Chelation of UO(2)(2+) by vitamin B6 complex derivatives: synthesis and characterization of [UO2(beta-pyracinide)2(H2O)] and [UO2(Pyr2en)DMSO]Cl2{Pyr2en=N,N'-ethylenebis(pyridoxylideneiminato)}. A useful modeling of assimilation of uranium by living beings.
The vitamin B(6) derivatives 4-pyridoxic acid (anionic) and the Schiff base N,N'-ethylenebis(pyridoxylideneiminato) react with UO(2)(NO(3))(2) * 6H(2)O to give [UO(2)(beta-pyracinide)(2)(H(2)O)] (beta-pyracin=4-pyridoxic acid) and [UO(2)(Pyr(2)en)DMSO]Cl(2)(Pyr(2)en=N,N'-ethylenebis(pyridoxylideneiminato); DMSO=dimethyl sulfoxide). In both compounds the two uranyl oxo ligands set the axis of distorted pentagonal bipyramides. The ability of vitamin B(6) derivatives to react with UO(2)(2+) allowing the chelation of one uranium atom represents a very specific model of assimilation of uranium by living beings. It could also explain the serious damages caused by heavy or radioactive metals like uranium since their complexation "in vivo" by enzymatic systems like pyridoxal phosphate-containing enzymes would lead to a modification of the prosthetic groups of the metalloenzymes with loss of their catalytic activities.
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Davi Fernando
DF
Departamento de Química, Laboratório de Materiais Inorgânicos, Universidade Federal de Santa María, 97105-900 Santa Maria, RS, Brazil.
de Oliveira
Gelson Manzoni
GM
Lang
Ernesto Schulz
ES
D002614:Chelating Agents / Q000737:chemistry; D015392:Chemistry, Inorganic / Q000379:methods; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008962:Models, Theoretical; D017974:Uranium Compounds / Q000737:chemistry* / Q000378:metabolism*; D025101:Vitamin B 6 / Q000737:chemistry* / Q000378:metabolism
D002614:Chelating Agents; D017974:Uranium Compounds; D025101:Vitamin B 6; C047385:uranium oxide