Lack of Exposure to Mycobacterium bovis and Mycobacterium avium subsp. paratuberculosis in Chilean Cervids, and Evidence of a New Mycobacterium-Like Sequence.

Screening of serum and fecal samples from huemul (Hippocamelus bisulcus) and pudu (Pudu puda) from southern Chile for Mycobacterium bovis and Mycobacterium avium paratuberculosis (MAP) found all but four samples Mycobacterium-negative. The positive sequences showed only 92-93% similarity with MAP and were from remote Isla Riesco populations.

Molybdenum(VI) dioxo complexes with tridentate phenolate ligands.

A series of new molybdenum(VI) dioxo complexes of the type [MoO(2)ClL(X)] with potentially monoanionic phenolate ligands L(X) (L = 4,6-di-tert-butyl-2-{[(X)methylamino]methyl}-phenolate; L(OMe), where X = 2'-methoxyethyl; L(SEt), where X = 2'-ethylthioethyl; L(NEt2), where X = 2'-diethylaminoethyl; and L(NMe2), where X = 2'-dimethylaminoethyl) have been synthesized as models for molybdoenzymes. All molybdenum complexes were readily accessible by employing the eta(2)-coordinate pyrazolate complex [MoO(2)Cl(eta(2)-t-Bu(2)pz)]. The nitrogen ligand can easily be exchanged by the monoanionic phenolate ligands L(X) in toluene at room temperature, leading to monosubstituted complexes 1-4 as yellow to red powders in good yields. Suitable single crystals for X-ray diffraction analysis of complexes 2 and 3 were obtained from a concentrated benzene solution. Both complexes reveal a six-coordinate molybdenum atom in a distorted octahedral surrounding, with a tridentate fac coordination of the ligand. Additionally, the complexes were characterized by elemental analysis; IR, UV/vis, and NMR spectroscopy; and mass spectrometry. For complexes 1 and 2, only one isomer can be detected in solution, whereas complexes 3 and 4 reveal the formation of two isomers in a 1:1 ratio for 3 and in a 1:3 ratio for 4. Optimized geometries and relative free energies of all possible isomers have been established by DFT calculations, indicating two isomers in solutions of 3 and 4 to be two types of facially coordinated complexes. Furthermore, this is supported by gauge-independent atomic orbital calculations of the (1)H NMR shifts with a high correlation of experimental and calculated shifts for the fac compounds. Oxygen atom transfer reactions of 1 to PMe(3) quickly form monooxo molybdenum compound cis,mer-[MoOCl(2)(PMe(3))(3)].