Open Access. Powered by Scholars. Published by Universities.®
Social and Behavioral Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 18 of 18
Full-Text Articles in Social and Behavioral Sciences
Regioselective Synthesis Of Novel E-Edge-[60]Fullerenylmethanodihydropyrroles And 1,2-Dihydromethano[60]Fullerenes, Leila Chaker, Graham E. Ball, James R. Williams, Glenn A. Burley, Bill C. Hawkins, Paul A. Keller, Stephen G. Pyne
Regioselective Synthesis Of Novel E-Edge-[60]Fullerenylmethanodihydropyrroles And 1,2-Dihydromethano[60]Fullerenes, Leila Chaker, Graham E. Ball, James R. Williams, Glenn A. Burley, Bill C. Hawkins, Paul A. Keller, Stephen G. Pyne
Faculty of Science - Papers (Archive)
Treatment of a tethered N-(diphenylmethylene)glycinate-malonate derivative with [60]fullerene under Bingel conditions yielded an e-edge-[60]fullerenylmethanodihydropyrrole adduct in a regioselective manner. The regiochemical outcome was independent of the order of addition of either the N-(diphenylmethylene)glycinate or the malonate moieties. This new bis-adduct was also prepared in 13C enriched form allowing for its unequivocal structural characterization by 2D INADEQUATE NMR experiments. Ring-opening of the dihydropyrrole functionality of the bisadducts under reductive conditions gave exclusively novel dihydromethano[60]fullerene derivatives.
Is Plasminogen Deployed As A Streptococcus Pyogenes Virulence Factor?, Mark J. Walker, Jason D. Mcarthur, F. Mckay, M. Ranson
Is Plasminogen Deployed As A Streptococcus Pyogenes Virulence Factor?, Mark J. Walker, Jason D. Mcarthur, F. Mckay, M. Ranson
Faculty of Science - Papers (Archive)
Streptococcus pyogenes (group A streptococcus) causes human skin and throat infections as well as highly invasive diseases including necrotising fasciitis. Group A streptococcal infections and invasive disease have made a resurgence in developed countries over the last two decades. S. pyogenes utilise multiple pathways for the acquisition and activation of human plasminogen, securing potent proteolytic activity on the bacterial cell surface. Recent experimental evidence using a humanised transgenic mouse model suggests a critical role for human plasminogen in the dissemination of S. pyogenes in vivo.
Tandem Mass Spectrometry Of Deprotonated Iodothyronines, A. M. Couldwell, M. C. Thomas, Todd Mitchell, A. Hulbert, Stephen J. Blanksby
Tandem Mass Spectrometry Of Deprotonated Iodothyronines, A. M. Couldwell, M. C. Thomas, Todd Mitchell, A. Hulbert, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
In order to assist with the development of more selective and sensitive methods for thyroid hormone analysis the [M-H]– anions of the iodothyronines; T4, T3, rT3, (3,5)-T2 and the non-iodinated thyronine (T0) have been generated by negative ion electrospray mass spectrometry. Tandem mass spectra of these ions were recorded on a triple quadrupole mass spectrometer and show a strong analogy with the fragmentation pathways of the parent compound, tyrosine. All iodothyronines also show significant abundances of the iodide anion in their tandem mass spectra, which represents an attractive target for MRM analysis, given that iodothyronines are the only iodine bearing …
A Comparison Of The Gas Phase Acidities Of Phospholipid Headgroups:Experimental And Computational Studies, M. C. Thomas, Todd Mitchell, Stephen J. Blanksby
A Comparison Of The Gas Phase Acidities Of Phospholipid Headgroups:Experimental And Computational Studies, M. C. Thomas, Todd Mitchell, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
Proton-bound dimers consisting of two glycerophospholipids with different headgroups were prepared using negative ion electrospray ionization and dissociated in a triple quadrupole mass spectrometer. Analysis of the tandem mass spectra of the dimers using the kinetic method provides, for the first time, an order of acidity for the phospholipid classes in the gas phase of PE < PA << PG < PS < PI. Hybrid density functional calculations on model phospholipids were used to predict the absolute deprotonation enthalpies of the phospholipid classes from isodesmic proton transfer reactions with phosphoric acid. The computational data largely support the experimental acidity trend, with the exception of the relative acidity ranking of the two most acidic phospholipid species. Possible causes of the discrepancy between experiment and theory are discussed and the experimental trend is recommended. The sequence of gas phase acidities for the phospholipid headgroups is found to; (i) have little correlation with the relative ionization efficiencies of the phospholipid classes observed in the negative ion electrospray process, and (ii) correlate well with fragmentation trends observed upon collisional activation of phospholipid [M-H]– anions.
Structural Re-Assignment Of The Mono- And Bis-Addition Products From The Addition Reactions Of N-(Diphenylmethylene)Glycinate Esters To [60]Fullerene Under Bingel Conditions, Graham E Ball, Glenn Ashley Burley, Leila Chaker, William Hawkins, James Williams, Paul A. Keller, Stephen G. Pyne
Structural Re-Assignment Of The Mono- And Bis-Addition Products From The Addition Reactions Of N-(Diphenylmethylene)Glycinate Esters To [60]Fullerene Under Bingel Conditions, Graham E Ball, Glenn Ashley Burley, Leila Chaker, William Hawkins, James Williams, Paul A. Keller, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The addition of N-(diphenylmethylene)glycinate esters (Ph2C=NCH2CO2R) to [60]fullerene under Bingel conditions gives [60]fullerenyldihydropyrroles and not methano[60]fullerenyl iminoesters [C60C(CO2R)(N=CPh2)] as previously reported. Unequivocal evidence for the structure of C60C(CO2Et)(N=CPh2) was provided by INADEQUATE NMR studies on 13C enriched material. New mechanistic details are proposed to account for the formation of [60]fullerenyldihydropyrroles and their reductive ring-opening reactions.
Confirmation Of The Structure Of Oxystemokerrin By Single Crystal X-Ray Structural Analysis And A Proposed Biosynthesis, Pitchaya Mungkornasawakul, Hayden Matthews, Alison T. Ung, Stephen G. Pyne, Araya Jatisatienr, Wilford Lie, Brian W. Skelton, Allan H. White
Confirmation Of The Structure Of Oxystemokerrin By Single Crystal X-Ray Structural Analysis And A Proposed Biosynthesis, Pitchaya Mungkornasawakul, Hayden Matthews, Alison T. Ung, Stephen G. Pyne, Araya Jatisatienr, Wilford Lie, Brian W. Skelton, Allan H. White
Faculty of Science - Papers (Archive)
The crystal structure of the pentacyclic Stemona alkaloid oxystemokerrin (2), isolated from the roots of Stemona kerrii, is reported, confirming the structure proposed for this compound in a contemporaneous spectroscopic study. This compound is a diastereomer of stemocurtisinol (3), whose structure we have recently reported from S. curtisii, also confirmed by a single-crystal X-ray study. These alkaloids have opposite configurations at C-4 and C-19. A possible biosynthetic pathway for the biosynthesis of 2 and 3 is proposed.
Phytochemical Studies On Stemona Plants: Isolation Of Stemofoline Alkaloids, Thanapat Sastraruji, Araya Jatisatienr, Stephen G. Pyne, Alison T. Ung, Wilford Lie, Morwenna C. Williams
Phytochemical Studies On Stemona Plants: Isolation Of Stemofoline Alkaloids, Thanapat Sastraruji, Araya Jatisatienr, Stephen G. Pyne, Alison T. Ung, Wilford Lie, Morwenna C. Williams
Faculty of Science - Papers (Archive)
Six new stemofoline alkaloids, (2‘R)-hydroxystemofoline (5), (3‘R)-stemofolenol (6), (3‘S)-stemofolenol (7), 1‘,2‘-didehydrostemofoline-N-oxide (8), the first C19 stemofoline alkaloid, methylstemofoline (9), and the first glycosidated Stemona alkaloid, stemofolinoside (10), and three known alkaloids, (2‘S)-hydroxystemofoline (2), (11Z)-1‘,2‘-didehydrostemofoline (3), and (11E)-1‘,2‘-didehydrostemofoline (4), have been isolated from a root extract of an unidentified Stemona species. The structure and relative configuration of these new alkaloids have been determined by spectral data interpretation and …
Factors Affecting Metal Releases From Contaminated Marine Sediments, Dianne F. Jolley, Clare A. Atkinson, Stuart L. Simpson
Factors Affecting Metal Releases From Contaminated Marine Sediments, Dianne F. Jolley, Clare A. Atkinson, Stuart L. Simpson
Faculty of Science - Papers (Archive)
In aquatic environments, the depth of oxygen penetration into sediment depends on sediment texture, porosity, permeability and the extent of biological (e.g., bioturbation) and physical (e.g., wave action) processes. Below the oxygen penetration depth (generally 10 mm) anoxic conditions prevail and bacteria use other oxidants such as iron and manganese oxides and sulfate to breakdown organic matter. The bacteria-catalysed reduction of sulfate releases hydrogen sulfide according to Equation 1. The release of H2S into the pore waters SO42- + bacteria → H2S (Equation 1).
Purification, Crystallization And Preliminary Crystallographic Analysis Of Dehiva, A Dehalogenase From Burkholderia Cepacia Mba4, Jason Schmidberger, Aaron Oakley, Jimmy Tsang, Matthew Wilce
Purification, Crystallization And Preliminary Crystallographic Analysis Of Dehiva, A Dehalogenase From Burkholderia Cepacia Mba4, Jason Schmidberger, Aaron Oakley, Jimmy Tsang, Matthew Wilce
Faculty of Science - Papers (Archive)
No abstract provided.
Fractionation Of Sedimentary Arsenic From Port Kembla Harbour, Nsw, Australia, Glennys A. O'Brien, William E. Price, Bryan E. Chenhall, Muhammad Damris
Fractionation Of Sedimentary Arsenic From Port Kembla Harbour, Nsw, Australia, Glennys A. O'Brien, William E. Price, Bryan E. Chenhall, Muhammad Damris
Faculty of Science - Papers (Archive)
The binding of arsenic in sediments of the heavily industrialised Port Kembla Harbour, NSW, Australia, has been investigated. Both dredge and core samples have been used to develop a sieving/sequential extraction (SE) procedure. Dredge samples included oxic surficial and deeper anoxic sediment. The main core sample analysed was 18 cm deep, sliced at 2 cm intervals. Sediment was sieved to three size ranges (250 microm) and each of these was then subjected to a four step SE, sequentially solubilizing arsenic as ion exchangeable, 1 M HCl soluble, NH(2)OH.HCl soluble, and strong oxidising acid soluble. Concentrations of 50-500 mg As kg(-1) …
Autopolymerization Of Pyrrole In The Presence Of A Host/Guest Calixarene, David A. Reece, Jennifer M. Pringle, Stephen F. Ralph, Gordon G. Wallace
Autopolymerization Of Pyrrole In The Presence Of A Host/Guest Calixarene, David A. Reece, Jennifer M. Pringle, Stephen F. Ralph, Gordon G. Wallace
Faculty of Science - Papers (Archive)
Aqueous solutions containing pyrrole and calix-6-arenehexasulfonic acid were found to undergo polymerization in the absence of either a chemical oxidant or electrochemical oxidation. The product was an unstable colloidal suspension consisting of spherical polypyrrole particles measuring ≥500 nm in diameter. Conductivity measurements showed the material to be insulating, while cyclic voltammetry studies demonstrated that it was electroactive. Infrared spectroscopy and microanalysis confirmed that the polypyrrole produced was doped with calix-6-arenehexasulfonic acid. When the reaction was repeated using solutions containing stabilizing agents, stable colloidal dispersions were obtained. These were shown by both particle size analysis and transmission electron microscopy to contain …
A Convenient And Efficient Synthesis Of (S)-Lysine And (S)-Arginine Homologues Via Olefin Cross-Metathesis, Timothy P. Boyle, John B. Bremner, Jonathan A. Coates, Paul A. Keller, Stephen G. Pyne
A Convenient And Efficient Synthesis Of (S)-Lysine And (S)-Arginine Homologues Via Olefin Cross-Metathesis, Timothy P. Boyle, John B. Bremner, Jonathan A. Coates, Paul A. Keller, Stephen G. Pyne
Faculty of Science - Papers (Archive)
A convenient five step synthesis of (S)-homolysine, incorporating a key olefin cross-metathesis step in the chain extension methodology, has been developed, together with a six step related synthesis of a new homologue of arginine, (S)-bishomoarginine.
The Epididymal Soluble Prion Protein Forms A High-Molecular-Mass Complex In Association With Hydrophobic Proteins, Heath W. Ecroyd, Maya Belghazi, Jean-Louis Dacheux, Jean-Luc Gatti
The Epididymal Soluble Prion Protein Forms A High-Molecular-Mass Complex In Association With Hydrophobic Proteins, Heath W. Ecroyd, Maya Belghazi, Jean-Louis Dacheux, Jean-Luc Gatti
Faculty of Science - Papers (Archive)
We have shown previously that a 'soluble' form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993-1001]. Attempts to purify this 'soluble' PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), beta-mannosidase and beta-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and …
Enzyme Activity And Flexibility At Very Low Hydration, V Kurkal, R M. Daniel, John L. Finney, Moeava Tehei, R V. Dunn, Jeremy C. Smith
Enzyme Activity And Flexibility At Very Low Hydration, V Kurkal, R M. Daniel, John L. Finney, Moeava Tehei, R V. Dunn, Jeremy C. Smith
Faculty of Science, Medicine and Health - Papers: part A
Recent measurements have demonstrated enzyme activity at hydrations as low as 3%. This raises the question of whether hydration-induced enzyme flexibility is important for activity. Here, to address this, picosecond dynamic neutron scattering experiments are performed on pig liver esterase powders at 0%, 3%, 12%, and 50% hydration by weight and at temperatures ranging from 120 to 300 K. At all temperatures and hydrations, significant quasielastic scattering intensity is found in the protein, indicating the presence of anharmonic, diffusive motion. As the hydration increases, a temperature-dependent dynamical transition appears and strengthens involving additional diffusive motion. The implication of these results …
Replication Termination In Escherichia Coli: Structure And Anti-Helicase Activity Of The Tus-Ter Complex, Cameron Neylon, Andrew V. Kralicek, Thomas M. Hill, Nicholas E. Dixon
Replication Termination In Escherichia Coli: Structure And Anti-Helicase Activity Of The Tus-Ter Complex, Cameron Neylon, Andrew V. Kralicek, Thomas M. Hill, Nicholas E. Dixon
Faculty of Science, Medicine and Health - Papers: part A
The arrest of DNA replication in Escherichia coli is triggered by the encounter of a replisome with a Tus protein-Ter DNA complex. A replication fork can pass through a Tus-Ter complex when traveling in one direction but not the other, and the chromosomal Ter sites are oriented so replication forks can enter, but not exit, the terminus region. The Tus-Ter complex acts by blocking the action of the replicative DnaB helicase, but details of the mechanism are uncertain. One proposed mechanism involves a specific interaction between Tus-Ter and the helicase that prevents further DNA unwinding, while …
Toxicity, Biotransformation, And Mode Of Action Of Arsenic In Two Freshwater Microalgae (Chlorella Sp. And Monoraphidium Arcuatum), Jacqueline L. Levy, Jennifer L. Stauber, Merrin S. Adams, William A. Maher, Jason K. Kirby, Dianne F. Jolley
Toxicity, Biotransformation, And Mode Of Action Of Arsenic In Two Freshwater Microalgae (Chlorella Sp. And Monoraphidium Arcuatum), Jacqueline L. Levy, Jennifer L. Stauber, Merrin S. Adams, William A. Maher, Jason K. Kirby, Dianne F. Jolley
Faculty of Science - Papers (Archive)
The toxicity of As(V) and As(III) to two axenic tropical 15 freshwater microalgae, Chlorella sp. and Monoraphidium arcuatum, was determined using 72-h growth rate inhibition bioassays. Both organisms were tolerant to As(III) (72-h IC50, concentration to cause 50% inhibition of growth, of 25 and 15 mg As(III)/L, respectively). Chlorella sp. was also tolerant to As(V) with no effect on growth rate over 72 h at concentrations up to 0.8 mg/L (72-h IC50 of 25 mg As(V)/L). M. arcuatum was more sensitive to As(V) (72-h IC50 of 0.25 mg As(V)/L). An increase in phosphate in the growth medium (0.15 to 1.5 …
Synthesis Of 2-Azaspiro[4.4]Nonan-1-Ones Via Phosphine-Catalysed [3+2]-Cycloadditions, Sarah Yong, Morwenna C. Williams, Stephen G. Pyne, Alison T. Ung, Brian W. Skelton, Allan H. White, P. Turner
Synthesis Of 2-Azaspiro[4.4]Nonan-1-Ones Via Phosphine-Catalysed [3+2]-Cycloadditions, Sarah Yong, Morwenna C. Williams, Stephen G. Pyne, Alison T. Ung, Brian W. Skelton, Allan H. White, P. Turner
Faculty of Science - Papers (Archive)
The phosphine-catalysed [3+2]-cycloaddition of the 2-methylene γ-lactams 4 and 5 and the acrylate 6 with the ylides derived from the ethyl ester, the amide or the chiral camphor sultam derivative of 2-butynoic acid (7a-c) give directly, or indirectly after reductive cyclization, spiro-heterocyclic products. The acid 32 underwent Curtius rearrangement and then acid hydrolysis to give two novel spiro-cyclic ketones, 41 and 42.
Synthesis Of Carbocyclic Hydantocidins Via Regioselective And Diastereoselective Phosphine-Catalyzed [3+2]-Cycloadditions To 5-Methylenehydantoins, Tien Quoc Pham, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Synthesis Of Carbocyclic Hydantocidins Via Regioselective And Diastereoselective Phosphine-Catalyzed [3+2]-Cycloadditions To 5-Methylenehydantoins, Tien Quoc Pham, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Faculty of Science - Papers (Archive)
The phosphine-catalysed [3+2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c and 6d gave spiro-heterocyclic products with reverse regioselectivities. The N,N-dibenzylprotected cycloadduct has been converted to carbocyclic hydantocidin and 6,7-diepi-carbocyclic hydantocidin.