Selenium speciation analysis of selenium-enriched Shiitake mushrooms (Lentinula edodes) by HPLC-ESI-MS

From the paper

Abstract

Selenium (Se) is an essential component of critical enzymes and is intricately linked to human health. Shiitake mushrooms (Lentinula edodes) are considered as good dietary supplements for producing Se-enriched foods due to their high protein content and ability to absorb minerals from growth substrates. In this study, the distribution of soluble Se in Se-enriched L. edodes was analyzed by microwave digestion and hydride generation-atomic fluorescence spectrometry (HG-AFS). In order to evaluate the absorption and conversion effect of Se by L. edodes, the Se-containing compounds in selenized L. edodes were quantitatively and qualitatively analyzed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS). It can be shown that L. edodes possessed a good biological transformation ability of organic Se enrichment though the quantitative analysis of three seleno-amino acids, selenocystine (Se-Cys₂), methylselenocysteine (Se-MeSeCys) and selenomethionine (Se-Met), in selenized L. edodes. The structures of three unknown Se-containing compounds were identified by qualitative analysis, the results indicated that the possible structures were selenomethylmethionine (C₆H₁₄NO₂Se), N-Acetyl-selenomethionine (C₇H₁₃NO₃Se) and Se-methyl-5-selenoadenosinese-oxide (C₁₂H₁₈N₅O₃Se). The discovery of these Se compounds filled the research gap and provided a theoretical basis for molecular structure identification and mechanism study of organic Se in Se-enriched L. edodes.