title: Thiamin phosphates in egg yolk granules and plasma of regular and embryonated eggs of hens and in five- and seven-day-old embryos.
abstract: The thiamin (TH), thiamin monophosphate (TMP), thiamin diphosphate (TDP), and thiamin triphosphate (TTP) content was analyzed in yolk plasma and yolk granules of unincubated and incubated chicken eggs and in 5- and 7-day-old chick embryos. Analytes were extracted from samples weighing approximately 1 g, with trichloroacetic acid (0.4 g/L), isolated with solid-phase extraction, and determined with HPLC. Before solid-phase extraction with a C-18 cartridge and a strong anion exchange cartridge, analytes were converted to thiochromes with cyanogen bromide. For HPLC, a C-8 pre-column and a C-8 column connected to a NH(2) column were used with a fluorescence detector. No thiamin phosphates were found in egg yolk plasma or granules in native and embryonated eggs. The TH content in DM was 3,400 +/- 700 ng/g for yolk plasma, 1,500 +/- 140 ng/g for yolk granules of unincubated eggs, and 4,400 +/- 1,100 ng/g for yolk plasma and 2,100 +/- 450 ng/g for yolk granules of 5-d embryonated eggs. In chick embryos, TH as well as thiamin phosphates were found. The mean content in 5-d-old embryos was 1,200 +/- 400 ng of TH and 8,000 +/- 1,000 ng of TDP/g of DM. In 7-d-old embryos, the content of TH was 900 +/- 200 ng, TMP was 400 +/- 200 ng, and TDP was 5,500 +/- 1,300 ng/g of DM. Thiamin triphosphate was not detected, and the minimum detectable limit for T was 0.3 ng/mL, for TMP 0.5 ng/mL, and for TDP 0.9 ng/mL, respectively. Recovery was 71% for TMP and 64% TDP in plasma and 58% TMP and 47% TDP in granules. It was demonstrated that only TH is present in egg yolk fractions in native and embryonated eggs of hens and that thiamin phosphates can be found in 5- and 7-d-old embryos, which indicates that they are synthesized by the chick embryo. According to its assumed unique role in highly specialized tissues, TTP was not found in early embryos.
authors: Center for Food Sciences, Institute for Food Toxicology and Chemical Analytics, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/123, D-30173, Hannover, Germany.
authors: S
authors: S
authors: Bäckermann
authors: C
authors: C
authors: Poel
authors: W
authors: W
authors: Ternes
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D004530:Egg Yolk / Q000737:chemistry*; D005260:Female; D013047:Specific Pathogen-Free Organisms; D013831:Thiamine / Q000032:analysis*; D013833:Thiamine Monophosphate / Q000032:analysis*; D013835:Thiamine Pyrophosphate / Q000032:analysis*; D013838:Thiamine Triphosphate / Q000032:analysis*
chemical_list: D013838:Thiamine Triphosphate; D013833:Thiamine Monophosphate; D013835:Thiamine Pyrophosphate; D013831:Thiamine