Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 30 of 30
Full-Text Articles in Life Sciences
High-Yield Cell-Free Protein Synthesis For Site-Specific Incorporation Of Unnatural Amino Acids At Two Sites, Kiyoshi Ozawa, Karin V. Loscha, Kekini V. Kuppan, Choy Theng Loh, Nicholas E. Dixon, Gottfried Otting
High-Yield Cell-Free Protein Synthesis For Site-Specific Incorporation Of Unnatural Amino Acids At Two Sites, Kiyoshi Ozawa, Karin V. Loscha, Kekini V. Kuppan, Choy Theng Loh, Nicholas E. Dixon, Gottfried Otting
Faculty of Science - Papers (Archive)
Using aminoacyl-tRNA synthetase/suppressor tRNA pairs derived from Methanocaldococcus jannaschii, an Escherichia coli cell-free protein production system affords proteins with site-specifically incorporated unnatural amino acids (UAAs) in high yields through the use of optimized amber suppressor tRNACUA opt and optimization of reagent concentrations. The efficiency of the cell-free system allows the incorporation of trifluoromethyl-phenylalanine using a polyspecific synthetase evolved previously for p-cyanophenylalanine, and the incorporation of UAAs at two different sites of the same protein without any re-engineering of the E. coli cells used to make the cell-free extract.
Synthesis And Anti-Leukaemic Activity Of Pyrrolo[3,2,1-Hi]Indole-1,2- Diones, Pyrrolo[3,2,1-Ij]Quinoline-1,2-Diones And Other Polycyclic Isatin Derivatives, Lidia Matesic, Julie M. Locke, Kara Vine, Marie Ranson, John B. Bremner, Danielle Skropeta
Synthesis And Anti-Leukaemic Activity Of Pyrrolo[3,2,1-Hi]Indole-1,2- Diones, Pyrrolo[3,2,1-Ij]Quinoline-1,2-Diones And Other Polycyclic Isatin Derivatives, Lidia Matesic, Julie M. Locke, Kara Vine, Marie Ranson, John B. Bremner, Danielle Skropeta
Faculty of Science - Papers (Archive)
To further expand the structure–cytotoxic activity relationships of isatin derivatives and to reduce flexibility in substituent groups at nitrogen, 20 analogues incorporating a ring system between the N1 and C7 atoms of isatin were prepared using a variety of synthetic strategies. This yielded pyrroloindole-, pyrroloquinoline-, pyrroloacridine-, pyrrolophenanthridine- and benzopyrrolophenanthridine-based systems with embedded isatin moieties, the latter possessing a novel carbon skeleton. These compounds were subsequently assessed for their in vitro cytotoxicity against human U937 lymphoma cells, with the brominated pyrroloacridine dione 27 showing the most promising activity (IC50 3.01 μM) after 24 h.
Synthesis, Properties And Water Permeability Of Swnt Buckypapers, L J. Sweetman, L Nghiem, I Chironi, G Triani, Marc In Het Panhuis, St F. Ralph
Synthesis, Properties And Water Permeability Of Swnt Buckypapers, L J. Sweetman, L Nghiem, I Chironi, G Triani, Marc In Het Panhuis, St F. Ralph
Faculty of Science - Papers (Archive)
The ability of macrocyclic ligands to facilitate formation of dispersions of single-walled carbon nanotubes (SWNTs) was investigated using a combination of absorption spectrophotometry and optical microscopy. Vacuum filtration of aqueous dispersions containing SWNTs and various macrocyclic ligands (derivatised porphyrin, phthalocyanine, cyclodextrin and calixarene) afforded self-supporting membranes known as buckypapers. Microanalytical data and energy dispersive X-ray spectra were obtained for these buckypapers and provided evidence for retention of the macrocyclic ligands within the structure of the membranes. The electrical conductivities of the membranes varied between 30 ± 20 and 220 ± 60 S cm−1, while contact angle analysis revealed they all …
Preeclampsia Is Associated With Compromised Maternal Synthesis Of Long-Chain Polyunsaturated Fatty Acids, Leading To Offspring Deficiency, Vanessa A. Mackay, Shahzya S. Huda, Frances M. Stewart, Kahmeng Tham, Louise A. Mckenna, Iain Martin, Fiona Jordan, E Ann Brown, Leanne Hodson, Ian A. Greer, Barbara J. Meyer, Dilys J. Freeman
Preeclampsia Is Associated With Compromised Maternal Synthesis Of Long-Chain Polyunsaturated Fatty Acids, Leading To Offspring Deficiency, Vanessa A. Mackay, Shahzya S. Huda, Frances M. Stewart, Kahmeng Tham, Louise A. Mckenna, Iain Martin, Fiona Jordan, E Ann Brown, Leanne Hodson, Ian A. Greer, Barbara J. Meyer, Dilys J. Freeman
Faculty of Health and Behavioural Sciences - Papers (Archive)
Obesity and excessive lipolysis are implicated in preeclampsia (PE). Intrauterine growth restriction is associated with low maternal body mass index and decreased lipolysis. Our aim was to assess how maternal and offspring fatty acid metabolism is altered in mothers in the third trimester of pregnancy with PE (n=62) or intrauterine growth restriction (n=23) compared with healthy pregnancies (n=164). Markers of lipid metabolism and erythrocyte fatty acid concentrations were measured. Maternal adipose tissue fatty acid composition and mRNA expression of adipose tissue fatty acid–metabolizing enzymes and placental fatty acid transporters were compared. Mothers with PE had higher plasma triglyceride (21%, P<0.001) and nonesterified fatty acid (50%, P<0.001) concentrations than controls. Concentrations of major n−6 and n−3 long-chain polyunsaturated fatty acids in erythrocytes were 23% to 60% lower (all P<0.005) in PE and intrauterine growth restriction mothers and offspring compared with controls. Subcutaneous adipose tissue −5 and −6 desaturase and very long-chain fatty acid elongase mRNA expression was lower in PE than controls (respectively, mean [SD] control 3.38 [2.96] versus PE 1.83 [1.91], P=0.030; 3.33 [2.25] versus 1.03 [0.96], P<0.001; 0.40 [0.81] versus 0.00 [0.00], P=0.038 expression relative to control gene [square root]). Low maternal and fetal long-chain polyunsaturated fatty acid concentrations in PE may be the result of decreased maternal synthesis.
The Synthesis, Structures And Reactions Of Zinc And Cobalt Metal-Organic Frameworks Incorporating An Alkyne-Based Dicarboxylate Linker, Andrew D. Burrows, L C. Fisher, David M. Hodgson, Mary F. Mahon, Naomi Cessford, Tina Duren, Christopher Richardson, S P. Rigby
The Synthesis, Structures And Reactions Of Zinc And Cobalt Metal-Organic Frameworks Incorporating An Alkyne-Based Dicarboxylate Linker, Andrew D. Burrows, L C. Fisher, David M. Hodgson, Mary F. Mahon, Naomi Cessford, Tina Duren, Christopher Richardson, S P. Rigby
Faculty of Science - Papers (Archive)
The reaction of zinc(II) nitrate and 4,4′-ethynylenedibenzoic acid (H2edb) in DMF at 80 °C gave the metal–organic framework material [Zn4O(edb)3(H2O)2]·6DMF 1 in which edb ligands connect Zn4O centres into a doubly-interpenetrated cubic network with a similar topology to observed with other linear dicarboxylates in the IRMOF series. Analysis of the nitrogen isotherm revealed the material to have a BET surface area of 1088 m2 g−1, which is approximately one-third of the value calculated from GCMC simulations, suggesting incomplete activation or pore blocking in the activated …
Synthesis Of 3-Halo-2,5-Disubstituted Furans Via Cux Mediated Cyclization-Halogenation Reactions, Arife Yazici, Stephen G. Pyne
Synthesis Of 3-Halo-2,5-Disubstituted Furans Via Cux Mediated Cyclization-Halogenation Reactions, Arife Yazici, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The Cu(I) halide (X = I, Br, Cl) mediated reactions of Cbz-protected cis-2-phenylethenyl-3-hydroxypyrrolidine gave novel 3-halo-2,5-trisubstituted furans in good yields, via a cyclization-halogenation, ring-opening reaction sequence. In contrast, the reactions with CuCN gave mainly the corresponding 3-cyanofuro[3,2-b]pyrrole formed from a cyclization-cyanation reaction.
Synthesis And Structural Characterization Of 1-[2-(5-Nitro-1h-Indol-2-Yl)Phenyl]Methylpyridinium Chloride, John B. Bremner, Siritron Samosorn, Brian W. Skelton, Allan White
Synthesis And Structural Characterization Of 1-[2-(5-Nitro-1h-Indol-2-Yl)Phenyl]Methylpyridinium Chloride, John B. Bremner, Siritron Samosorn, Brian W. Skelton, Allan White
Faculty of Science - Papers (Archive)
In the course of studies on hybrid antibacterials incorporating 2-aryl-5-nitro-1Hindolemoieties as potential bacterial NorA efflux pump inhibitors, the compound 1-[2-(5-nitro-1H-indol-2-yl)phenyl]methylpyridinium chloride (2) was synthesized and structurallycharacterized. This pyridinium chloride salt crystallized in the monoclinic space groupP21/c with the following unit cell dimensions: a 10.274(3) A, b 13.101(4) A, c 13.439(4)A, B 107.702(7)deg, V 1723.2(9) A3, Z (f.u.) = 4; R1 = 0.048, and wR2 = 0.13. Of interest inthe single crystal X-ray structure is the (intramolecular) disposition of the pyridinium planeover the indole heterocyclic residue [interplanar dihedral angle 17.91(4)deg].
Synthesis And Preliminary Evaluation Of Amiloride Analogs As Inhibitors Of The Urokinase-Type Plasminogen Activator (Upa), Hayden Matthews, Marie Ranson, Joel Tyndall, Michael J. Kelso
Synthesis And Preliminary Evaluation Of Amiloride Analogs As Inhibitors Of The Urokinase-Type Plasminogen Activator (Upa), Hayden Matthews, Marie Ranson, Joel Tyndall, Michael J. Kelso
Faculty of Science - Papers (Archive)
A known side-activity of the oral potassium-sparing diuretic drug amiloride is inhibition of the enzyme urokinase-type plasminogen activator (uPA, Ki = 7 mu M), a promising anticancer target. Several studies have demonstrated significant antitumor/metastasis properties for amiloride in animal cancer models and it would appear that these arise, at least in part, through inhibition of uPA. Selective optimization of amiloride’s structure for more potent inhibition of uPA and loss of diuretic effects would thus appear as an attractive strategy towards novel anticancer agents. The following report is a preliminary structure-activity exploration of amiloride analogs as inhibitors of uPA. A …
Stereoselective Synthesis Of Two New Trihydroxylated Pyrrolidines Using A Meyer-Schuster Rearrangement, Nalivela K. Swamy, Stephen G. Pyne
Stereoselective Synthesis Of Two New Trihydroxylated Pyrrolidines Using A Meyer-Schuster Rearrangement, Nalivela K. Swamy, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The synthesis of two new trihydroxylated pyrrolidines, in a highly diastereoselective manner, has been developed using the Meyer-Schuster rearrangement as a key step. C 2011 Taylor & Francis Group, LLC.
Synthesis Of Novel Sugar Diamino Acids, M Thillakan, A Katsifis, D Skropeta
Synthesis Of Novel Sugar Diamino Acids, M Thillakan, A Katsifis, D Skropeta
Faculty of Science - Papers (Archive)
Sugar amino acids (SAAs) are found in nature as good construction elements for the preparation of peptide mimetics and oiigosaccharides in drug design and development. The synthesis of SAAs is readily accomplished in few steps and more than 40 SAAs have been synthesised to date.2 Sugar amino acids with an additional amino group, the sugar diamino acid (SDAs) would represent a useful expansion to the library of SAAs available because one of the amino group and carboxylic acid is available for peptide coupling and the another amino/azide group allow to do further derivatisation via peptide or click chemistry such as …
Synthesis And Characterization Of Cobalt-Doped Ws2 Nanorods For Lithium Battery Applications, Zaiping Guo, Chuanqi Feng, Guodong Du, Shiquan Wang, L Li, Xueya Jiang, Guohua Li, Seunjoo Kim
Synthesis And Characterization Of Cobalt-Doped Ws2 Nanorods For Lithium Battery Applications, Zaiping Guo, Chuanqi Feng, Guodong Du, Shiquan Wang, L Li, Xueya Jiang, Guohua Li, Seunjoo Kim
Faculty of Health and Behavioural Sciences - Papers (Archive)
No abstract provided.
Synthesis Of Hyacinthacine B-3 And Purported Hyacinthacine B-7, Christopher W.G. Au, Robert J. Nash, Stephen G. Pyne
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.
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
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.
Myriocin-Mediated Up-Regulation Of Hepatocyte Apoa-I Synthesis Is Associated With Erk Inhibition, Elias N. Glaros, Woojin Scott Kim, Brett Garner
Myriocin-Mediated Up-Regulation Of Hepatocyte Apoa-I Synthesis Is Associated With Erk Inhibition, Elias N. Glaros, Woojin Scott Kim, Brett Garner
Faculty of Science - Papers (Archive)
Sphingolipids including sphingomyelin have been implicated as potential atherogenic lipids. Studies in apoE (apolipoprotein E)-null mice have revealed that the serine palmitoyltransferase inhibitor myriocin reduces plasma levels of sphingomyelin, ceramide, sphingosine-I-phosphate and glycosphingolipids and that this is associated with potent inhibition of atherosclerosis. Interestingly, hepatic apoA-I (apolipoprotein A-I) synthesis and plasma HDL (high-density lipoprotein)cholesterol levels were also increased in apoE-null mice treated with myriocin. Since myriocin is a known inhibitor of ERK (extracellular-signal-related kinase) phosphorylation, we assessed the possibility that myriocin may be acting to increase hepatic apoA-I production via this pathway. To address this, HepG2 cells and primary mouse …
Synthesis Of Reaction-Ready 6,6 '-Biindole And 6,6 '-Biisatin Via Palladium(Ii)-Catalysed Intramolecular C-H Functionalisation, Allan B. Gamble, Paul A. Keller
Synthesis Of Reaction-Ready 6,6 '-Biindole And 6,6 '-Biisatin Via Palladium(Ii)-Catalysed Intramolecular C-H Functionalisation, Allan B. Gamble, Paul A. Keller
Faculty of Science - Papers (Archive)
The first synthesis of a 6,6'-biindole and 6,6'-biisatin scaffold is reported with the penultimate step being the formation of the di-heterocyclic ring by Pd(II)-catalysed intramolecular C-H functionalisation and Sandmeyer cyclisation, respectively.
Synthesis And Applications Of Covalent Protein-Dna Conjugates, Patrick M. Schaeffer, Nicholas E. Dixon
Synthesis And Applications Of Covalent Protein-Dna Conjugates, Patrick M. Schaeffer, Nicholas E. Dixon
Faculty of Science - Papers (Archive)
Synthetic protein-DNA conjugates are valuable tools with applications in fields including nanobiotechnology, bioanalytical chemistry, and molecular diagnostics, and various synthetic methods for their production have been developed during the past three decades. The present article reviews current methodologies for the synthesis of covalent protein-DNA conjugates with particular focus on the regiospecificity and stoichiometry of these reactions.
Glutarate And N-Acetyl-L-Glutamate Buffers For Cell-Free Synthesis Of Selectively 15n-Labelled Proteins, X Jia, Kiyoshi Ozawa, K Loscha, G Otting
Glutarate And N-Acetyl-L-Glutamate Buffers For Cell-Free Synthesis Of Selectively 15n-Labelled Proteins, X Jia, Kiyoshi Ozawa, K Loscha, G Otting
Faculty of Science - Papers (Archive)
Cell-free protein synthesis provides rapid and economical access to selectively 15N-labelled proteins, greatly facilitating the assignment of 15N-HSQC spectra. While the best yields are usually obtained with buffers containing high concentrations of potassium L-glutamate, preparation of selectively 15N-Glu labelled samples requires non-standard conditions. Among many compounds tested to replace the L-Glu buffer, potassium N-acetyl-L-glutamate and potassium glutarate were found to perform best, delivering high yields for all proteins tested, with preserved selectivity of 15N-Glu labelling. Assessment of amino-transferase activity by combinatorial 15N-labelling revealed that glutarate and N-acetyl-L-glutamate suppress the transfer of the 15N-alpha-amino groups between amino acids less well than …
Eoarchaean Crustal Growth In West Greenland (Itsaq Gneiss Complex) And In Northeastern China (Anshan Area): Review And Synthesis, Allen P. Nutman, Vickie C. Bennett, Clark R L Friend, Frances Jenner, Yusheng Wan, Dunyi Liu
Eoarchaean Crustal Growth In West Greenland (Itsaq Gneiss Complex) And In Northeastern China (Anshan Area): Review And Synthesis, Allen P. Nutman, Vickie C. Bennett, Clark R L Friend, Frances Jenner, Yusheng Wan, Dunyi Liu
Faculty of Science - Papers (Archive)
Eoarchaean crust in West Greenland (the Itsaq Gneiss Complex, 3870-3600 Ma) is >80% by volume orthogneisses derived from plutonic tonalite-trondhjemite-granodiorite (TTG) suites,3850, c. 3810 and c. 3710 Mahave some compositional similarities to modern island arc basalts (IAB), suggesting their origin by hydrous fluxing of a suprasubduction-zone upper mantle wedge. Most of the Eoarchaean tonalites match in composition high-silica, low-magnesian adakites, whose petrogenesis is dominated by partial melting of garnetiferous mafic rocks at high pressure. However, associated with the tonalites are volumetrically minor more magnesian quartz diorites, whose genesis probably involved melting of depleted mantle to which some slab-derived component had …
Synthesis And Ph-Responsive Properties Of Pseudo-Peptide Containing Hydrophobic Amino Acid Grafts, Rongjun Chen, Mark E. Eccleston, Zhilian Yue, Nighel K. H Slater
Synthesis And Ph-Responsive Properties Of Pseudo-Peptide Containing Hydrophobic Amino Acid Grafts, Rongjun Chen, Mark E. Eccleston, Zhilian Yue, Nighel K. H Slater
Faculty of Science - Papers (Archive)
Pseudo-peptidic polymers have been synthesised by grafting l-valine (PV), l-leucine (PL) and l-phenylalanine (PP) onto the pendant carboxylic acid moieties of a pH-responsive polyamide, poly(l-lysine isophthalamide). The pH-responsive aqueous solution properties of PV-75, PL-75 and PP-75 with a stoichiometric degree of substitution of 75 mol% have been compared with those of the parent poly(l-lysine isophthalamide) using UV-visible and fluorescence spectroscopy. At low concentrations (≤0.1 mg mL-1), the grafted polymers displayed pH-dependent conformation. The pH at the onset of hydrophobic association (pHh) and the pH range over which association occurred varied significantly between the different amino acid grafts. The pHh values …
Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici
Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici
Faculty of Science - Papers (Archive)
We have demonstrated that the borono-Mannich reaction is a versatile and efficient reaction for the diastereoselective preparation of chiral 1,2-amino alcohols. These Mannich products are valuable starting materials as shown in this report by the synthesis of bioactive polyhydroxylated pyrrolizidine and indolizidine alkaloids. Initial studies, directed at the more complex Stemona alkaloids, using the borono-Mannich reaction on cyclic N-acyliminium ions are encouraging as demonstrated by the synthesis of the pyrido[1,2-a]azepine core structure of stemocurtisinol.
Synthesis Of Castanospermine, Theeraphan Machan, Andrew S. Davis, Boonsom Liawruangrath, Stephen G. Pyne
Synthesis Of Castanospermine, Theeraphan Machan, Andrew S. Davis, Boonsom Liawruangrath, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The diastereoselective synthesis of castanospermine is described in 11 synthetic steps from L-xylose. The borono-Mannich reaction between L-xylose, allylamine and (E)-styrene boronic acid gives a tetrahydroxy amine with the desired configurations for C-6, C-7, C-8 and C-8a in the target molecule. A novel pyrrolo[1,2-c]oxazol-3-one precursor was employed to allow for the control of pi-facial diastereoselectivity in an osmium(VIII)-catalysed syn-dihydroxylation (DH) reaction. A regioselective ring-opening of the cyclic sulfate derivative of the resulting diol then secured the C-1 hydroxyl group of castanospermine with the correct configuration. A Mitsunobu cyclization then provided di-O-benzyl castanospermine and …
Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton
Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton
Faculty of Science - Papers (Archive)
Pyrido- and pyrrolo[2,3-d]oxazoles can be conveniently prepared in high yield from the Ritter reaction of nitriles and in situ generated chiral cyclic N-acyliminium ions. cis-4-Hydroxy-5-acylaminopyrrolidines and cis-5-hydroxy-6-acylaminopiperidines can be readily obtained by acid hydrolysis of these bicyclic heterocyclic compounds, respectively.
Synthesis Of Novel 3'-Spirocyclic-Oxindole Derivatives And Assessment Of Their Cytostatic Activities, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Synthesis Of Novel 3'-Spirocyclic-Oxindole Derivatives And Assessment Of Their Cytostatic Activities, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Faculty of Science - Papers (Archive)
The synthesis of some novel 3′-spirocyclic-oxindole compounds, based on the spiro[indole-3,5′-isoxazolidin]-2(1H)-one, the 2′H-spiro[indole-3,6′-[1,3]oxazinane]-2,2′(1H)-dione and the 2′H-spiro[indoline-3,3′-pyrrolo[1,2-c][1,3′]oxazine]-1′,2(1H)-dione heterocyclic structures, is described. These compounds were prepared from methyl α-(2-nitrophenyl)acrylate via [1,3]-dipolar cycloaddition reactions with two acyclic nitrones and one cyclic nitrone followed by reduction of the cycloadducts and then treatment with triphosgene. Two of these compounds showed significant cytostatic activity on three cancer cell lines with GI50 values of 2.6–4.1 μM on the human breast cancer cell line, MCF-7.
Synthesis Of Benzo[C]Chromen-6-Ones Via Novel Cyclic Aryl-Pd(Ii)-Ester Enolate Intermediates, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
Synthesis Of Benzo[C]Chromen-6-Ones Via Novel Cyclic Aryl-Pd(Ii)-Ester Enolate Intermediates, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The examination of the palladium catalysed arylation reactions of mono-iodo derivatives of the phenyl and benzyl esters of benzoic acid, phenylacetic acid and dehydrocinnamic acid has resulted in the formation of benzo[c]chromen-6-ones, unexpected cinnamate and succinate products and diphenyl dimers. Many of these products can be rationalized as arising from novel cyclic ArPd(II)-enolate intermediates, formed by intramolecular C-H activation by ArPd(II).
The Synthesis Of 2',2'-Bis-Benzylisoquinolines And Their Cytostatic Activities, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
The Synthesis Of 2',2'-Bis-Benzylisoquinolines And Their Cytostatic Activities, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The novel laudanosine dimers in which two laudanosine units are linked via a C-2′ biaryl bond have been prepared by a sequence that involves formation of the biaryl bond first and then formation of the isoquinoline rings. Two of these compounds showed higher cytostatic activity on three cancer cell lines than thalicarpine.
Microwave-Assisted Facile Synthesis And Crystal Structure Of Cis-9,10,11,15-Tetrahydro-9,10[3'4']-Furanoanthracene-12,14-Dione, Weerachai Phutdhawong, Duang Buddhasukh, Stephen G. Pyne, Apinpus Rujiwatra, Chaveng Pakawatchai
Microwave-Assisted Facile Synthesis And Crystal Structure Of Cis-9,10,11,15-Tetrahydro-9,10[3'4']-Furanoanthracene-12,14-Dione, Weerachai Phutdhawong, Duang Buddhasukh, Stephen G. Pyne, Apinpus Rujiwatra, Chaveng Pakawatchai
Faculty of Science - Papers (Archive)
A facile synthesis and crystal structure of cis‐9,10,11,15‐tetrahydro‐9,10[3′,4′]‐furanoanthracene‐12,14‐dione from the reaction of anthracene and maleic anhydride in xylene in a short time and high yield using a modified commercial domestic microwave oven is reported.
Asymmetric Synthesis Of Anti-1,2-Amino Alcohols Via The Borono-Mannich Reaction: A Formal Synthesis Of (-)-Swainsonine, Christopher W. G. Au, Stephen G. Pyne
Asymmetric Synthesis Of Anti-1,2-Amino Alcohols Via The Borono-Mannich Reaction: A Formal Synthesis Of (-)-Swainsonine, Christopher W. G. Au, Stephen G. Pyne
Faculty of Science - Papers (Archive)
Chiral α-hydroxy-aldehydes generated in situ by the ADH reaction of vinyl sulfones undergo a borono-Mannich reaction with β-styrenyl boronic acid and primary amines to give anti-1,2-amino alcohols in high enantiomeric purities (ee 83-95%). This new method allows much more rapid access to these valuable chiral building blocks that has been used in a short formal synthesis (10 synthetic steps from 4-penten-1-ol) of (-)-swainsonine.
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, Modeling, And Characterization Of Conducting Polymers, Geoffrey M. Spinks, Lianbin Zhao, Weihua Li, Yanzhe Wu, Dezhi Zhou, Gordon G. Wallace
Synthesis, Modeling, And Characterization Of Conducting Polymers, Geoffrey M. Spinks, Lianbin Zhao, Weihua Li, Yanzhe Wu, Dezhi Zhou, Gordon G. Wallace
Faculty of Science - Papers (Archive)
This paper presents synthesis and characterization of polypyrrole based conducting polymers in terms of electronic and mechanical disciplines. Using the electrochemical polymerization approach, conducting polymer samples with different dimensions (length, width, and thickness) was fabricated. For each sample, both sinusoidal and step excitations were used to study its mechanical and electrical properties. An equivalent electric circuit based on constant phase element (CPE) is proposed to model such responses. Electrochemical impedance spectroscopy (EIS) method was used to identify the relationship between the dimensions of conducting polymers and model elements parameters.
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.