. The cost-effective
production of resveratrol derivatives such as viniferins or more structurally
complex stilbene oligomers remains a challenging task. In this study,
the chemical diversity of stilbenes produced by <i>Vitis vinifera</i> Pinot Noir hairy roots was investigated after elicitation for 4
days with a mixture of methyl jasmonate (100 ÎŒM) and cyclodextrins
(50 mM). Two crude extracts obtained from the culture medium and from
the hairy roots were fractionated by centrifugal partition chromatography.
The fractions were chemically investigated by two complementary identification
approaches involving a <sup>13</sup>C NMR-based dereplication method
and liquid chromatography coupled to mass spectrometry (LC-MS). In
total, groups of 21 and 18 molecules, including flavonoids and stilbenes,
were detected in the culture medium and root extracts, respectively.
These included resveratrol monomers, dimers, trimers, and a tetramer,
thus highlighting the ability of elicited hairy root culture systems
to synthesize a wide diversity of secondary metabolites of pharmaceutical
significance. The main compounds were unambiguously identified as <i>trans</i>-resveratrol, Δ-viniferin, <i>trans</i>-piceatannol, pallidol, scirpusin A, eriodictyol, naringenin, vitisin
B, and maackin
Determination of Multimodal Isotopic Distributions: The Case of a <sup>15</sup>N Labeled Protein Produced into Hairy Roots
Isotopic labeling is widely used
in various fields like proteomics,
metabolomics, fluxomics, as well as in NMR structural studies, but
it requires an efficient determination of the isotopic enrichment.
Mass spectrometry is the method of choice for such analysis. However,
when complex expression systems like hairy roots are used for production,
multiple populations of labeled proteins may be obtained. If the isotopic
incorporation determination is actually well-known for unimodal distributions,
the multimodal distributions have scarcely been investigated. Actually,
only a few approaches allow the determination of the different labeled
population proportions from multimodal distributions. Furthermore,
they cannot be used when the number of the populations and their respective
isotope ratios are unknown. The present study implements a new strategy
to measure the <sup>15</sup>N labeled populations inside a multimodal
distribution knowing only the peptide sequence and peak intensities
from mass spectrometry analyses. Noteworthy, it could be applied to
other elements, like carbon and hydrogen, and extended to a larger
range of biomolecules