TY - JOUR
T1 - Uptake and specification of selenium in garlic cultivated in soil amended with symbiotic fungi (mycorrhiza) and selenate
AU - Larsen, E.H.
AU - Lobinski, R.
AU - Burger-Meijer, K.
AU - Hansen, M.
AU - Ruzik, R.
AU - Mazurowska, L.
AU - Rasmussen, P.H.
AU - Sloth, J.J.
AU - Scholten, O.E.
AU - Kik, C.
PY - 2006
Y1 - 2006
N2 - The scope of the work was to investigate the influence of selenate fertilisation and the addition of symbiotic fungi (mycorrhiza) to soil on selenium and selenium species concentrations in garlic. The selenium species were extracted from garlic cultivated in experimental plots by proteolytic enzymes, which ensured liberation of selenium species contained in peptides or proteins. Separate extractions using an aqueous solution of enzyme-deactivating hydroxylamine hydrochloride counteracted the possible degradation of labile selenium species by enzymes (such as alliinase) that occur naturally in garlic. The selenium content in garlic, which was analysed by ICP¿MS, showed that addition of mycorrhiza to the natural soil increased the selenium uptake by garlic tenfold to 15 ¿g g¿1 (dry mass). Fertilisation with selenate and addition of mycorrhiza strongly increased the selenium content in garlic to around one part per thousand. The parallel analysis of the sample extracts by cation exchange and reversed-phase HPLC with ICP¿MS detection showed that ¿-glutamyl-Se-methyl-selenocysteine amounted to 2/3, whereas methylselenocysteine, selenomethionine and selenate each amounted to a few percent of the total chromatographed selenium in all garlic samples. Se-allyl-selenocysteine and Se-propyl-selenocysteine, which are selenium analogues of biologically active sulfur-containing amino acids known to occur in garlic, were searched for but not detected in any of the extracts. The amendment of soil by mycorrhiza and/or by selenate increased the content of selenium but not the distribution of detected selenium species in garlic. Finally, the use of two-dimensional HPLC (size exclusion followed by reversed-phase) allowed the structural characterisation of ¿-glutamyl-Se-methyl-selenocysteine and ¿-glutamyl-Se-methyl-selenomethionine in isolated chromatographic fractions by quadrupole time-of-flight mass spectrometry
AB - The scope of the work was to investigate the influence of selenate fertilisation and the addition of symbiotic fungi (mycorrhiza) to soil on selenium and selenium species concentrations in garlic. The selenium species were extracted from garlic cultivated in experimental plots by proteolytic enzymes, which ensured liberation of selenium species contained in peptides or proteins. Separate extractions using an aqueous solution of enzyme-deactivating hydroxylamine hydrochloride counteracted the possible degradation of labile selenium species by enzymes (such as alliinase) that occur naturally in garlic. The selenium content in garlic, which was analysed by ICP¿MS, showed that addition of mycorrhiza to the natural soil increased the selenium uptake by garlic tenfold to 15 ¿g g¿1 (dry mass). Fertilisation with selenate and addition of mycorrhiza strongly increased the selenium content in garlic to around one part per thousand. The parallel analysis of the sample extracts by cation exchange and reversed-phase HPLC with ICP¿MS detection showed that ¿-glutamyl-Se-methyl-selenocysteine amounted to 2/3, whereas methylselenocysteine, selenomethionine and selenate each amounted to a few percent of the total chromatographed selenium in all garlic samples. Se-allyl-selenocysteine and Se-propyl-selenocysteine, which are selenium analogues of biologically active sulfur-containing amino acids known to occur in garlic, were searched for but not detected in any of the extracts. The amendment of soil by mycorrhiza and/or by selenate increased the content of selenium but not the distribution of detected selenium species in garlic. Finally, the use of two-dimensional HPLC (size exclusion followed by reversed-phase) allowed the structural characterisation of ¿-glutamyl-Se-methyl-selenocysteine and ¿-glutamyl-Se-methyl-selenomethionine in isolated chromatographic fractions by quadrupole time-of-flight mass spectrometry
KW - mass-spectrometric detection
KW - mammary-cancer prevention
KW - atomic-emission detection
KW - hplc-icp-ms
KW - allium chemistry
KW - liquid-chromatography
KW - gas-chromatography
KW - selenoamino acids
KW - human health
KW - yeast
U2 - 10.1007/s00216-006-0535-x
DO - 10.1007/s00216-006-0535-x
M3 - Article
SN - 1618-2642
VL - 385
SP - 1098
EP - 1108
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 6
ER -
