The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Matthew I. Gibson - One of the best experts on this subject based on the ideXlab platform.
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antifreeze protein mimetic metallohelices with potent ice recrystallization inhibition activity
Journal of the American Chemical Society, 2017Co-Authors: Daniel E Mitchell, Rebecca Ann Vipond, Guy J. Clarkson, Peter Scott, Matthew I. GibsonAbstract:Antifreeze proteins are produced by Extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure–property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.
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Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity
2017Co-Authors: Daniel E. Mitchell, Rebecca Ann Vipond, Peter Scott, Guy Clarkson, David J. Fox, Matthew I. GibsonAbstract:Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure–property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition
Daniel E Mitchell - One of the best experts on this subject based on the ideXlab platform.
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antifreeze protein mimetic metallohelices with potent ice recrystallization inhibition activity
Journal of the American Chemical Society, 2017Co-Authors: Daniel E Mitchell, Rebecca Ann Vipond, Guy J. Clarkson, Peter Scott, Matthew I. GibsonAbstract:Antifreeze proteins are produced by Extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure–property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.
Howell G M Edwards - One of the best experts on this subject based on the ideXlab platform.
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microorganism response to stressed terrestrial environments a raman spectroscopic perspective of extremophilic life strategies
Life, 2013Co-Authors: Susana E Jorgevillar, Howell G M EdwardsAbstract:Raman spectroscopy is a valuable analytical technique for the identification of biomolecules and minerals in natural samples, which involves little or minimal sample manipulation. In this paper, we evaluate the advantages and disadvantages of this technique applied to the study of Extremophiles. Furthermore, we provide a review of the results published, up to the present point in time, of the bio- and geo-strategies adopted by different types of Extremophile colonies of microorganisms. We also show the characteristic Raman signatures for the identification of pigments and minerals, which appear in those complex samples.
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a novel Extremophile strategy studied by raman spectroscopy
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2007Co-Authors: Howell G M EdwardsAbstract:Abstract A case is made for the classification of the colonisation by Dirina massiliensis forma sorediata of pigments on ancient wall-paintings as extremophilic behaviour. The lichen encrustations studied using FT-Raman spectroscopy have yielded important molecular information which has assisted in the identification of the survival strategy of the organism in the presence of significant levels of heavy metal toxins. The production of a carotenoid, probably astaxanthin, at the surface of the lichen thalli is identified from its characteristic biomolecular signatures in the Raman spectrum, whereas the presence of calcium oxalate dihydrate (weddellite) has been identified at both the upper and lower surfaces of the thalli and in core samples taken from depths of up to 10 mm through the encrustation into the rock substrate. The latter observation explains the significant disintegrative biodeteriorative effect of the colonisation upon the integrity of the wall-paintings and can be used to direct conservatorial and preservation efforts of the art work. A surprising result proved to be the absence of Raman spectroscopic evidence for the complexation of the metal pigments by the oxalic acid produced by the metabolic action of the organisms, unlike several cases that have been reported in the literature.
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raman spectroscopic analysis of cyanobacterial colonization of hydromagnesite a putative martian Extremophile
Icarus, 2005Co-Authors: Howell G M Edwards, Caroline D Moody, Emma M Newton, Susana Jorge E Villar, Michael J RussellAbstract:Abstract Raman spectra of an Extremophile cyanobacterial colony in hydromagnesite from Lake Salda in Turkey have revealed a biogeological modification which is manifest as aragonite in the stratum associated with the colony. The presence of key spectral biomarkers of organic protectant molecules such as β -carotene and scytonemin indicate that the survival strategy of the cyanobacteria is significantly one of UV-radiation protection. The terrestrial location of this Extremophile is worthy of consideration further because of its possible putative link with the “White Rock” formations in Sabaea Terra and Juventae Chasma on Mars.
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raman spectroscopic detection of key biomarkers of cyanobacteria and lichen symbiosis in extreme antarctic habitats evaluation for mars lander missions
Icarus, 2005Co-Authors: Howell G M Edwards, Caroline D Moody, Susana Jorge E Villar, David D WynnwilliamsAbstract:With proposals that micro-miniaturised Raman spectrometers could soon be part of a suite of analytical instrumentation on the surface of Mars, it is critically important to examine the spectral information that could be forthcoming from attempts to determine key molecular biosignatures under the hostile conditions of extra-terrestrial planetary exploration. Current approaches include the analysis of genuine martian geological material in the form of the SNC class meteorites, the formulation of simulated martian regoliths and the examination of putative martian terrestrial analogues; the latter provide the basis of this paper in the form of Antarctic Extremophile habitats. In particular, specimens of epilithic, chasmolithic and endolithic lichen and cyanobacterial colonies sampled along a progressively worsening transect towards a “limits of life” situation, beyond which survival of organisms becomes impossible, provide what is arguably the best terrestrial proving-ground for prototype Raman spectrometers for martian exploration. Here, we report the results of experiments on these extant Antarctic Extremophile colonies using a range of Raman excitation wavelengths and experimental conditions and also include a compilation of molecular spectral biosignatures, which may be considered as a suitable database for recognition of bioorganic modification of geological strata.
Ramla Sahli - One of the best experts on this subject based on the ideXlab platform.
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Biocontrol activity of effusol from the Extremophile plant, Juncus maritimus, against the wheat pathogen Zymoseptoria tritici
Environmental Science and Pollution Research, 2018Co-Authors: Ramla Sahli, Céline Rivière, Vincent Roumy, Thierry Hennebelle, Abderrazak Smaoui, Ali Siah, Jennifer Samaillie, Riadh Ksouri, Patrice Halama, Sevser SahpazAbstract:Zymoseptoria tritici , responsible for Septoria tritici blotch, is the most important pathogen of wheat. The control of this parasite relies mainly on synthetic fungicides, but their use is increasingly controversial and searching for alternative management strategies is encouraged. In this context, the biocontrol potential of crude methanolic extracts of eight Extremophile plant species from Tunisia, including three xerophytes and five halophytes, against Z. tritici was assessed. Only the extract of Juncus maritimus rhizomes showed significant in vitro antifungal activity . In Extremophile plants, the production of secondary metabolites is often influenced by abiotic conditions. Thus, we collected several samples of J. maritimus rhizomes at different vegetative stages, at different periods, and from different substrates to compare their antifungal activities. Our results suggest that the plant environment, especially the substrate of the soil, should be taken into account to identify great sources of natural antifungal products. From the most active sample, a 9,10-dehydrophenanthrene derivative, effusol, absent from other J. maritimus rhizomes extracts, was purified. This product showed a strong antifungal activity against the pathogen, with a minimal inhibitory concentration of 19 μg mL^−1 and an half-maximal inhibitory concentration of 9.98 μg mL^−1. This phenanthrene derivative could be a promising biocontrol molecule against Z . tritici .
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An ecological approach to discover new bioactive extracts and products: the case of Extremophile plants
Journal of Pharmacy and Pharmacology, 2017Co-Authors: Ramla Sahli, Céline Rivière, Marie-emmanuelle Sahuc, Claire Beaufay, Vincent Roumy, Thierry Hennebelle, Joanne Bero, Abderrazak Smaoui, Christel Neut, Yves RouilléAbstract:OBJECTIVES: Eight Extremophile plants from Tunisia were screened to find natural products with benefits in human health. METHODS: These plants were collected in different areas in Tunisia. Their methanolic extracts were evaluated for their total phenolic content and for their antiradical (DPPH), antimicrobial (on 35 bacteria and one yeast), antiviral (hepatitis C virus, HCV) and cytotoxic activity (against WI38 and J774 cell lines). The most active species were subjected to a bioguided fractionation. KEY FINDINGS: The screening revealed promising activity for four plants, but two species have both antiradical and antimicrobial activity: Juncus maritimus and Limonium virgatum. The rhizomes extract of J. maritimus showed the highest activity against HCV, a selective antibacterial activity against Streptococcus dysgalactiae, and a moderate antiradical activity which is due to luteolin isolated in one step by centrifugal partition chromatography. The stems' and leaves' extracts of L. virgatum were rich in polyphenols responsible for the antiradical activity. Also, Limonium extracts showed an antibacterial activity with a broad spectrum. CONCLUSIONS: Extremophile plants have proven to be a promising source for bioactive metabolites. They have a powerful antioxidant system highly influenced by biotic and abiotic factors and the ability to produce secondary metabolites with antimicrobial activity
Peter Scott - One of the best experts on this subject based on the ideXlab platform.
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antifreeze protein mimetic metallohelices with potent ice recrystallization inhibition activity
Journal of the American Chemical Society, 2017Co-Authors: Daniel E Mitchell, Rebecca Ann Vipond, Guy J. Clarkson, Peter Scott, Matthew I. GibsonAbstract:Antifreeze proteins are produced by Extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure–property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.
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Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity
2017Co-Authors: Daniel E. Mitchell, Rebecca Ann Vipond, Peter Scott, Guy Clarkson, David J. Fox, Matthew I. GibsonAbstract:Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure–property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition
