Molybdenum Oxygen Transfer Biomimetic Synthesis And Study Of Enzyme Activity End Of The Ligand Field

Molybdenum is an essential trace mineral that plays intimate roles in the global cycles of nitrate, carbon, and sulfur. It takes two forms when participated in the element metabolism, one is as inorganic salt and composed with nutrition, the other is as the cofacter of molybdeumenzy and takes part in many biochemistry reaction. Since last century 50 s the research shows that there is another kind of enzyme containing molybdenum except for nitrogen enzyme, which include xanthenes oxidase, nitrate reductase , sulfite oxidase and aldehyde oxidoreductase et al. Those molybdeumenzy have important influence upon the metabolism of carbohydrate, fat, protein, sulfamino acid, nucleic acid (DNA and RNA), and iron in iron albumen.The active site structure of the molybdenum oxotransferase is likely to change during foster the molybdenumenzyme crystal because of the sensitivity and friability of the protein, which can make the result warp. There is still much to know about the surroundings of the molybdenum center. So the syntheses of the Mo-S (O/N) complexes and the researches of the structure and electron transfer of the molybdenum center can provide useful information for the crystal structure and activities studies of the molybdenumenzyme.1 Three different complexes were synthesized by the reaction of (n-Bu₄N_{4 4}[Mo₈O₂6] with catechol in the mixed solvent of CH₃OH CH₃CN, with NH₂CH₂CH₂NH₂, NH₂CH₂CHNH₂CH₃, and NH₂CH₂CH₂CH₂NH₂ added, and structurally characterized by x-ray diffraction. The crystal structure result shows that the mononuclear anionic unit of the three complexes displayed the same cis-dioxo fashion with pseudo-octahedral [MoO₆] coordination geometry. But the three complexes have different crystal figure, stability and anti-cancer activity. Those complexes show the similar EPR signals with xanthenes oxidase in milk and semblable UV-VIS signals with xanthenes dehydrogenase in chicken liver.2 2,3-dihydroxynaphthalene was chosen to react with Na₂MoO₄ in the mixedsolvent of CH₃OH, CH₃CN, with NH₂CH₂CH₂NH₂, NH₂CH₂CHNH₂CH₃, and NH₂CH₂CH₂CH₂NH₂ added, and two different molybdenum complexes were synthesized. When NH₂CH₂CH₂NH₂ was added to the mixed solvent, one-dimension mononuclear molybdenum complex was synthesized and the Na was also participated in it. The mononuclear molybdenum complex with the same anionic structure as before was synthesized when NH₂CH₂CH₂CH₂NH₂ was added, also when NH₂CH₂CHNH₂CH₃ added nothing was got from the solvent. The two complexes was structurally characterized by x-ray diffraction and researched with UV-VIS, also the NMR studies was taken on the later complex.3 2-hydroxypyrimidine and 2-anminothiophenol were chosen as ligand in the mixed solvent of CH₃OH and dichloromethane, and two compounds were synthesized and the IR studies shows that there are characteristic absorbed peak in about 900cm^-1, which is the character of molybdenum complex with pseudo-octahedral coordination geometry. The o-phenylenediamine was also chosen as N donor ligand to react with Na₂MoO₄ in H₂O and phenazine- 2,3-diamine with nut-brown of o-phenylenediamine dimmer was synthesized at the same time with acid added. Their crystal structures were determined by X-ray diffraction and researched with UV-VIS, IR, and fluorescence spectrophotometer, also the possible mechanism was discussed.