title: Characterization of binding and bioaccessibility of Cr in Cr-enriched yeast by sequential extraction followed by two-dimensional liquid chromatography with mass spectrometric detection.
abstract: Sequential extraction (water, Driselase, protease XIV) and extraction with simulated gastric and intestinal fluids were proposed to characterize the binding and the bioaccessibility of chromium in two commercial food supplements obtained by incorporation of this element into yeast. Chromium in Cr-enriched yeast was found to be hardly extractable with water, Driselase, or simulated gastric fluid (recoveries of approximately 10-20%), but proteolysis or gastrointestinal fluid digestion released more than half of the chromium present. Fractionation with size-exclusion chromatography with Cr-specific detection by inductively coupled plasma mass spectrometry (ICP MS) allowed the distinction of two fractions: one below approximately 1 kDa and one 1-5 kDa; they contained the entirety of the released Cr with proportions varying as a function of the extracting solution and the origin of sample. When collected and investigated by reversed-phase high-performance liquid chromatography-ICP MS, the low molecular mass fraction was found to release Cr(III), whereas the heavier one showed most of Cr bound in fairly stable hydrophobic complexes. However, an attempt of their identification by electrospray ionization MS/MS and matrix-assisted laser desorption ionization MS was not successful.
authors: Laboratoire de Chimie Analytique Bio-inorganique et Environnement, CNRS UMR 5254, Hélioparc, 2, av. Pr. Angot, 64053, France.
authors: Nattikarn
authors: N
authors: Kaewkhomdee
authors: Sandra
authors: S
authors: Mounicou
authors: Joanna
authors: J
authors: Szpunar
authors: Ryszard
authors: R
authors: Lobinski
authors: Juwadee
authors: J
authors: Shiowatana
mesh_terms: D002850:Chromatography, Gel / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000379:methods; D002857:Chromium / Q000032:analysis* / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D015002:Yeast, Dried / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002857:Chromium