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Full-Text Articles in Physical Sciences and Mathematics

Fragmentation Pathways Of 2,3-Dimethyl-2,3-Dinitrobutane Cations In The Gas Phase, Martin Paine, Benjamin Kirk, Simon Ellis-Steinborner, Stephen J. Blanksby Oct 2010

Fragmentation Pathways Of 2,3-Dimethyl-2,3-Dinitrobutane Cations In The Gas Phase, Martin Paine, Benjamin Kirk, Simon Ellis-Steinborner, Stephen J. Blanksby

Stephen Blanksby

2,3-Dimethyl-2,3-dinitrobutane (DMNB) is an explosive taggant added to plastic explosives during manufacture making them more susceptible to vapour-phase detection systems. In this study, the formation and detection of gas-phase [M+H](+), [M+Li](+), [M+NH4](+) and [M+Na](+) adducts of DMNB was achieved using electrospray ionisation on a triple quadrupole mass spectrometer. The [M+H](+) ion abundance was found to have a strong dependence on ion source temperature, decreasing markedly at source temperatures above 50 degrees C. In contrast, the [M+Na](+) ion demonstrated increasing ion abundance at source temperatures up to 105 degrees C. The relative susceptibility of DMNB adduct ions toward dissociation was investigated …


Synthesis Of Hyacinthacine B-3 And Purported Hyacinthacine B-7, Christopher W.G. Au, Robert J. Nash, Stephen G. Pyne Jan 2010

Synthesis Of Hyacinthacine B-3 And Purported Hyacinthacine B-7, Christopher W.G. Au, Robert J. Nash, Stephen G. Pyne

Faculty of Science - Papers (Archive)

The synthesis of hyacinthacines B-3 and B-7 has confirmed the structure of the former alkaloid and shown that the structure of the latter is incorrect.


Distribution Of Class 1 Integrons With Is26-Mediated Deletions In Their 3'-Conserved Segments In Escherichia Coli Of Human And Animal Origin., Fay E. Dawes, Alexander Kuzevski, Karl A Bettelheim, Michael A Hornitzky, Steven P Djordjevic, Mark J. Walker Jan 2010

Distribution Of Class 1 Integrons With Is26-Mediated Deletions In Their 3'-Conserved Segments In Escherichia Coli Of Human And Animal Origin., Fay E. Dawes, Alexander Kuzevski, Karl A Bettelheim, Michael A Hornitzky, Steven P Djordjevic, Mark J. Walker

Faculty of Science - Papers (Archive)

Class 1 integrons play a role in the emergence of multi-resistant bacteria by facilitating the recruitment of gene cassettes encoding antibiotic resistance genes. 512 E. coli strains sourced from humans (n = 202), animals (n = 304) and the environment (n = 6) were screened for the presence of the intI1 gene. In 31/79 integron positive E. coli strains, the gene cassette regions could not be PCR amplified using standard primers. DNA sequence analysis of 6 serologically diverse strains revealed atypical integrons harboured the dfrA5 cassette gene and only 24 bp of the integron 3'-conserved segment (CS) remained, due to …


Total Synthesis Of Uniflorine A, Casuarine, Australine, 3-Epi-Australine, And 3,7-Di-Epi-Australine From A Common Precursor, Thunwadee Ritthiwigrom, Anthony C. Willis, Stephen G. Pyne Jan 2010

Total Synthesis Of Uniflorine A, Casuarine, Australine, 3-Epi-Australine, And 3,7-Di-Epi-Australine From A Common Precursor, Thunwadee Ritthiwigrom, Anthony C. Willis, Stephen G. Pyne

Faculty of Science - Papers (Archive)

A flexible method for the diastereoselective total synthesis of the pyrrolizidine alkaloids Uniflorine A, casuarine, australine, and 3-epi-australine and the unnatural epimer 3,7-di-epi-australine from a common chiral 2,5-dihydropyrrole precursor is described.