Bio-fortification and isotopic labelling of Se metabolites in onions and carrots following foliar application of Se and ⁷⁷Se

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• 作者：Emese Ká ; polna^a ; Kristian H. Laursen^b ; Sø ; ren Husted^b ; Erik H. Larsen^a ; ^{Ehlar@food.dtu.dk}
• 关键词：Foliar application ; Onion ; Carrot ; Methylselenocysteine ; Intrinsic 77Se labelling ; HPLC&ndash ; ESI-MS/MS
• 刊名：Food Chemistry
• 出版年：2012
• 期刊代码：48_03088146
• 类别：abs
• 出版时间：1 August, 2012
• 卷：133
• 期：3
• 页码：650-657
• 文件大小：319 K

摘要

The aims were to bio-fortify onions by foliar application of selenium (Se) and to intrinsically label bioactive Se-metabolites in onion and carrot by enriched, stable ⁷⁷Se for use in human physiological studies. Onion bulbs and leaves were enriched in Se by repeated foliar spraying of 10 or 100 渭g Se ml^鈭? solutions of sodium selenite (Se(IV)) or sodium selenate (Se(VI)). ICP-MS analysis of onion leaves and bulbs showed that the Se concentration was enhanced by up to a factor of approximately 50 and 200 in bulbs and leaves, respectively. HPLC-ICP-MS analysis of proteolytic plant extracts showed that foliar application of Se(IV) gave rise to bio-synthesis of a higher fraction of the desired organic Se species and was better tolerated by the plants than Se(VI). Based on these findings onions and carrots were bio-fortified by foliar application of a solution of ⁷⁷Se(IV) that was enriched to 99.7%as ⁷⁷Se. The ⁷⁷Se- labelled metabolites in onions were predominantly 纬-glutamyl-⁷⁷Se-selenomethyl-selenocysteine (纬-glu-Me⁷⁷SeCys), ⁷⁷Se-methylselenocysteine (Me⁷⁷SeCys) and ⁷⁷Se-selenomethionine (⁷⁷SeMet). Furthermore, we report here for the first time the finding in carrots of the bioactive Me⁷⁷SeCys, the identity of which was verified by HPLC-ESI-MS/MS.