Standardless identification of selenocystathionine and its γ-glutamyl derivatives in monkeypot nuts by 3D liquid chromatography with ICP-MS detection followed by nanoHPLC–Q-TOF-MS/MS

Dernovics, Mihály; García-Barrera, Tamara; Bierła, Katarzyna; Preud’homme, Hugues; Łobiński, Ryszard

doi:10.1039/b618637h

Cited by 34 publications

(39 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on XANES alone, SeMet, MeSeCys, and SeCyst cannot be distinguished (all contain C-Se-C), and thus it is possible that this minor organic fraction was SeCyst. Mass spectrometry studies did indeed reveal the presence of SeCyst in B. juncea, Lecythis minor, and Arabidopsis, all secondary accumulators or nonaccumulator plants ( MontesBayon et al, 2002;Dernovics et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Freeman

Tamaoki²,

Stushnoff³

et al. 2010

Plant Physiol.

212

187

View full text Add to dashboard Cite

The molecular mechanisms responsible for selenium (Se) tolerance and hyperaccumulation were studied in the Se hyperaccumulator Stanleya pinnata (Brassicaceae) by comparing it with the related secondary Se accumulator Stanleya albescens using a combination of physiological, structural, genomic, and biochemical approaches. S. pinnata accumulated 3.6-fold more Se and was tolerant to 20 mM selenate, while S. albescens suffered reduced growth, chlorosis and necrosis, impaired photosynthesis, and high levels of reactive oxygen species. Levels of ascorbic acid, glutathione, total sulfur, and nonprotein thiols were higher in S. pinnata, suggesting that Se tolerance may in part be due to increased antioxidants and up-regulated sulfur assimilation. S. pinnata had higher selenocysteine methyltransferase protein levels and, judged from liquid chromatography-mass spectrometry, mainly accumulated the free amino acid methylselenocysteine, while S. albescens accumulated mainly the free amino acid selenocystathionine. S. albescens leaf x-ray absorption near-edge structure scans mainly detected a carbon-Se-carbon compound (presumably selenocystathionine) in addition to some selenocysteine and selenate. Thus, S. albescens may accumulate more toxic forms of Se in its leaves than S. pinnata. The species also showed different leaf Se sequestration patterns: while S. albescens showed a diffuse pattern, S. pinnata sequestered Se in localized epidermal cell clusters along leaf margins and tips, concentrated inside of epidermal cells. Transcript analyses of S. pinnata showed a constitutively higher expression of genes involved in sulfur assimilation, antioxidant activities, defense, and response to (methyl)jasmonic acid, salicylic acid, or ethylene. The levels of some of these hormones were constitutively elevated in S. pinnata compared with S. albescens, and leaf Se accumulation was slightly enhanced in both species when these hormones were supplied. Thus, defense-related phytohormones may play an important signaling role in the Se hyperaccumulation of S. pinnata, perhaps by constitutively up-regulating sulfur/Se assimilation followed by methylation of selenocysteine and the targeted sequestration of methylselenocysteine.

show abstract

Section: Discussionmentioning

confidence: 99%

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Freeman

Tamaoki²,

Stushnoff³

et al. 2010

Plant Physiol.

212

187

View full text Add to dashboard Cite

show abstract

“…LC-MS of 1.7-to 2.0-min Se-containing fractions with a mass spectrum matching SeCyst in cladode (A) and fruit juice (B). The published mass spectrum for SeCyst is shown in C (Dernovics et al, 2007;Freeman et al, 2010). tissues without having to extract or pretreat the samples.…”

Section: Discussionmentioning

confidence: 99%

“…SeCyst is a freely pooled selenoamino acid in many secondary Se accumulator plants and has been well documented in both secondary Se accumulator and nonaccumulator plant species, including but not limited to Brassica juncea, Lecythis minor (monkey pot nut), Morinda reticulate, Stanleya albescens, and Arabidopsis (Peterson and Butler, 1971;Montes-Bayon et al, 2002;Dernovics et al, 2007;Freeman et al, 2010). SeCyst is a metabolic intermediate between SeCys and SeMet, and both amino acids can be toxic to plants when incorporated into protein (for review, see Pickering et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…In native western Se-hyperaccumulator plants, which can accumulate 100-fold more Se than normal plants, Se misincorporation is prevented by the methylation of SeCys into Se-methyl-SeCys, which may be further converted to g-glutamyl-Se-methyl-SeCys (Dunnill and Fowden, 1967;Brown and Shrift, 1981; for review, see Sors et al, 2005). Additionally, selenocystathionine (SeCyst) was found to be accumulated at low concentrations in hyperaccumulator plants, in secondary accumulator plants, and in trace amounts in nonaccumulator plants (Shrift and Virupaksha, 1965;Peterson and Butler, 1971;Kotrebai et al, 2000;Montes-Bayon et al, 2002;Dernovics et al, 2007). There appears to be a clear potential for producing value-added Se-enriched Opuntia as a low-maintenance drought-tolerant crop with nutritional and health benefits.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Selenium Accumulation, Distribution, and Speciation in Spineless Prickly Pear Cactus: A Drought- and Salt-Tolerant, Selenium-Enriched Nutraceutical Fruit Crop for Biofortified Foods

Bañuelos

Fakra²,

Walse³

et al. 2010

Plant Physiol.

View full text Add to dashboard Cite

The organ-specific accumulation, spatial distribution, and chemical speciation of selenium (Se) were previously unknown for any species of cactus. We investigated Se in Opuntia ficus-indica using inductively coupled plasma mass spectrometry, microfocused x-ray fluorescence elemental and chemical mapping (mXRF), Se K-edge x-ray absorption near-edge structure (XANES) spectroscopy, and liquid chromatography-mass spectrometry (LC-MS). mXRF showed Se concentrated inside small conic, vestigial leaves (cladode tips), the cladode vasculature, and the seed embryos. Se K-edge XANES demonstrated that approximately 96% of total Se in cladode, fruit juice, fruit pulp, and seed is carbon-Se-carbon (C-Se-C). Micro and bulk XANES analysis showed that cladode tips contained both selenate and C-Se-C forms. Inductively coupled plasma mass spectrometry quantification of Se in high-performance liquid chromatography fractions followed by LC-MS structural identification showed selenocystathionine-to-selenomethionine (SeMet) ratios of 75:25, 71:29, and 32:68, respectively in cladode, fruit, and seed. Enzymatic digestions and subsequent analysis confirmed that Se was mainly present in a "free" nonproteinaceous form inside cladode and fruit, while in the seed, Se was incorporated into proteins associated with lipids. mXRF chemical mapping illuminated the specific location of Se reduction and assimilation from selenate accumulated in the cladode tips into the two LC-MS-identified C-Se-C forms before they were transported into the cladode mesophyll. We conclude that Opuntia is a secondary Se-accumulating plant whose fruit and cladode contain mostly free selenocystathionine and SeMet, while seeds contain mainly SeMet in protein. When eaten, the organic Se forms in Opuntia fruit, cladode, and seed may improve health, increase Se mineral nutrition, and help prevent multiple human cancers.

show abstract

“…1e) in monkeypot nuts (Lecythis minor), and γ-glutamylselenocystathionine was identified by HPLC-ESI-quadrupole and time-of-flight tandem MS (HPLC-ESI-Q-TOF). 56) SeHcy is methylated by methyltransferase (Met synthase) to form SeMet with N 5 -methyltetrahydrofolate as the methyl group donor. 57) As an alternate pathway, SeHcy is conjugated with another O-phosphohomoserine to form selenohomolanthionine (SeHLan, Fig.…”

Section: Selenoamino Acids In Se-accumulating Plantsmentioning

confidence: 99%

Selenometabolomics Explored by Speciation

Ogra

Anan

2012

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

Selenium (Se) belongs to the same group as sulfur in the periodic table but possesses certain chemical properties characteristic of a metal. It is an essential element in animals but becomes severely toxic when the amount ingested exceeds the required level. On the other hand, Se is not essential in plants although some plants are Se hyperaccumulators. Se changes into several chemical forms when metabolized. Thus, the identification of selenometabolites would enable us to formulate a metabolic chart of Se. Recently, speciation analysis by hyphenated techniques has contributed immensely to the study of selenometabolomes, i.e., the entirety of selenometabolites. Indeed, speciation has unveiled some unique selenometabolites in biological samples. The aim of this review is to present newly identified selenometabolites in animals and plants by speciation using hyphenated techniques and to delineate the perspectives of Se biology and toxicology from the viewpoint of speciation.

show abstract

Standardless identification of selenocystathionine and its γ-glutamyl derivatives in monkeypot nuts by 3D liquid chromatography with ICP-MS detection followed by nanoHPLC–Q-TOF-MS/MS

Cited by 34 publications

References 39 publications

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

Selenium Accumulation, Distribution, and Speciation in Spineless Prickly Pear Cactus: A Drought- and Salt-Tolerant, Selenium-Enriched Nutraceutical Fruit Crop for Biofortified Foods

Selenometabolomics Explored by Speciation

Contact Info

Product

Resources

About