37 results on '"Andrew Crombie"'
Search Results
2. Evaluation of Benzguinols as Next-Generation Antibiotics for the Treatment of Multidrug-Resistant Bacterial Infections
- Author
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Hang Thi Nguyen, Mahmud T. Morshed, Daniel Vuong, Andrew Crombie, Ernest Lacey, Sanjay Garg, Hongfei Pi, Lucy Woolford, Henrietta Venter, Stephen W. Page, Andrew M. Piggott, Darren J. Trott, and Abiodun D. Ogunniyi
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Staphylococcus pseudintermedius ,Staphylococcus aureus ,benzguinols ,nidulins ,Gram-negative ,antimicrobial resistance ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Our recent focus on the “lost antibiotic” unguinol and related nidulin-family fungal natural products identified two semisynthetic derivatives, benzguinols A and B, with unexpected in vitro activity against Staphylococcus aureus isolates either susceptible or resistant to methicillin. Here, we show further activity of the benzguinols against methicillin-resistant isolates of the animal pathogen Staphylococcus pseudintermedius, with minimum inhibitory concentration (MIC) ranging 0.5–1 μg/mL. When combined with sub-inhibitory concentrations of colistin, the benzguinols demonstrated synergy against Gram-negative reference strains of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa (MICs of 1–2 μg/mL in the presence of colistin), whereas the benzguinols alone had no activity. Administration of three intraperitoneal (IP) doses of 20 mg/kg benzguinol A or B to mice did not result in any obvious adverse clinical or pathological evidence of acute toxicity. Importantly, mice that received three 20 mg/kg IP doses of benzguinol A or B at 4 h intervals exhibited significantly reduced bacterial loads and longer survival times than vehicle-only treated mice in a bioluminescent S. aureus murine sepsis challenge model. We conclude that the benzguinols are potential candidates for further development for specific treatment of serious bacterial infections as both stand-alone antibiotics and in combination with existing antibiotic classes.
- Published
- 2021
- Full Text
- View/download PDF
3. Aspergillus Sydowii Marine Fungal Bloom in Australian Coastal Waters, Its Metabolites and Potential Impact on Symbiodinium Dinoflagellates
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Aiko Hayashi, Andrew Crombie, Ernest Lacey, Anthony J. Richardson, Daniel Vuong, Andrew M. Piggott, and Gustaaf Hallegraeff
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Aspergillus sydowii ,Symbiodinium ,secondary metabolites ,sydonic acid ,sydowinin ,sydowinol ,sydonol ,coral disease ,maximum quantum yield (Fv/Fm) ,Biology (General) ,QH301-705.5 - Abstract
Dust has been widely recognised as an important source of nutrients in the marine environment and as a vector for transporting pathogenic microorganisms. Disturbingly, in the wake of a dust storm event along the eastern Australian coast line in 2009, the Continuous Plankton Recorder collected masses of fungal spores and mycelia (~150,000 spores/m3) forming a floating raft that covered a coastal area equivalent to 25 times the surface of England. Cultured A. sydowii strains exhibited varying metabolite profiles, but all produced sydonic acid, a chemotaxonomic marker for A. sydowii. The Australian marine fungal strains share major metabolites and display comparable metabolic diversity to Australian terrestrial strains and to strains pathogenic to Caribbean coral. Secondary colonisation of the rafts by other fungi, including strains of Cladosporium, Penicillium and other Aspergillus species with distinct secondary metabolite profiles, was also encountered. Our bioassays revealed that the dust-derived marine fungal extracts and known A. sydowii metabolites such as sydowic acid, sydowinol and sydowinin A adversely affect photophysiological performance (Fv/Fm) of the coral reef dinoflagellate endosymbiont Symbiodinium. Different Symbiodinium clades exhibited varying sensitivities, mimicking sensitivity to coral bleaching phenomena. The detection of such large amounts of A. sydowii following this dust storm event has potential implications for the health of coral environments such as the Great Barrier Reef.
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- 2016
- Full Text
- View/download PDF
4. Genome Mining of Aspergillus hancockii Unearths Cryptic Polyketide Hancockinone A Featuring a Prenylated 6/6/6/5 Carbocyclic Skeleton
- Author
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Si Shu, Hang Li, Andrew Crombie, John A. Kalaitzis, Yit-Heng Chooi, Ernest Lacey, Andrew M. Piggott, Zhuo Shang, and Daniel Vuong
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Aspergillus ,biology ,010405 organic chemistry ,Stereochemistry ,Chemistry ,Organic Chemistry ,Cytochrome P450 ,010402 general chemistry ,biology.organism_classification ,01 natural sciences ,Biochemistry ,3. Good health ,0104 chemical sciences ,Polyketide ,Prenylation ,Polyketide synthase ,Gene cluster ,biology.protein ,Heterologous expression ,Physical and Theoretical Chemistry ,Transcription factor - Abstract
Activation of a cryptic polyketide synthase gene cluster hkn from Aspergillus hancockii via overexpression of the gene-cluster-specific transcription factor HknR led to the discovery of a novel polycyclic metabolite, which we named hancockinone A. The compound features an unprecedented prenylated 6/6/6/5 tetracarbocyclic skeleton and shows moderate antibacterial activity. Heterologous expression, substrate feeding, and in vitro assays confirmed the role of cytochrome P450 HknE in constructing the five-membered ring in hancockinone A from the precursor neosartoricin B.
- Published
- 2021
5. Semisynthesis and biological evaluation of a focused library of unguinol derivatives as next-generation antibiotics
- Author
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Andrew M. Piggott, Abiodun D. Ogunniyi, Mahmud T. Morshed, Hang T. Nguyen, Andrew Crombie, Darren J. Trott, Stephen W. Page, Daniel Vuong, and Ernest Lacey
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Methicillin-Resistant Staphylococcus aureus ,Stereochemistry ,Drug Evaluation, Preclinical ,Chemistry Techniques, Synthetic ,Microbial Sensitivity Tests ,01 natural sciences ,Biochemistry ,Cell Line ,03 medical and health sciences ,chemistry.chemical_compound ,In vivo ,Animals ,Potency ,Structure–activity relationship ,Physical and Theoretical Chemistry ,0303 health sciences ,010405 organic chemistry ,030306 microbiology ,Chemistry ,Depsidone ,Organic Chemistry ,Semisynthesis ,In vitro ,Anti-Bacterial Agents ,0104 chemical sciences ,Pharmacophore ,Antibacterial activity ,Heterocyclic Compounds, 3-Ring - Abstract
In this study, we report the semisynthesis and in vitro biological evaluation of thirty-four derivatives of the fungal depsidone antibiotic, unguinol. Initially, the semisynthetic modifications were focused on the two free hydroxy groups (3-OH and 8-OH), the three free aromatic positions (C-2, C-4 and C-7), the butenyl side chain and the depsidone ester linkage. Fifteen first-generation unguinol analogues were synthesised and screened against a panel of bacteria, fungi and mammalian cells to formulate a basic structure activity relationship (SAR) for the unguinol pharmacophore. Based on the SAR studies, we synthesised a further nineteen second-generation analogues, specifically aimed at improving the antibacterial potency of the pharmacophore. In vitro antibacterial activity testing of these compounds revealed that 3-O-(2-fluorobenzyl)unguinol and 3-O-(2,4-difluorobenzyl)unguinol showed potent activity against both methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MIC 0.25–1 μg mL−1) and are promising candidates for further development in vivo.
- Published
- 2021
6. Talauxins: Hybrid Phenalenone Dimers from Talaromyces stipitatus
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Peter Karuso, Daniel Vuong, Andrew M. Piggott, Nirmal Chaudhary, Andrew Crombie, and Ernest Lacey
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Pharmacology ,chemistry.chemical_classification ,010405 organic chemistry ,Talaromyces stipitatus ,Stereochemistry ,Methyl acetate ,Organic Chemistry ,Extraction (chemistry) ,Pharmaceutical Science ,01 natural sciences ,In vitro ,0104 chemical sciences ,Analytical Chemistry ,Amino acid ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,Complementary and alternative medicine ,chemistry ,Yield (chemistry) ,Drug Discovery ,Molecular Medicine ,Density functional theory - Abstract
Cultivation and extraction of the fungus Talaromyces stipitatus led to the isolation of five new oxyphenalenone-amino acid hybrids, which were named talauxins E, Q, V, L, and I based on the corresponding one-letter amino acid codes, along with their putative biosynthetic precursor, duclauxin. The rapid reaction of duclauxin with amino acids to produce talauxins was demonstrated in vitro and exploited to generate a small library of natural and unnatural talauxins. Talauxin V was shown to undergo spontaneous elimination of methyl acetate to yield the corresponding neoclauxin scaffold. This process was modeled using density functional theory calculations, revealing a dramatic change in conformation resulting from the syn elimination of methyl acetate.
- Published
- 2020
7. The chemical gymnastics of enterocin: evidence for stereodivergence in Nature
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Michael S. Cowled, Daniel Vuong, Peter Karuso, Andrew Crombie, Ernest Lacey, and Andrew M. Piggott
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chemistry.chemical_classification ,Natural product ,Gymnastics ,biology ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Kinetics ,Sequence (biology) ,010402 general chemistry ,biology.organism_classification ,01 natural sciences ,Biochemistry ,In vitro ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Polyketide ,Enzyme ,chemistry ,Physical and Theoretical Chemistry ,Bacteria - Abstract
Stereodivergence in Nature encapsulates both enzymatic (biosynthetic) and non-enzymatic (chemical) diversification of natural product scaffolds arising from a single biosynthetic pathway. Herein, we report a fascinating example of stereodivergence for the bacterial polyketide enterocin, which we observed to undergo a series of facile skeletal rearrangements in solution, leading to four distinct isomeric structures. The final distribution of the four isomers was found to be highly sensitive to the conditions used, including solvent, temperature and pH. In this study, we have investigated the kinetics of these isomeric conversions, and using a combination of DFT and thermochemical calculations, were able to establish a mechanism detailing a concerted rearrangement and an unusual "gymnastic" sequence of pseudo-chair-boat conformational interconversions. In addition to these kinetic and mechanistic studies, we also performed a semisynthetic study aimed at stabilising the enterocin scaffold. In total, seven analogues of enterocin were synthesised and investigated for their stability and in vitro activity against a panel of bacteria, fungi, plants and mammalian cells.
- Published
- 2020
8. Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis
- Author
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Ernest Lacey, Yit-Heng Chooi, Andrew Crombie, Peter J. Rutledge, Peter Turner, John A. Kalaitzis, Daniel Vuong, Cameron L.M. Gilchrist, Andrew M. Piggott, Heather J. Lacey, and John I. Pitt
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Metabolite ,Fungus ,010402 general chemistry ,01 natural sciences ,Full Research Paper ,lcsh:QD241-441 ,Terpene ,chemistry.chemical_compound ,lcsh:Organic chemistry ,Biosynthesis ,Gene cluster ,lcsh:Science ,Aspergillus ,biology ,secondary metabolites ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,sesquiterpenoid ,biology.organism_classification ,In vitro ,0104 chemical sciences ,Biochemistry ,lcsh:Q ,drimane ,biosynthesis ,terpenes ,Bacteria - Abstract
Chemical investigation of an undescribed Australian fungus, Aspergillus nanangensis, led to the identification of the nanangenines – a family of seven new and three previously reported drimane sesquiterpenoids. The structures of the nanangenines were elucidated by detailed spectroscopic analysis supported by single crystal X-ray diffraction studies. The compounds were assayed for in vitro activity against bacteria, fungi, mammalian cells and plants. Bioinformatics analysis, including comparative analysis with other acyl drimenol-producing Aspergilli, led to the identification of a putative nanangenine biosynthetic gene cluster that corresponds to the proposed biosynthetic pathway for nanangenines.
- Published
- 2019
9. Genome Mining of
- Author
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Hang, Li, Si, Shu, John A, Kalaitzis, Zhuo, Shang, Daniel, Vuong, Andrew, Crombie, Ernest, Lacey, Andrew M, Piggott, and Yit-Heng, Chooi
- Subjects
Polyketides - Abstract
Activation of a cryptic polyketide synthase gene cluster
- Published
- 2021
10. SEREEL2 – a new laser single-event effects test system with benchmark results
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Richard E. Sharp, Andrew Crombie, and Chris Chong
- Published
- 2021
11. The Geology of the Island of Arran: From Original Survey
- Author
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Ramsay, Andrew Crombie
- Published
- 2011
- Full Text
- View/download PDF
12. Production of novel pladienolide analogues through native expression of a pathway-specific activator
- Author
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Ernest Lacey, Thomas J. Booth, Andrew M. Piggott, Daniel Vuong, Andrew Crombie, Barrie Wilkinson, and John A. Kalaitzis
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0106 biological sciences ,0303 health sciences ,Spliceosome ,Natural product ,Activator (genetics) ,Chemistry ,General Chemistry ,01 natural sciences ,Small molecule ,03 medical and health sciences ,Polyketide ,chemistry.chemical_compound ,Biochemistry ,Biosynthesis ,010608 biotechnology ,IC50 ,030304 developmental biology ,Biosynthetic genes - Abstract
Aberrant splicing of pre-mRNA is implicated in many human genetic disorders. Small molecules that target the spliceosome are important leads as therapeutics and research tools, and one compound of significant interest is the polyketide natural product pladienolide B. Here, we describe the reactivation of quiescent pladienolide B production in the domesticated lab strain Streptomyces platensis AS6200 by overexpression of the pathway-specific activator PldR. The resulting dysregulation of the biosynthetic genes led to the accumulation and isolation of five additional intermediate or shunt metabolites of pladienolide B biosynthesis, including three previously unreported congeners. These compounds likely comprise the entire pladienolide biosynthetic pathway and demonstrate the link between polyketide tailoring reactions and bioactivity, particularly the importance of the 18,19-epoxide. Each congener demonstrated specific inhibitory activity against mammalian cell lines, with successive modifications leading to increased activity (IC50: 8 mM to 5 μM)., Reactivation of quiescent polyketide production in a domesticated lab strain.
- Published
- 2021
13. Evaluation of Benzguinols as Next-Generation Antibiotics for the Treatment of Multidrug-Resistant Bacterial Infections
- Author
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Sanjay Garg, Andrew Crombie, Stephen W. Page, Henrietta Venter, Darren J. Trott, Hang Thi Nguyen, Andrew M. Piggott, Abiodun D. Ogunniyi, Daniel Vuong, Mahmud T. Morshed, Hongfei Pi, Ernest Lacey, Lucy Woolford, Nguyen, Hang Thi, Morshed, Mahmud T, Vuong, Daniel, Crombie, Andrew, Lacey, Ernest, Garg, Sanjay, Pi, Hongfei, Woolford, Lucy, Venter, Henrietta, Page, Stephen W, Piggott, Andrew M, Trott, Darren J, and Ogunniyi, Abiodun D
- Subjects
0301 basic medicine ,Microbiology (medical) ,Staphylococcus aureus ,Staphylococcus pseudintermedius ,medicine.drug_class ,030106 microbiology ,Antibiotics ,RM1-950 ,minimum inhibitory concentration ,medicine.disease_cause ,Biochemistry ,Microbiology ,Article ,03 medical and health sciences ,Minimum inhibitory concentration ,Antibiotic resistance ,gramnegative ,medicine ,Pharmacology (medical) ,colistin ,antimicrobial resistance ,General Pharmacology, Toxicology and Pharmaceutics ,benzguinols ,biology ,Pseudomonas aeruginosa ,biology.organism_classification ,Gram-negative ,Acinetobacter baumannii ,030104 developmental biology ,Infectious Diseases ,Colistin ,cytotoxicity ,Therapeutics. Pharmacology ,bioluminescent mouse model ,minimuminhibitory concentration ,medicine.drug ,nidulins - Abstract
Our recent focus on the “lost antibiotic” unguinol and related nidulin-family fungal natural products identified two semisynthetic derivatives, benzguinols A and B, with unexpected in vitro activity against Staphylococcus aureus isolates either susceptible or resistant to methicillin. Here, we show further activity of the benzguinols against methicillin-resistant isolates of the animal pathogen Staphylococcus pseudintermedius, with minimum inhibitory concentration (MIC) ranging 0.5–1 μg/mL. When combined with sub-inhibitory concentrations of colistin, the benzguinols demonstrated synergy against Gram-negative reference strains of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa (MICs of 1–2 μg/mL in the presence of colistin), whereas the benzguinols alone had no activity. Administration of three intraperitoneal (IP) doses of 20 mg/kg benzguinol A or B to mice did not result in any obvious adverse clinical or pathological evidence of acute toxicity. Importantly, mice that received three 20 mg/kg IP doses of benzguinol A or B at 4 h intervals exhibited significantly reduced bacterial loads and longer survival times than vehicle-only treated mice in a bioluminescent S. aureus murine sepsis challenge model. We conclude that the benzguinols are potential candidates for further development for specific treatment of serious bacterial infections as both stand-alone antibiotics and in combination with existing antibiotic classes.
- Published
- 2021
14. Talauxins: Hybrid Phenalenone Dimers from
- Author
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Nirmal K, Chaudhary, Andrew, Crombie, Daniel, Vuong, Ernest, Lacey, Andrew M, Piggott, and Peter, Karuso
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Molecular Structure ,Talaromyces ,Chromones ,Molecular Conformation ,Phenalenes ,Nuclear Magnetic Resonance, Biomolecular - Abstract
Cultivation and extraction of the fungus
- Published
- 2020
15. Eukaryote-Conserved Methylarginine Is Absent in Diplomonads and Functionally Compensated in Giardia
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Samantha J. Emery-Corbin, Brendan R E Ansell, Andreas J. Stroehlein, Crystal Cooper, Daniel Vuong, Melanie Bahlo, Swapnil Tichkule, Ernest Lacey, Marc R. Wilkins, Staffan G. Svärd, Robin B. Gasser, Balu Balan, Melissa J. Davis, Aaron R. Jex, Soroor Hediyeh-Zadeh, Joshua J. Hamey, Bernard V. McInerney, and Andrew Crombie
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Methylarginine ,Proteome ,Computational biology ,medicine.disease_cause ,AcademicSubjects/SCI01180 ,Methylation ,Evolutionsbiologi ,03 medical and health sciences ,Methyllysine ,chemistry.chemical_compound ,Diplomonadida ,Genetics ,medicine ,Gene family ,Protein Methyltransferases ,Trophozoites ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Discoveries ,030304 developmental biology ,0303 health sciences ,Evolutionary Biology ,biology ,methylproteome ,Giardia ,030302 biochemistry & molecular biology ,AcademicSubjects/SCI01130 ,Metamonada ,Biochemistry and Molecular Biology ,Protist ,methylarginine ,biology.organism_classification ,Biological Evolution ,Cytoskeletal Proteins ,chemistry ,Eukaryote ,methyllysine ,Biokemi och molekylärbiologi - Abstract
Methylation is a common posttranslational modification of arginine and lysine in eukaryotic proteins. Methylproteomes are best characterized for higher eukaryotes, where they are functionally expanded and evolved complex regulation. However, this is not the case for protist species evolved from the earliest eukaryotic lineages. Here, we integrated bioinformatic, proteomic, and drug-screening data sets to comprehensively explore the methylproteome of Giardia duodenalis—a deeply branching parasitic protist. We demonstrate that Giardia and related diplomonads lack arginine-methyltransferases and have remodeled conserved RGG/RG motifs targeted by these enzymes. We also provide experimental evidence for methylarginine absence in proteomes of Giardia but readily detect methyllysine. We bioinformatically infer 11 lysine-methyltransferases in Giardia, including highly diverged Su(var)3-9, Enhancer-of-zeste and Trithorax proteins with reduced domain architectures, and novel annotations demonstrating conserved methyllysine regulation of eukaryotic elongation factor 1 alpha. Using mass spectrometry, we identify more than 200 methyllysine sites in Giardia, including in species-specific gene families involved in cytoskeletal regulation, enriched in coiled-coil features. Finally, we use known methylation inhibitors to show that methylation plays key roles in replication and cyst formation in this parasite. This study highlights reduced methylation enzymes, sites, and functions early in eukaryote evolution, including absent methylarginine networks in the Diplomonadida. These results challenge the view that arginine methylation is eukaryote conserved and demonstrate that functional compensation of methylarginine was possible preceding expansion and diversification of these key networks in higher eukaryotes.
- Published
- 2020
16. A study of the chemical diversity of macroalgae from South Eastern Australia
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Heather J. Lacey, Andrew Crombie, Ernest Lacey, Matvi Kaplan, Andrew M. Piggott, and Daniel Vuong
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0301 basic medicine ,Agrochemical ,media_common.quotation_subject ,Chlorophyta ,Biology ,Secondary metabolite ,Phaeophyta ,01 natural sciences ,03 medical and health sciences ,Genus ,Drug Discovery ,medicine ,media_common ,Pharmacology ,010405 organic chemistry ,Ecology ,business.industry ,Australia ,Biodiversity ,General Medicine ,Seaweed ,biology.organism_classification ,0104 chemical sciences ,030104 developmental biology ,Productivity (ecology) ,Chemical diversity ,Rhodophyta ,business ,South eastern ,medicine.drug ,Diversity (politics) - Abstract
Macroalgae are a rich source of biologically active chemical diversity for pharmaceutical and agrichemical discovery. However, the ability to understand the complexities of their chemical diversity will dictate whether these natural products have a place in modern discovery paradigms. In this study, we examined the relationship between secondary metabolite production and biological activity for a cohort of 127 macroalgae samples collected from various locations across South Eastern Australia. Approximately 20% of the macroalgae samples showed high levels of chemical diversity and productivity, which also correlated strongly with bioactivity. These "talented" species represent sustainable sources of metabolites that may be readily harvested for large-scale production. At a taxonomic level, significant differences in metabolite production and diversity were observed between Chlorophyta, Rhodophyta and Phaeophyta. For each talented species, the cometabolite pattern was unique to that species, with closely related species within the same genus displaying very different profiles. Despite over 50years of investigation, we estimate that more than two-thirds of the chemical diversity of macroalgae remains unknown to science. By understanding the physicochemical properties and distribution patterns of metabolites, it is possible to make reasoned judgements about sustainable sourcing of macroalgae for biodiscovery.
- Published
- 2018
17. Expanding antibiotic chemical space around the nidulin pharmacophore
- Author
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Andrew Crombie, Ernest Lacey, Andrew M. Piggott, Daniel Vuong, Peter Karuso, Mahmud T. Morshed, and Alastair E. Lacey
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0301 basic medicine ,medicine.drug_class ,Antibiotics ,Secondary Metabolism ,Secondary metabolite ,Depsides ,Biochemistry ,Lactones ,Mice ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Polyketide synthase ,medicine ,Animals ,Physical and Theoretical Chemistry ,biology ,Chemistry ,Depsidone ,Organic Chemistry ,Aspergillus unguis ,biology.organism_classification ,Drug Resistance, Multiple ,Anti-Bacterial Agents ,Aspergillus ,030104 developmental biology ,biology.protein ,Pharmacophore ,Dibenzoxepins ,Bacteria ,medicine.drug - Abstract
Reinvestigating antibiotic scaffolds that were identified during the Golden Age of antibiotic discovery, but have long since been "forgotten", has proven to be an effective strategy for delivering next-generation antibiotics capable of combatting multidrug-resistant superbugs. In this study, we have revisited the trichloro-substituted depsidone, nidulin, as a selective and unexploited antibiotic lead produced by the fungus Aspergillus unguis. Manipulation of halide ion concentration proved to be a powerful tool for modulating secondary metabolite production and triggering quiescent pathways in A. unguis. Supplementation of the culture media with chloride resulted in a shift in co-metabolite profile to dichlorounguinols and nornidulin at the expense of the non-chlorinated parent, unguinol. Surprisingly, only marginal enhancement of nidulin was observed, suggesting O-methylation may be rate-limiting. Similarly, supplementation of the media with bromide led to the production of the corresponding bromo-analogues, but also resulted in a novel family of depsides, the unguidepsides. Unexpectedly, depletion of chloride from the media halted the biosynthesis of the non-chlorinated parent compound, unguinol, and redirected biosynthesis to a novel family of ring-opened analogues, the unguinolic acids. Supplementation of the media with a range of unnatural salicylic acids failed to yield the corresponding nidulin analogues, suggesting the compounds may be biosynthesised by a single polyketide synthase. In total, 12 new and 11 previously reported nidulin analogues were isolated, characterised and assayed for in vitro activity against a panel of bacteria, fungi and mammalian cells, providing a comprehensive structure-activity profile for the nidulin scaffold.
- Published
- 2018
18. On the science of geology and its applications : being the introductory lecture to the course of geology, session 1851-1852 /
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Ramsay, Andrew C. (Andrew Crombie), Museum Victoria, and Ramsay, Andrew C. (Andrew Crombie)
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Geology - Published
- 1852
19. The physical geology and geography of Great Britain : a manual of British geology /
- Author
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Ramsay, A. C. Sir, (Andrew Crombie), 1814-1891, Woodward, Horace B. (Horace Bolingbroke), 1848-1914, University of California Libraries (archive.org), Ramsay, A. C. Sir, (Andrew Crombie), 1814-1891, and Woodward, Horace B. (Horace Bolingbroke), 1848-1914
- Subjects
Geology ,Great Britain - Published
- 1878
20. A descriptive catalogue of the rock specimens in the Museum of Practical Geology /
- Author
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Museum of Practical Geology (Great Britain), Bauerman, Hilary, 1833-1909, Bristow, Henry W. (Henry William), 1817-1889, Ramsay, Andrew Crombie, Sir, 1814-1891, Natural History Museum Library, London, Museum of Practical Geology (Great Britain), Bauerman, Hilary, 1833-1909, Bristow, Henry W. (Henry William), 1817-1889, and Ramsay, Andrew Crombie, Sir, 1814-1891
- Published
- 1858
21. A descriptive catalogue of the rock specimens in the Museum of Practical Geology
- Author
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Museum of Practical Geology (Great Britain), Bauerman, Hilary, 1833-1909, Bristow, Henry W. (Henry William), 1817-1889, Ramsay, Andrew Crombie, Sir, 1814-1891, Natural History Museum Library, London, Museum of Practical Geology (Great Britain), Bauerman, Hilary, 1833-1909, Bristow, Henry W. (Henry William), 1817-1889, and Ramsay, Andrew Crombie, Sir, 1814-1891
22. Discovery and Heterologous Biosynthesis of the Burnettramic Acids: Rare PKS-NRPS-Derived Bolaamphiphilic Pyrrolizidinediones from an Australian Fungus, Aspergillus burnettii
- Author
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Ernest Lacey, Cameron L.M. Gilchrist, Hang Li, Yit-Heng Chooi, Andrew Crombie, Daniel Vuong, Andrew M. Piggott, Heather J. Lacey, and John I. Pitt
- Subjects
Pyrrolidines ,Heterologous ,Secondary Metabolism ,Fungus ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Heterocyclic Compounds, 2-Ring ,chemistry.chemical_compound ,Biosynthesis ,Isomerism ,Aspergillus nidulans ,Gene cluster ,Physical and Theoretical Chemistry ,Secondary metabolism ,Comparative genomics ,Aspergillus ,biology ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Australia ,biology.organism_classification ,3. Good health ,0104 chemical sciences ,Anti-Bacterial Agents ,Multigene Family ,Mannose ,Oxidation-Reduction - Abstract
The burnettramic acids are a new class of antibiotics from an Australian fungus Aspergillus burnettii. The rare bolaamphiphilic scaffold consists of β-d-mannose linked to a pyrrolizidinedione unit via a 26-carbon chain. The most abundant metabolite displayed potent in vitro antifungal activity. Comparative genomics identified the hybrid PKS-NRPS bua gene cluster, which was verified by heterologous pathway reconstitution in Aspergillus nidulans.
- Published
- 2019
23. Draft Genome Sequence of Methylocella silvestris TVC, a Facultative Methanotroph Isolated from Permafrost
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Jing, Wang, Kan, Geng, Muhammad, Farhan Ul Haque, Andrew, Crombie, Lorna E, Street, Philip A, Wookey, Ke, Ma, J Colin, Murrell, and Jennifer, Pratscher
- Subjects
Prokaryotes - Abstract
Permafrost environments play a crucial role in global carbon and methane cycling. We report here the draft genome sequence of Methylocella silvestris TVC, a new facultative methanotroph strain, isolated from the Siksik Creek catchment in the continuous permafrost zone of Inuvik (Northwest Territories, Canada).
- Published
- 2018
24. Amycolatopsins A-C: antimycobacterial glycosylated polyketide macrolides from the Australian soil Amycolatopsis sp. MST-108494
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Robert J. Capon, Zeinab G. Khalil, Ernest Lacey, Angela A. Salim, Andrew Crombie, Antje Blumenthal, and Daniel Vuong
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medicine.drug_class ,Stereochemistry ,Microbial Sensitivity Tests ,Biology ,010402 general chemistry ,Antimycobacterial ,01 natural sciences ,Cell Line ,Mycobacterium tuberculosis ,Hydroxylation ,Polyketide ,chemistry.chemical_compound ,Structure-Activity Relationship ,Drug Discovery ,medicine ,Structure–activity relationship ,Humans ,Tuberculosis ,Soil Microbiology ,Pharmacology ,Mycobacterium bovis ,010405 organic chemistry ,biology.organism_classification ,0104 chemical sciences ,Anti-Bacterial Agents ,Actinobacteria ,Biochemistry ,chemistry ,Polyketides ,Fermentation ,Macrolides ,Bacteria - Abstract
A southern Australian soil isolate, Amycolatopsis sp. MST-108494, was subjected to a panel of fermentation and media optimization trials, supported by analytical chemical profiling, to detect and enhance production of a rare class of secondary metabolites. Chemical fractionation of two complementary fermentations yielded three new polyketides, identified by detailed spectroscopic analysis as the glycosylated macrolactones, amycolatopsins A (1), B (2) and C (3), closely related to the ammocidins and apoptolidins. Amycolatopsins 1 and 3 selectively inhibited growth of Mycobacterium bovis (BCG) and Mycobacterium tuberculosis (H37Rv) when compared with other Gram-positive or Gram-negative bacteria, with 3 exhibiting low levels of cytotoxicity toward mammalian cells. Thus, our data reveal promising structure activity relationship correlations where the antimycobacterial properties of amycolatopsins are enhanced by hydroxylation of the 6-Me (that is, 1 and 3), whereas mammalian cytotoxicity is decreased by hydrolysis of the disaccharide moiety (that is, 3).
- Published
- 2017
25. Aspergillus Sydowii Marine Fungal Bloom in Australian Coastal Waters, Its Metabolites and Potential Impact on Symbiodinium Dinoflagellates
- Author
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Anthony J. Richardson, Gustaaf M. Hallegraeff, Aiko Hayashi, Ernest Lacey, Andrew M. Piggott, Daniel Vuong, and Andrew Crombie
- Subjects
0301 basic medicine ,Coral bleaching ,Aspergillus sydowii ,Symbiodinium ,secondary metabolites ,sydonic acid ,sydowinin ,sydowinol ,sydonol ,coral disease ,maximum quantum yield (Fv/Fm) ,Coral ,030106 microbiology ,Secondary Metabolism ,Pharmaceutical Science ,Secondary metabolite ,Article ,03 medical and health sciences ,Drug Discovery ,Botany ,medicine ,Animals ,lcsh:QH301-705.5 ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,geography ,geography.geographical_feature_category ,biology ,Coral Reefs ,fungi ,Australia ,Fungi ,Dinoflagellate ,Dust ,Coral reef ,Spores, Fungal ,biology.organism_classification ,Aspergillus ,030104 developmental biology ,lcsh:Biology (General) ,Dinoflagellida ,Cladosporium ,medicine.drug - Abstract
Dust has been widely recognised as an important source of nutrients in the marine environment and as a vector for transporting pathogenic microorganisms. Disturbingly, in the wake of a dust storm event along the eastern Australian coast line in 2009, the Continuous Plankton Recorder collected masses of fungal spores and mycelia (~150,000 spores/m3) forming a floating raft that covered a coastal area equivalent to 25 times the surface of England. Cultured A. sydowii strains exhibited varying metabolite profiles, but all produced sydonic acid, a chemotaxonomic marker for A. sydowii. The Australian marine fungal strains share major metabolites and display comparable metabolic diversity to Australian terrestrial strains and to strains pathogenic to Caribbean coral. Secondary colonisation of the rafts by other fungi, including strains of Cladosporium, Penicillium and other Aspergillus species with distinct secondary metabolite profiles, was also encountered. Our bioassays revealed that the dust-derived marine fungal extracts and known A. sydowii metabolites such as sydowic acid, sydowinol and sydowinin A adversely affect photophysiological performance (Fv/Fm) of the coral reef dinoflagellate endosymbiont Symbiodinium. Different Symbiodinium clades exhibited varying sensitivities, mimicking sensitivity to coral bleaching phenomena. The detection of such large amounts of A. sydowii following this dust storm event has potential implications for the health of coral environments such as the Great Barrier Reef.
- Published
- 2016
26. The Geology of the Island of Arran
- Author
-
Andrew Crombie Ramsay
- Abstract
The Scottish geologist Andrew Crombie Ramsay (1814–91), best remembered for his work on glaciation, made his name with this study, which originated in holiday visits to Arran. Encouraged by John Nichol of Glasgow University, Ramsay had prepared a geological map of the island for the British Association's visit in 1839, and was to have led a field excursion and lectured to the delegates there, but missed the boat. Nichol arranged for Ramsay's work to be published the following year. It attracted the attention of Roderick Murchison, who found him employment with the Geological Survey, and Ramsay later succeeded Murchison as its director and was knighted on his retirement in 1881. The book, designed as a practical visitor's guide for both amateur and professional geologists, is organised by district with reference to specific geological features, and Ramsay provides full explanations, diagrams and engravings to make his work accessible to non-specialists.
- Published
- 2011
27. EXPLANATION OF THE SECTIONS
- Author
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Andrew Crombie Ramsay
- Published
- 2011
28. Development of a system for genetic manipulation of the facultative methanotroph Methylocella silvestris BL2
- Author
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Andrew, Crombie and J Colin, Murrell
- Subjects
Recombination, Genetic ,Electroporation ,Beijerinckiaceae ,DNA ,Genetic Engineering ,Isocitrate Lyase ,Methane ,Gene Deletion - Abstract
An understanding of the metabolism and metabolic regulation of the facultative methanotroph Methylocella silvestris BL2 is required to understand its role in methane oxidation in the environment, and methods for genetics manipulation are essential tools in these investigations. In addition, the ability to engineer the metabolic capabilities of M. silvestris may well have useful biotechnological applications. We describe a simple and effective method of genetic manipulation for this organism which relies on the electroporation of a linear DNA fragment to introduce chromosomal gene deletions. In a two-step procedure, the gene of interest is first replaced with an antibiotic-resistance cassette which is subsequently removed, resulting in an unmarked gene deletion. This method is illustrated by the deletion of isocitrate lyase, which abolished growth on one-carbon and severely disabled growth on two-carbon compounds. Subsequent complementation with the wild-type gene and promoter restored growth, demonstrating stable transcription from the broad-host-range plasmid employed.
- Published
- 2011
29. Reproducibility of a microbial river water community to self-organize upon perturbation with the natural chemical enantiomers, R- and S-carvone
- Author
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Katja, Lehmann, Andrew, Crombie, and Andrew C, Singer
- Subjects
Biodegradation, Environmental ,Bacteria ,Rivers ,Monoterpenes ,Animals ,Eukaryota ,Reproducibility of Results ,Cyclohexane Monoterpenes ,Polymerase Chain Reaction ,Ecosystem - Abstract
A river water microbial community was studied in response to perturbation with the monoterpene enantiomers R- and S-carvone. The microbial community structure and function was also evaluated after enantiomers exposure was switched. Microbial communities were evaluated by length heterogeneity PCR. The addition of R- and S-carvone enriched for a range of functionally different communities: enantiomer-selective, racemic and ones that contain both. After 5 days incubation, the R- and S-carvone treatments developed a range of dominant microbial communities, which were increasingly dissimilar from the ones in which no carvone degradation had taken place (R-values: R-carvone 0.743, S-carvone 0.5007). There was an increase in the evenness of the microbial community structure upon carvone depletion. After the cross-over, the rate of carvone utilization was significantly faster than after the first carvone addition (P=0.008) as demonstrated by concomitant carvone and oxygen depletion. The main R-degrading community (450-456 bp) appeared enantioselective and largely unable to degrade S-carvone, whereas the S-carvone-degrading community (502-508 bp) appeared to have racemic catabolic capacity. In conclusion, chemical perturbations, such as enantiomers, might generate a significant shift in the river microbial ecology that can have implications for the function of a river in both a spatial and temporal context.
- Published
- 2008
30. The Geology of the Island of Arran
- Author
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Ramsay, Andrew Crombie, primary
- Published
- 2011
- Full Text
- View/download PDF
31. A Comparison of Labeling and Label-Free Mass Spectrometry-Based Proteomics Approaches.
- Author
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Vibhuti J. Patel, Konstantinos Thalassinos, Susan E. Slade, Joanne B. Connolly, Andrew Crombie, J. Colin Murrell, and James H. Scrivens
- Published
- 2009
- Full Text
- View/download PDF
32. II. On the comparative value of certain geological ages (or groups of formations) considered as items of geological time
- Author
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Andrew Crombie Ramsay
- Subjects
Geography ,Geologic time scale ,Mining engineering ,Earth science ,General Economics, Econometrics and Finance ,Value (mathematics) - Abstract
The author first reviews briefly several methods by which attempts have been made to estimate the value of minor portions of geological time, such as:—calculations intended to estimate the age of deltas, founded on the annual rate of accumulation of sediments; the astronomical method followed by Mr. Croll, in connexion with the recurrence of glacial epochs; the relative thicknesses of different formations; and the relation of strong unconformity between two sets of formations in connexion with marked disappearance of old genera and species, and the appearance of newer forms. Having shown that none of these methods give any clear help in the absolute measurement of time in years or cycles of years, even when founded on well-established facts, he proceeds to attempt to estimate the comparative value of long portions of geological time, all of which are represented by important series of formations. The author then alludes to the subject of two papers by himself, given to the Geological Society in 1871, on the Red Rocks of England, in which he attempted to show that the Old Red Sandstone, Permian, and New Red series were all deposited in great inland lakes, fresh or salt; and this, taken in connexion with the wide-spreading terrestrial character of much of the Carboniferous series, showed that a great continental age prevailed over much of Europe and in some other regions, from the close of the Silurian epoch to the close of the Trias. He then endeavours to show the value of the time occupied in the deposition of the above-named formations, when compared with the time occupied in the deposition of the Cambrian and Silurian strata, and of the marine and freshwater strata which were deposited between the close of the Triassic epoch and the present day.
- Published
- 1874
33. On the glacial origin of certain lakes in Switzerland, the Black Forest, Great Britain, Sweden, North America, and elsewhere
- Author
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Andrew Crombie Ramsay
- Subjects
geography ,geography.geographical_feature_category ,Memoir ,Period (geology) ,General Earth and Planetary Sciences ,Glacier ,Glacial period ,Black forest ,Debris ,Archaeology ,Iceberg - Abstract
Erroneous Theories of the Transport of Alpine Blocks .—In the year 1859, in a series of papers by the members of the Alpine Club, I published a memoir in which I compared the old glaciers of North Wales with those of Switzerland; and in it, among other matters, I explained the glacial origin of certain rock-basins now holding lakes, on the watersheds and in the old glacier-valleys of both those countries; and in a later edition of the same memoir, published as a separate book, with additions, I extended these generalizations to many of the lakes in Sutherlandshire. In the same work I also expressed an opinion that the blocks of Monthey, in the valley of the Rhone, and the great erratic boulders that strew the southern flank of the Jura had been transported by icebergs derived from glaciers which descended in the Alpine valleys to the sea-level, during a period of submergence in which the low country that lies between the Jura and the Oberland was covered with erratic drift. There was nothing new in this latter opinion, for it had previously been held by several distinguished geologists, both English and continental. Since then I have twice revisited Switzerland, and have seen good reason to change my opinion respecting the cause of the transport of erratic blocks to Monthey and the Jura, and of debris not remodelled by rivers, &c., that lies scattered over the lowlands of Switzerland, or that borders, or lies in great mounds well out in, the
- Published
- 1863
34. The physical geology and geography of Great Britain
- Author
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Ramsay, Andrew Crombie
- Abstract
by A. C. Ramsay, Handschriftliches Geschenkexlibris: "From the author" 002320250_0001 Exemplar der ETH-BIB, Geschenkexlibris-Etikette: "Legat von Herrn Professor Oswald Heer" 002320143_0002 Exemplar der ETH-BIB
- Published
- 1871
- Full Text
- View/download PDF
35. Isolation and semi-synthesis of enterocin analogues as novel antibiotics
- Author
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Michael Cowled, Daniel Vuong, Andrew Crombie, Peter Karuso, Ernest Lacey, and Andrew Piggott
36. Physique et physique du globe : divers mémoires de MM. Tyndall, Carpenter, Ramsay, Raphaël de Rossi et Félix Plateau / traduit par M. l'abbé Moigno
- Author
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Moigno, François (1804-1884). Traducteur, Tyndall, John (1820-1893). Auteur du texte, Carpenter, William Benjamin (1813-1885). Auteur du texte, Ramsay, Andrew Crombie (1814-1891). Auteur du texte, Rossi, Michele Stefano de (1834-1898). Auteur du texte, Plateau, Félix (1841-1911). Auteur du texte, Moigno, François (1804-1884). Traducteur, Tyndall, John (1820-1893). Auteur du texte, Carpenter, William Benjamin (1813-1885). Auteur du texte, Ramsay, Andrew Crombie (1814-1891). Auteur du texte, Rossi, Michele Stefano de (1834-1898). Auteur du texte, and Plateau, Félix (1841-1911). Auteur du texte
- Abstract
Collection : Actualités scientifiques ; n° 43, Contient une table des matières, Avec mode texte
37. Physique et physique du globe : divers mémoires de MM. Tyndall, Carpenter, Ramsay, Raphaël de Rossi et Félix Plateau / traduit par M. l'abbé Moigno
- Author
-
Moigno, François (1804-1884). Traducteur, Tyndall, John (1820-1893). Auteur du texte, Carpenter, William Benjamin (1813-1885). Auteur du texte, Ramsay, Andrew Crombie (1814-1891). Auteur du texte, Rossi, Michele Stefano de (1834-1898). Auteur du texte, Plateau, Félix (1841-1911). Auteur du texte, Moigno, François (1804-1884). Traducteur, Tyndall, John (1820-1893). Auteur du texte, Carpenter, William Benjamin (1813-1885). Auteur du texte, Ramsay, Andrew Crombie (1814-1891). Auteur du texte, Rossi, Michele Stefano de (1834-1898). Auteur du texte, and Plateau, Félix (1841-1911). Auteur du texte
- Abstract
Collection : Actualités scientifiques : première série ; n° 43, Collection : Actualités scientifiques ; n° 43, Contient une table des matières, Avec mode texte
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