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Full-Text Articles in Social and Behavioral Sciences

Kinase Inhibitory, Haemolytic And Cytotoxic Activity Of Three Deep-Water Sponges From North Western Australia And Their Fatty Acid Composition, Ana Zivanovic, Natalie J. Pastro, Jane Fromont, Murray Thomson, Danielle Skropeta Nov 2013

Kinase Inhibitory, Haemolytic And Cytotoxic Activity Of Three Deep-Water Sponges From North Western Australia And Their Fatty Acid Composition, Ana Zivanovic, Natalie J. Pastro, Jane Fromont, Murray Thomson, Danielle Skropeta

Danielle Skropeta

The c-AMP dependent protein kinase (PKA) inhibition, haemolytic activity, and cytoxicity of 21 extracts obtained from North Western Australian sponges collected from depths of 84-135 m were investigated. Hexane extracts from Ircinia/Sarcotragus sp. and Geodia sp. displayed PKA inhibitory activities of 100 and 97% respectively (at 100 μg/mL), while aq. methanol extracts from Haliclona sp. exhibited potent haemolytic activity (75%) and hexane extracts from Geodia sp. were highly toxic (88%) to the brine shrimp Artemia franciscana. As the non-polar extracts gave the greatest PKA inhibition, these were further analysed by GC-MS and 29 fatty acids were identified in the highest …


Deep-Sea Natural Products, Danielle Skropeta Nov 2013

Deep-Sea Natural Products, Danielle Skropeta

Danielle Skropeta

This review covers the 390 novel marine natural products described to date from deep-water (>50 m)marine fauna, with details on the source organism, its depth and country of origin, along with anyreported biological activity of the metabolites. Relevant synthetic studies on the deep-sea naturalproducts have also been included.


Targeting Urokinase And The Transferrin Receptor With Novel, Anti-Mitotic N-Alkylisatin Cytotoxin Conjugates Causes Selective Cancer Cell Death And Reduces Tumor Growth, K Vine, V. Indira Chandran, J Locke, L Matesic, J Lee, D Skropeta, J Bremner, M Ranson Nov 2013

Targeting Urokinase And The Transferrin Receptor With Novel, Anti-Mitotic N-Alkylisatin Cytotoxin Conjugates Causes Selective Cancer Cell Death And Reduces Tumor Growth, K Vine, V. Indira Chandran, J Locke, L Matesic, J Lee, D Skropeta, J Bremner, M Ranson

Danielle Skropeta

Tumor-specific delivery of ligand-directed prodrugs can increase the therapeutic window of chemotherapeutics by maintaining efficacy whilst decreasing toxic side effects. We have previously described a series of synthetic N-alkylated isatin cytotoxins that destabilize microtubules and induce apoptosis with 10-fold greater potency than conventional anti-mitotics in vitro. Here, we report the characterization, in vitro cytotoxicity and in vivo efficacy of a lead compound, 5,7-dibromo-N-(p-hydroxymethylbenzyl)isatin (N-AI) conjugated via an esterase-labile linker (N-AIE) to two proven targeting ligands, transferrin (Tf) and plasminogen activator inhibitor type 2 (PAI-2/serpinB2). N-AI was released from N-AIE and the targeting ligands Tf/PAI-2 in an esterase-dependent manner at 37 …


Misidentification Of Tansy, Tanacetum Macrophyllum, As Yarrow, Achillea Grandifolia: A Health Risk Or Benefit?, Niko Radulovic, Polina Blagojevic, Danielle Skropeta, Aleksandra Zarubica, Bojan Zlatkovic, Radosav Palic´ Nov 2013

Misidentification Of Tansy, Tanacetum Macrophyllum, As Yarrow, Achillea Grandifolia: A Health Risk Or Benefit?, Niko Radulovic, Polina Blagojevic, Danielle Skropeta, Aleksandra Zarubica, Bojan Zlatkovic, Radosav Palic´

Danielle Skropeta

Tansy, Tanacetum macrophyllum (Waldst. & Kit.) Sch. Bip., is often misidentified by herb collectors as yarrow, Achillea grand folia Friv. With the former, cases of poisoning induced by its ingestion are well documented, but the latter is widely used for ethnopharmacological purposes. The aim of this study was to estimate, based on the volatile metabolite profiles of the two species, the potential health risk connected with their misidentification. GC and GC-MS analysis of the essential oils hydrodistilled using a Clevenger-type apparatus from A. grandifolia, T macrophyllum, and two plant samples (reputedly of A. grandifolia, but in fact mixtures of A. …


Anti-Cancer Activity Of An Acid-Labile N-Alkylisatin Conjugate Targeting The Transferrin Receptor, Vineesh Indira Chandran, Lidia Matesic, Julie Locke, Danielle Skropeta, Marie Ranson, Kara Vine Nov 2013

Anti-Cancer Activity Of An Acid-Labile N-Alkylisatin Conjugate Targeting The Transferrin Receptor, Vineesh Indira Chandran, Lidia Matesic, Julie Locke, Danielle Skropeta, Marie Ranson, Kara Vine

Danielle Skropeta

We have previously reported a series of pH-sensitive imine-linked N-alkylisatin prodrugs that are stable at pH 7.4, but readily cleaved at pH 4.5. Herein, one of the most potent prodrugs, 5,7-dibromo-N-(pmethoxybenzyl) isatin (NAI), was functionalized with a para-phenylpropionic acid linker, and the resulting NAI–imine prodrug conjugated to transferrin (Tf) to form a NAI–imine–Tf conjugate. Cytotoxicity assays revealed the conjugate was equipotent to the free drug against MCF-7 breast cancer cells, with clear selectivity patterns based on TfR levels. These results suggest that this novel isatin-based cytotoxin conjugated to a tumor targeting protein via an acid-labile linker warrants further preclinical testing.


Synthesis Of Novel Sugar Diamino Acids, M Thillakan, A Katsifis, D Skropeta Nov 2013

Synthesis Of Novel Sugar Diamino Acids, M Thillakan, A Katsifis, D Skropeta

Danielle Skropeta

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 …


Kinase Inhibitors From Marine Sponges, Danielle Skropeta, Natalie Pastro, Ana Zivanovic Nov 2013

Kinase Inhibitors From Marine Sponges, Danielle Skropeta, Natalie Pastro, Ana Zivanovic

Danielle Skropeta

Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included.


Comparison Of Polar Metabolites In Australian Deep-Sea Sponges Using Hplc-Esi-Hrms In Combination With Multivariate Analysis, L Wei, D Skropeta Nov 2013

Comparison Of Polar Metabolites In Australian Deep-Sea Sponges Using Hplc-Esi-Hrms In Combination With Multivariate Analysis, L Wei, D Skropeta

Danielle Skropeta

Abstract of paper that presented at 8th Joint Meeting of AFERP, ASP, GA, PSE and SIF, New York City, July 28 - August 1, 2012.


The Effect Of Individual N-Glycans On Enzyme Activity, Danielle Skropeta Nov 2013

The Effect Of Individual N-Glycans On Enzyme Activity, Danielle Skropeta

Danielle Skropeta

No abstract provided.


Structures, Biological Activities And Phylogenetic Relationships Of Terpenoids From Marine Ciliates Of The Genus Euplotes, Graziano Guella, Danielle Skropeta, Graziano Di Giuseppe, Fernando Dini Nov 2013

Structures, Biological Activities And Phylogenetic Relationships Of Terpenoids From Marine Ciliates Of The Genus Euplotes, Graziano Guella, Danielle Skropeta, Graziano Di Giuseppe, Fernando Dini

Danielle Skropeta

In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii) raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii) rarisetenolides and focardins containing an octahydroazulene moiety; and (iv) vannusals, with a unique C-30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large …


Domino Pericyclic Reactions Of Acyclic Conjugated (E,Z,E,E)-Tetraenes, Danielle Skropeta, Rodney Rickards Nov 2013

Domino Pericyclic Reactions Of Acyclic Conjugated (E,Z,E,E)-Tetraenes, Danielle Skropeta, Rodney Rickards

Danielle Skropeta

No abstract provided.


N-Phenethyl And N-Naphthylmethyl Isatins And Analogues As In Vitro Cytotoxic Agents, John Bremner, Stephen Pyne, Marie Ranson, Danielle Skropeta, Julie Locke, Lidia Matesic, Kara Perrow Nov 2013

N-Phenethyl And N-Naphthylmethyl Isatins And Analogues As In Vitro Cytotoxic Agents, John Bremner, Stephen Pyne, Marie Ranson, Danielle Skropeta, Julie Locke, Lidia Matesic, Kara Perrow

Danielle Skropeta

Arange of N-phenethyl,N-phenacyl, and N-(1- and 2-naphthylmethyl) derivatives of 5,7-dibromoisatin 2 were prepared byN-alkylation reactions. Their activity against human monocyte-like histiocytic lymphoma (U937), leukemia (Jurkat), and breast carcinoma (MDA-MB-231) cell lines was assessed. The results allowed further development of structureactivity relationships. The compound 5,7-dibromo-N-(1-naphthylmethyl)-1H-indole-2,3-dione 5a was the most potent against U937 cells with an IC50 value of 0.19 microM.


Exploring Marine Resources For New Pharmaceutical Applications, Danielle Skropeta Nov 2013

Exploring Marine Resources For New Pharmaceutical Applications, Danielle Skropeta

Danielle Skropeta

No abstract provided.


Complete Assignment Of The 1h And 13c Nmr Spectra Of Antimicrobial 4-Arylamino- 3-Nitrocoumarin Derivatives, Vidoslav Dekic, Niko Radulovic, Rastko Vukicevic, Biljana Dekic, Danielle Skropeta, Radosav Palic Nov 2013

Complete Assignment Of The 1h And 13c Nmr Spectra Of Antimicrobial 4-Arylamino- 3-Nitrocoumarin Derivatives, Vidoslav Dekic, Niko Radulovic, Rastko Vukicevic, Biljana Dekic, Danielle Skropeta, Radosav Palic

Danielle Skropeta

No abstract provided.


Synthesis And Hydrolytic Evaluation Of Acid-Labile Imine-Linked Cytoxic Isatin Model Systems, Lidia Matesic, Julie Locke, Kara Perrow, Marie Ranson, John Bremner, Danielle Skropeta Nov 2013

Synthesis And Hydrolytic Evaluation Of Acid-Labile Imine-Linked Cytoxic Isatin Model Systems, Lidia Matesic, Julie Locke, Kara Perrow, Marie Ranson, John Bremner, Danielle Skropeta

Danielle Skropeta

In this study a series of isatin-based, pH-sensitive aryl imine derivatives with differing aromatic substituents and substitution patterns were synthesised and their acid-catalysed hydrolysis evaluated. These derivatives were functionalised at the C3 carbonyl group of a potent N-substituted isatin cytotoxin and were stable at physiological pH but readily cleaved at pH 4.5. Observed rates of hydrolysis for the embedded imine-acid moiety were in the order para-phenylpropionic acid>phenylacetic acid (para>meta)>benzoic acid (meta>para). The ability to fine-tune hydrolysis rates in this way has potential implications for optimising imine linked, tumour targeting cytotoxin-protein conjugates


Average Mass Scan Of The Total Ion Chromatogram Versus Percentage Chemical Composition In Multivariate Statistical Comparison Of Complex Volatile Mixtures, Niko Radulovic, Polina Blagojevic, Danielle Skropeta Nov 2013

Average Mass Scan Of The Total Ion Chromatogram Versus Percentage Chemical Composition In Multivariate Statistical Comparison Of Complex Volatile Mixtures, Niko Radulovic, Polina Blagojevic, Danielle Skropeta

Danielle Skropeta

The analysis of complex volatile mixtures by gas chromatography-mass spectrometry (GC-MS) is a time-consuming process. It involves separation and identification of the components based on their retention times and fragmentation patterns, followed by determination of their relative percentages from integration of their peak areas. Herein we show that multivariate statistical analysis of the relative abundances of the m/z values obtained from the average mass scans (AMS) of the complex mixture is a faster and potentially more reliable method of assessing these mixtures. To achieve this, 15 model complex mixtures, were prepared comprising varying amounts of 10 different constituents. The AMS …


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 Nov 2013

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

Danielle Skropeta

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.


N-Glycolisation Regulates Endothelial Lipase-Mediated Phospholipid Hydrolysis In Apoe- And Apoa-I-Containing High Density Lipoproteins, Danielle Skropeta, Daniel Rader, Weijun Jin, Monica Mcmahon, Kate Shearston, Philip Barter, Kristine Mcgrath, Kerry-Anne Rye, Chatri Settasatian, Daniela Caiazza Nov 2013

N-Glycolisation Regulates Endothelial Lipase-Mediated Phospholipid Hydrolysis In Apoe- And Apoa-I-Containing High Density Lipoproteins, Danielle Skropeta, Daniel Rader, Weijun Jin, Monica Mcmahon, Kate Shearston, Philip Barter, Kristine Mcgrath, Kerry-Anne Rye, Chatri Settasatian, Daniela Caiazza

Danielle Skropeta

No abstract provided.


Cytotoxic And Anticancer Activities Of Isatin And Its Derivatives: A Comprehensive Review From 2000-2008, Marie Ranson, Danielle Skropeta, Julie Locke, Lidia Matesic, Kara Perrow Nov 2013

Cytotoxic And Anticancer Activities Of Isatin And Its Derivatives: A Comprehensive Review From 2000-2008, Marie Ranson, Danielle Skropeta, Julie Locke, Lidia Matesic, Kara Perrow

Danielle Skropeta

No abstract provided.


C-Amp Dependent Protein Kinase A Inhibitory Activity Of Six Algal Extracts From South Eastern Australia And Their Fatty Acid Composition, Ana Zivanovic, Danielle Skropeta Nov 2013

C-Amp Dependent Protein Kinase A Inhibitory Activity Of Six Algal Extracts From South Eastern Australia And Their Fatty Acid Composition, Ana Zivanovic, Danielle Skropeta

Danielle Skropeta

c-AMP dependent protein kinase (protein kinase A, PKA) is an important enzyme involved in the regulation of an increasing number of physiological processes including immune function, cardiovascular disease, memory disorders and cancer. The objective of this study was to evaluate the PKA inhibitory activity of a range of algal extracts, along with their fatty acid composition. Six algal species were investigated including two Chlorophyta (Codium dimorphum and Ulva lactuca), two Phaeophyta (Phyllospora comosa and Sargassum sp.) and two Rhodophyta (Prionitis linearis and Corallina vancouveriensis), with the order of PKA inhibitory activity of their extracts identified as follows: brown seaweeds > red …


Fatty And Volatile Oils Of The Gypsywort Lycopus Europaeus L. And The Gaussian-Like Distribution Of Its Wax Alkanes, Niko Radulovic, Marija Denic, Zorica Stojanovic-Radic, Danielle Skropeta Nov 2013

Fatty And Volatile Oils Of The Gypsywort Lycopus Europaeus L. And The Gaussian-Like Distribution Of Its Wax Alkanes, Niko Radulovic, Marija Denic, Zorica Stojanovic-Radic, Danielle Skropeta

Danielle Skropeta

The detailed analyses of the volatile essential oil and lipid profiles of the aerial parts from the blooming and fruit-forming stages of both ripe and unripe fruit of Lycopus europaeus (Lamiaceae) are presented. Both of these profiles are distinguished by components with a restricted occurrence in the Plant Kingdom. These rare compounds include (E)-hotrienol in the volatiles, numerous unusual fatty acids (such as very long chain, odd-numbered and branched-chain) in the bound lipids and a high amount of iso- and anteiso-alkanes in the epicuticular waxes. Furthermore, a Gaussian-like distribution of the relative amounts of the epicuticular wax alkanes was observed. …


Selective Release Of Potent N-Alkylisatin Based Cytotoxins Via Hydrolysis Of Ph Sensitive Imine Linkers, D Skropeta, L Matesic, J Locke, K Vine, M Ranson, J Bremner Nov 2013

Selective Release Of Potent N-Alkylisatin Based Cytotoxins Via Hydrolysis Of Ph Sensitive Imine Linkers, D Skropeta, L Matesic, J Locke, K Vine, M Ranson, J Bremner

Danielle Skropeta

No abstract provided.


Chemotaxonomy Of The Peppergrass Lepidium Coronopus (L.) Al-Shehbaz (Syn. Coronopus Squamatus) Based On Its Volatile Glucosinolate Autolysis Products, Niko Radulovic, Bojan Zlatkovic, Danielle Skropeta, Radosav Palic´ Nov 2013

Chemotaxonomy Of The Peppergrass Lepidium Coronopus (L.) Al-Shehbaz (Syn. Coronopus Squamatus) Based On Its Volatile Glucosinolate Autolysis Products, Niko Radulovic, Bojan Zlatkovic, Danielle Skropeta, Radosav Palic´

Danielle Skropeta

The genus Lepidium comprises approximately 175 different plant species commonly referred to as peppergrasses or pepperworts ( Al-Shehbaz, 1997 and Mummenhoff et al., 2001), which occur worldwide apart from the polar regions where they are considered rare in the Arctic and are absent from Antarctica. Lepidium is a comparatively large genus belonging to the mustard family Brassicaceae. Lepidium coronopus (L.) Al-Shehbaz, a representative of the genus, is a herbaceous annual to biennial plant that belongs to the tribe Lepidieae and has previously been described by the following synonymous species: Coronopus squamatus (Forsskal) Ascherson; C. squamatus subsp. conradi (Muschler) Maire; C. …


Learning How To Be An Academic - The Story Of A New Academic In The Sciences, Danielle Skropeta Nov 2013

Learning How To Be An Academic - The Story Of A New Academic In The Sciences, Danielle Skropeta

Danielle Skropeta

No abstract provided.


Solid-State And Solution-Phase Conformations Of Pseudoproline-Containing Dipeptides, James R. Cochrane, Nima Sayyadi, Danielle Skropeta, Peter Turner, Jack K. Clegg, Katrina A. Jolliffe Nov 2013

Solid-State And Solution-Phase Conformations Of Pseudoproline-Containing Dipeptides, James R. Cochrane, Nima Sayyadi, Danielle Skropeta, Peter Turner, Jack K. Clegg, Katrina A. Jolliffe

Danielle Skropeta

The conformations of 14 threonine-derived pseudoproline-containing dipeptides (including four d-allo-Thr derivatives) have been investigated by NMR. In solution, the major conformer observed for all dipeptides is that in which the amide bond between the pseudoproline and the preceding amino acid is cis. For dipeptides in which the N-terminus is protected, the ratio of cis- to trans-conformers does not depend significantly on the side chain of the N-terminal amino acid, or the stereochemistry of the Thr residue. However, for dipeptides bearing a free N-terminus, there are significant differences in the ratios of cis- to trans-conformers depending on the side chain present. …