Phylogeny and morphology of Glugea hertwigi from rainbow smelt Osmerus mordax found in Prince Edward Island, Canada.

Infection of rainbow smelt Osmerus mordax with the microsporidian Glugea hertwigi was diagnosed for the first time in Prince Edward Island, Canada. The prevalence of infection was 24%, 45 infected out of 187 examined fish captured in February and March 2009. Both large and small xenomas of G. hertwigi observed within the submucosa of the gastrointestinal tract and along the mesentery of the host contained only mature spores. Advanced and degraded xenomas associated with host reaction were described using light and transmission electron microscopy. The first rDNA sequence of G. hertwigi prepared in the present study completed the set of sequences of Glugea spp. available for comparison. The high level of rDNA sequence identity between Glugea spp. suggests that these may be variants of a single species.

The three-dimensional structural characterization of hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO).

The 1H NMR spectrum and the crystal structure of HCDBCO [(1R,2R,5R,6R,9S,10S)-5,6-dibromo-1,10,11,12,13,13-hexachlorotricyclo[8,2,1,0(2,9)]-tridec-11-ene)] are reported. The measured dihedral angles from the X-ray structure correlate very well with those calculated from the proton-proton coupling constants indicating that the conformations in solution and in the solid state are probably very similar. Attempts at calculating the 3D model structure of HCDBCO only produced a very poor match between the measured dihedral angles between vicinal protons and the observed proton-proton coupling constants from the 1H NMR spectrum. GC/MS analysis with an injector temperature of 250 degrees C produced minor amounts of debrominated HCDBCO. Reducing the temperature to 200 degrees C eliminated this problem.

Theoretical studies of the conformations and 19F NMR spectra of linear and a branched perfluorooctanesulfonamide (PFOSAmide).

Technical perfluorooctanesulfonate (PFOS) and its derivatives, such as perfluorooctanesulfonamide (PFOSA), are not clean compounds but, instead, complex mixtures of linear and branched isomers, and other compounds including sulfonate homologues. Questions have been raised as to whether the linear and the branched isomers behave differently in the environment. However, little is known about the physical properties or the finer details of the structures of the individual branched isomers. This study sought an effective computational method to model the preferred conformations of PFOS derivatives, and the energy differences between them and to determine if these results can be used to explain the temperature dependence of their NMR spectra. Good predictions of the 19F chemical shifts were obtained for some PFOSA-type molecules with a computational approach [B3LYP-GIAO/6-31++G(d,p)//B3LYP/6-31G(d,p)] that is relatively inexpensive. Large 5JFF couplings found in one of the branched isomers could be rationalized on the basis of the relevant F-F distances in the optimized structure. At low temperatures, the splitting observed in the NMR spectrum at C-1 for these sulfonamides can be explained by the existence of the two conformers predicted by the computations.

Characterization of mass-labeled [13C14]-decabromodiphenylethane and its use as a surrogate standard in the analysis of sewage sludge samples.

Very little data is available about the presence of the brominated flame retardant, DBDPE, in the environment. This study reports the characterization of [(13)C(14)]-decabromodiphenylethane and the use of this surrogate standard to positively identify and quantify the presence of DBDPE in sewage sludge samples. The large difference in response factors between BDE-209 and DBDPE predicates the use of [(13)C(14)]-decabromodiphenylethane as a surrogate standard to improve the accuracy when determining the levels of DBDPE in environmental samples.

Biosynthesis of gibberellins in Gibberella fujikuroi. Gibberellin A47.

Two minor radioactive products in cultures of G. fujikuroi strain ACC917 supplemented with labeled gibberellin A4 have been identified as the 2alpha-hydroxy derivative, gibberellin A47, and the hydrate, gibberellin A2. In addition, evidence was obtained by combined gas chromatography--mass spectrometry for the formation of 3-O-acetylgibberellin A1,3-O-acetylgibberellin A3, and gibberellin A20 by the culture. The time course of gibberellin synthesis in defined and complex media, as well as changes in the relative amounts of radioactive gibberellins formed when [4C]gibberellin A4 was added to cultures at different ages, suggest that the composition of the gibberellin mixture produced is determined by the balance between synthesis and decay of key enzymes in the branching pathway.