Adducts characterization

The hw-amine adducts characterized are green, paramagnetic, irans-octahedral species whereas the nature of the mono-amine adducts has been more controversial 143,147,148,152,158) stabihty constant measurements I44,i53,i56,is8) foj. above reactions have shown that for pyridine and primary amines... 

Identification of DNA-Reactive Metabolites Generated in a Target Tissue, Mouse Skin, In Vivo. Our initial studies focused on activation of DMBA in mouse embryo cells in culture because of the ease of isolation of sufficient DNA for adduct characterization. The cells were exposed to DMBA and the isolated DNA enzymatically hydrolyzed to deoxyribonucleosides. DMBA-deoxyribonucleoside adducts were characterized by fluorescence measurements (11,22), by photosensitivity studies (12) and by column chromatography (23,24). These studies provided evidence that the DNA-reactive metabolite generated in these cells is a bay region dihydrodiol epoxide. The enzymatic steps in this activation pathway (Figure 1) involve oxidation of DMBA by mixed function oxidases to a 3,4-epoxide which is converted by epoxide hydrase to a 3,4-dihydro-diol. This is, in turn, oxidized by mixed function oxidases to the dihydrodiol epoxide. 

The (1120) faces, dominant on poly crystalline samples, are characterized by highly shielded fivefold Fe3+ ions (5.43 A apart) and partial homopolar character. The situation is similar to that encountered on prismatic (1120) faces of (y-Cr20, after sintering under severe conditions. When probed with CO, Fe3+ ions exposed on the (1100) surfaces form weak Fe3+ CO adducts, characterized by a very modest shift of the C-0 stretching mode relative to the gas phase value (v = 2164-2165.5 cm A v = 20-22 cm-1). It is thus concluded that the local electric fields associated with Fe3+ ions at the surface of (1100) faces are very weak and similar to those reported for Mg2+ on MgO (001) and Cr3+ on (y-( r202 (1120) surfaces. 

In a similar biochemically oriented vein, several papers were published during 2003 in the journal Chemical Research in Toxicology, representing yet another area of applicability of 3 mm NMR probe capabilities. In the first of these reports, Hankin et al.159 described the results of an investigation into the covalent binding of leukotriene A4 to DNA and RNA. Later in 2003, Blair and co-workers160 reported on the characterization of 2 -deoxycytidine adducts derived from 4-oxo-2-nonenal, a novel lipid peroxidation product. Two of the adducts characterized, Ai and A2, were consistent with substituted ethano-deoxycytidine structures. The third adduct, B, was characterized as a 7-heptanone-etheno-deoxycytidine adduct (78). 

Dihydro derivatives of zirconium(IV) and hafnium(IV), formula M(r/ -CjH5)2H2, react with CO at low temperature to give a carbonyl adduct characterized by a CO... 

Baer, B. R., Rettie, A. E., Henne, K. R. Bioactivation of 4-ipomeanol by CYP4B1 adduct characterization and evidence for an enedial intermediate. Chem. Res. Toxicol. 2005, 18, 855-864. 

Further studies of the reaction of molybdenum and tungsten carbonyl complexes with Lewis acids have been reported and several interesting new adducts characterized. [Mg(py)4][(7r-Cp)Mo(CO)3]2 has been obtained by a metal-exchange reaction from [Hg Mo(7t-Cp)(CO)3 2] in THF, followed by recrystallization from pyridine. X-Ray crystallographic studies have shown the compound to possess the units (67), the dimensions of which suggest that an... 

Tilby, M. J. Lawley, P. D. Farmer, P. B. Alkylation of DNA by melphalan in relation to immunoassay of melphalan DNA adducts characterization of mono-alkylated and cross-linked products from reaction of melphalan with deoxy-GMP and GMP. Chem-Biol. Interact, 73 183-94. 1990. 

R. Subramanyam, A.G. Pinkus, Synthesis of poly(terephthaUc anhydride) by hydrolysis of terephthaloyl chloride triethylamine intermediate adduct characterization of intermediate adduct, J Macromol Sci Chem A22 (1985)23. 

---