Allium Chemistry: Identification of Selenoamino Acids in Ordinary and Selenium-Enriched Garlic, Onion, and Broccoli Using Gas Chromatography with Atomic Emission Detection

Cai, Xiao-Jia; Block, Eric; Uden, Peter C.; Zhang, Xing; Quimby, Bruce D.; Sullivan, James J.

doi:10.1021/jf00055a002

Cited by 151 publications

(123 citation statements)

References 22 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…Wheat (Triticum aestivum) grain grown in seleniferous soils accumulates selenomethionine (SeMet) and is one of the main dietary sources for Se (Lyons et al, 2005). Broccoli (Brassica oleracea var italica) has the ability to accumulate high level of Se-methylselenocysteine (SeMCys) and SeMet when grown on seleniferous soil (Cai et al, 1995). These selenoamino acids have been shown to be potent chemoprotective agents against cancer (Ip et al, 2000;Whanger, 2002).…”

mentioning

confidence: 99%

Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds

et al. 2009

View full text Add to dashboard Cite

Selenium (Se) is an essential micronutrient for animals and humans but becomes toxic at high dosage. Biologically based Se volatilization, which converts Se into volatile compounds, provides an important means for cleanup of Se-polluted environments. To identify novel genes whose products are involved in Se volatilization from plants, a broccoli (Brassica oleracea var italica) cDNA encoding COQ5 methyltransferase (BoCOQ5-2) in the ubiquinone biosynthetic pathway was isolated. Its function was authenticated by complementing a yeast coq5 mutant and by detecting increased cellular ubiquinone levels in the BoCOQ5-2-transformed bacteria. BoCOQ5-2 was found to promote Se volatilization in both bacteria and transgenic Arabidopsis (Arabidopsis thaliana) plants. Bacteria expressing BoCOQ5-2 produced an over 160-fold increase in volatile Se compounds when they were exposed to selenate. Consequently, the BoCOQ5-2-transformed bacteria had dramatically enhanced tolerance to selenate and a reduced level of Se accumulation. Transgenic Arabidopsis expressing BoCOQ5-2 volatilized three times more Se than the vector-only control plants when treated with selenite and exhibited an increased tolerance to Se. In addition, the BoCOQ5-2 transgenic plants suppressed the generation of reactive oxygen species induced by selenite. BoCOQ5-2 represents, to our knowledge, the first plant enzyme that is not known to be directly involved in sulfur/Se metabolism yet was found to mediate Se volatilization. This discovery opens up new prospects regarding our understanding of the complete metabolism of Se and may lead to ways to modify Se-accumulator plants with increased efficiency for phytoremediation of Se-contaminated environments.

show abstract

mentioning

confidence: 99%

Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds

et al. 2009

View full text Add to dashboard Cite

show abstract

“…In contrast, the findings of the previous author, Ip et al (2000), Kápolna & Fodor (2006) and Cai et al (1995) found that the main selenium form in the garlic, green onion, chive and broccoli enriched with selenium is the form of methyl-seleno-cysteine.…”

Section: Selenium Enrichment Possibilities Of Foods Of Plant Originmentioning

confidence: 70%

Production of selenium-enriched milk and dairy products

Csapó

Holló

et al. 2015

Acta Universitatis Sapientiae, Alimentaria

View full text Add to dashboard Cite

Abstract. Until the middle of the last century, selenium was considered to be toxic, but recently it turned out to be a micronutrient with important physiological effects, whose lack impedes the functioning of several enzymes, while in the case of a prolonged deficiency, disease processes can also occur in the body. Hungary belongs to the selenium-deficient regions in Europe; therefore, our aim was to contribute to the improvement of selenium supply of the population through increasing the selenium content of milk and dairy products. A daily supplementation of 1-6 mg organic selenium to the feed of dairy cows increases the selenium content of milk from the value of 18 μg/kg to 94 μg/kg in 8 weeks, decreasing again to the initial value in 6 weeks after stopping the supplementation.After producing various products from the control milk (18 μg/kg selenium content) and the selenium-enriched milk (53 μg/kg) obtained from dairy cattle fed on a feed supplemented with 2 mg selenium/day, we concluded that the selenium content of selenium-enriched milk compared to the products produced from the control milk increased from the value of 18.6 to 58.5 μg/kg in the case of yogurt, from 66.0 to 138.1 μg/kg in the case of telemea, from 80.8 to 163.7 μg/kg in the case of orda (urdȃ) and from 88.6 to 200.0 μg/kg in the case of semi-hard cheese obtained by mixed-coagulation. The selenium content of whey also increased significantly (from 8.8-9.7 μg/kg to 20.1-25.8 μg/kg), which could also be used as a food for people or feed for animals. According to our calculations, the selenium requirements of the developing organism could be satisfied by the consumption of 2-3 dl selenium-enriched milk until the age of 8 and with 4-6 dl selenium-enriched milk until the age of 20.

show abstract

“…When GC is coupled with AED, Se in target molecules is directly monitored by spectroscopic detection of atomic emission radiation at a wavelength characteristic of the element, providing both qualitative elemental speciation and quantitation (24,25). Derivatization with alkyl chloroformates (or alkyl pyrocarbonates) provides an effective route to volatile species for selenoamino acid GC, Se-methylselenocysteine and selenomethionine having been determined in normal and Seenriched plants using GC-AED following ethyl chloroformate derivatization (26).…”

Section: Resultsmentioning

confidence: 99%

Identification and Synthesis of a Novel Selenium−Sulfur Amino Acid Found in Selenized Yeast: Rapid Indirect Detection NMR Methods for Characterizing Low-Level Organoselenium Compounds in Complex Matrices

Block

Glass

Jacobsen

et al. 2004

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

After proteolytic digestion, aqueous extraction, and derivatization with diethyl pyrocarbonate or ethyl chloroformate, HPLC-inductively coupled plasma (ICP)-MS, GC-atomic emission detection (AED), and GC-MS analysis of high-selenium yeast stored at room temperature for more than 10 years showed selenomethionine as the major Se product along with substantial amounts of selenomethionine selenoxide hydrate and the previously unreported selenoamino acid having a Se-S bond, S-(methylseleno)cysteine. The identity of the latter compound was confirmed by synthesis. The natural product was shown to be different from a synthetic sample of the isomeric compound Se-(methylthio)selenocysteine. Selenium-specific NMR spectroscopic methods were developed to directly analyze the aqueous extracts of the hydrolyzed selenized yeast without derivatization or separation. Selenomethionine and S-(methylseleno)cysteine were identified by 77 Se-1 H HMQC-TOCSY experiments.

show abstract

Allium Chemistry: Identification of Selenoamino Acids in Ordinary and Selenium-Enriched Garlic, Onion, and Broccoli Using Gas Chromatography with Atomic Emission Detection

Cited by 151 publications

References 22 publications

Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds

Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds

Production of selenium-enriched milk and dairy products

Identification and Synthesis of a Novel Selenium−Sulfur Amino Acid Found in Selenized Yeast: Rapid Indirect Detection NMR Methods for Characterizing Low-Level Organoselenium Compounds in Complex Matrices

Contact Info

Product

Resources

About