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Most dinosaurs had scales, not feathers, fossil analysis concludes

Most dinosaurs had scales, not feathers, fossil analysis concludes | LGN | Scoop.it

Despite recent theories suggesting a common feathered ancestor or proto-feathers on all dinosaurs, new survey confirms that scales were the norm.


Researchers have called time on a growing suspicion that many dinosaurs were not the dry, scaly animals of popular conception, but fluffy, feathered beasts instead. Remains unearthed in recent years have revealed feathers or proto-feathers on a range of dinosaurs, leading some paleontologists to wonder if all of the animals evolved from a feathered ancestor and sported some kind of plumage themselves.


But while many meat-eating theropods, such as velociraptors and relatives of tyrannosaurs, were clearly clad in feathers, a fresh analysis of prehistoric remains suggests that most dinosaurs were scaly beasts after all.


Nicolás Campione, a dinosaur researcher at Uppsala University in Sweden, worked with scientists at the Natural History Museum in London and the Royal Ontario Museum in Toronto to survey some of the best-preserved dinosaur fossils from museums around the world. 


The scientists collected information on around 75 species that are known from the fossil remains of their soft tissues to have had either scales or feathers. From these, they created a dinosaur family tree and used a statistical model to work out the odds of species having feathers at different points in dinosaur history.


“What we found from this analysis is that the first dinosaur was probably not feathered,” said Campione. “Feathers clearly evolved in the dinosaur lineage, but right now, the data do not point to a feathered ancestor for them all.”


The first dinosaurs evolved from reptiles more than 230 million years ago. Feathers are thought to have arisen more than once in dinosaur lineages, and while they live on and give flight to modern birds, feathers first emerged for other reasons: for warmth or to provide colorful plumage displays.


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Spithioneines A and B, Two New Bohemamine Derivatives Possessing Ergothioneine Moiety from a Marine-Derived Streptomyces spinoverrucosus

Spithioneines A and B, Two New Bohemamine Derivatives Possessing Ergothioneine Moiety from a Marine-Derived Streptomyces spinoverrucosus | LGN | Scoop.it
Spithioneines A and B (1 and 2), two new bohemamine-type pyrrolizidine alkaloids possessing an unusual ergothioneine moiety, were isolated from a marine-derived Streptomyces spinoverrucosus. Their structures were elucidated by spectroscopic analysis, CD spectra, and chemical degradation and synthesis. Compounds 1 and 2 are rare natural products that incorporate the amino acid ergothioneine.

 

Peng Fu and John B. MacMillan Org. Lett., Article ASAPDOI: 10.1021/acs.orglett.5b01328
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Nazumazoles A–C, Cyclic Pentapeptides Dimerized through a Disulfide Bond from the Marine Sponge Theonella swinhoei

Nazumazoles A–C, Cyclic Pentapeptides Dimerized through a Disulfide Bond from the Marine Sponge Theonella swinhoei | LGN | Scoop.it

A mixture of nazumazoles A–C (1–3) was purified from the extract of the marine spongeTheonella swinhoei. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation of the NMR data and chemical degradations. Nazumazoles contain one residue each of alanine-derived oxazole and α-keto-β-amino acid residue. Nazumazoles exhibited cytotoxicity against P388 cells.


Kazuya Fukuhara , Kentaro Takada *, Shigeru Okada , and Shigeki MatsunagaOrg. Lett., Article ASAPDOI: 10.1021/acs.orglett.5b01020



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Dinosaurs wiped out rapidly 66 million years ago

Dinosaurs wiped out rapidly 66 million years ago | LGN | Scoop.it

Dinosaurs flourished in Europe right up until the asteroid impact that wiped them out 66 million years ago, a new study shows. The theory that an asteroid rapidly killed off the dinosaurs is widely recognized, but until recently dinosaur fossils from the latest Cretaceous--the final stanza of dinosaur evolution--were known almost exclusively from North America. This has raised questions about whether the sudden decline of dinosaurs in the American and Canadian west was merely a local story.


The new study synthesizes a flurry of research on European dinosaurs over the past two decades. Fossils of latest Cretaceous dinosaurs are now commonly discovered in Spain, France, Romania, and other countries. By looking at the variety and ages of these fossils, a team of researchers led by Zoltán Csiki-Sava of the University of Bucharest'sFaculty of Geology and Geophysics has determined that dinosaurs remained diverse in European ecosystems very late into the Cretaceous.


In the Pyrenees of Spain and France, the best area in Europe for finding latest Cretaceous dinosaurs, meat and plant-eating species are present and seemingly flourishing during the final few hundred thousand years before the asteroid hit.


Dr Csiki-Sava said "For a long time, Europe was overshadowed by other continents when the understanding of the nature, composition and evolution of latest Cretaceous continental ecosystems was concerned. The last 25 years witnessed a huge effort across all Europe to improve our knowledge, and now we are on the brink of fathoming the significance of these new discoveries, and of the strange and new story they tell about life at the end of the Dinosaur Era."


Dr Steve Brusatte of the University of Edinburgh's School of GeoSciences (UK), an author on the report, added: "Everyone knows that an asteroid hit 66 million years ago and dinosaurs disappeared, but this story is mostly based on fossils from one part of the world, North America. We now know that European dinosaurs were thriving up to the asteroid impact, just like in North America. This is strong evidence that the asteroid really did kill off dinosaurs in their prime, all over the world at once."


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Horsetails Are Ancient Polyploids: Evidence from Equisetum giganteum

Horsetails Are Ancient Polyploids: Evidence from Equisetum giganteum | LGN | Scoop.it

Can you look at Equisetum without thinking "dinosaurs!"? A new study explores the molecular basis for their persistence (and it involves whole genome duplication - more genes good). http://www.plantcell.org/…/early/2015/05/22/tpc.15.00157.ab…; and summary http://www.plantcell.org/conte…/early/2015/…/22/tpc.15.00409


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Natural products in soil microbe interactions and evolution - Natural Product Reports (RSC Publishing)

Natural products in soil microbe interactions and evolution - Natural Product Reports (RSC Publishing) | LGN | Scoop.it

In recent years, bacterial interspecies interactions mediated by small molecule natural products have been found to give rise to a surprising array of phenotypes in soil-dwelling bacteria, especially among Streptomyces and Bacillus species. This review examines these interspecies interactions, and the natural products involved, as they have been presented in literature stemming from four disciplines: soil science, interspecies microbiology, ecology, and evolutionary biology. We also consider how these interactions fit into accepted paradigms of signaling, cueing, and coercion.


Matthew F. Traxlerb and   Roberto Kolter*a  Show AffiliationsNat. Prod. Rep., 2015, Advance Article


DOI: 10.1039/C5NP00013K


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Conformation–activity relationships of polyketide natural products

Conformation–activity relationships of polyketide natural products | LGN | Scoop.it
Polyketides represent an important class of secondary metabolites that interact with biological targets connected to a variety of disease-associated pathways. Remarkably, nature's assembly lines, polyketide synthases, manufacture these privileged structures through a combinatorial mixture of just a few structural units. This review highlights the role of these structural elements in shaping a polyketide's conformational preferences, the use of computer-based molecular modeling and solution NMR studies in the identification of low-energy conformers, and the importance of conformational analogues in probing the bound conformation. In particular, this review covers several examples wherein conformational analysis complements classic structure–activity relationships in the design of biologically active natural product analogues.

 

Erik M. Larsen,a   Matthew R. Wilsona and   Richard E. Taylor*a   Show AffiliationsNat. Prod. Rep., 2015, Advance Article


DOI: 10.1039/C5NP00014A


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Antiviral Activity of Flexibilane and Tigliane Diterpenoids from Stillingia lineata

Antiviral Activity of Flexibilane and Tigliane Diterpenoids from Stillingia lineata | LGN | Scoop.it

n an effort to identify new potent and selective inhibitors of chikungunya virus and HIV-1 and HIV-2 virus replication, the endemic Mascarene species Stillingia lineata was investigated. LC/MS and bioassay-guided purification of the EtOAc leaf extract using a chikungunya virus-cell-based assay led to the isolation of six new (4–9) and three known (1–3) tonantzitlolones possessing the rare C20-flexibilane skeleton, along with tonantzitloic acid (10), a new linear diterpenoid, and three new (11, 13, and 15) and two known (12 and 14) tigliane-type diterpenoids. The planar structures of the new compounds and their relative configurations were determined by spectroscopic analysis, and their absolute configurations were determined through comparison with literature data and from biogenetic considerations. These compounds were investigated for selective antiviral activity against chikungunya virus (CHIKV), Semliki Forest virus, Sindbis virus, and, for compounds 11–15, the HIV-1 and HIV-2 viruses. Compounds 12–15 were found to be the most potent and are selective inhibitors of CHIKV, HIV-1, and HIV-2 replication. In particular, compound 14 inhibited CHIKV replication with an EC50 value of 1.2 μM on CHIKV and a selectivity index of >240, while compound 15 inhibited HIV-1 and HIV-2 with EC50 values of 0.043 and 0.018 μM, respectively. It was demonstrated further that potency and selectivity are sensitive to the substitution pattern on the tigliane skeleton. The cytotoxic activities of compounds 1–10 were evaluated against the HCT-116, MCF-7, and PC3 cancer cell lines.

 

Florent Olivon†, Héliciane Palenzuela†, Emmanuelle Girard-Valenciennes‡, Johan Neyts§, Christophe Pannecouque§, Fanny Roussi†, Isabelle Grondin‡, Pieter Leyssen§, and Marc LitaudonJ. Nat. Prod., Article ASAPDOI: 10.1021/acs.jnatprod.5b00116
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Free Technology for Teachers: 20 Good Map Creation Tools for Students ~ by Richard Byrne

Free Technology for Teachers: 20 Good Map Creation Tools for Students ~ by Richard Byrne | LGN | Scoop.it
A couple of years ago I published a list of 21 online map creation tools. Since then some of those tools have gone offline and new tools have replaced them. Here's my updated list of online map creation tools for students and teachers.

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Aplysiasecosterol A: A 9,11-Secosteroid with an Unprecedented Tricyclic γ-Diketone Structure from the Sea Hare Aplysia kurodai

Aplysiasecosterol A: A 9,11-Secosteroid with an Unprecedented Tricyclic γ-Diketone Structure from the Sea Hare Aplysia kurodai | LGN | Scoop.it

A new 9,11-secosteroid having an unprecedented tricyclic γ-diketone structure, aplysiasecosterol A (1), was isolated from the sea hareAplysia kurodai. The structure was determined by one- and two-dimensional NMR spectroscopic analysis, molecular modeling studies, a comparison of experimental and calculated ECD spectra, and a modified Mosher′s method. Aplysiasecosterol A (1) exhibited cytotoxicity against human myelocytic leukemia HL-60 cells. A biosynthetic pathway for 1 from a known cholesterol was proposed and includes twice α-ketol rearrangements and an intramolecular acetalization.


Angewandte Chemie International EditionAtsushi Kawamura, 

Prof. Dr. Masaki Kita*andProf. Dr. Hideo Kigoshi*

Article first published online: 29 APR 2015

DOI: 10.1002/anie.201501749



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Researchers Create Lens to Turn Smartphone into Microscope - for 3 Cents

Researchers Create Lens to Turn Smartphone into Microscope - for 3 Cents | LGN | Scoop.it

Researchers at the University of Houston have created an optical lens that can be placed on an inexpensive smartphone to amplify images by a magnitude of 120, all for just 3 cents a lens. Wei-Chuan Shih, assistant professor of electrical and computer engineering at UH, said the lens can work as a microscope, and the cost and ease of using it – it attaches directly to a smartphone camera lens, without the use of any additional device – make it ideal for use with younger students in the classroom. It also could have clinical applications, allowing small or isolated clinics to share images with specialists located elsewhere, he said.


In a paper published in the Journal of Biomedical Optics, Shih and three graduate students describe how they produced the lenses and examine the image quality. Yu-Lung Sung, a doctoral candidate, served as first author; others involved in the study include Jenn Jeang, who will start graduate school at Liberty University in Virginia this fall, and Chia-Hsiung Lee, a former graduate student at UH now working in the technology industry in Taiwan.


The lens is made of polydimethylsiloxane (PDMS), a polymer with the consistency of honey, dropped precisely on a preheated surface to cure. Lens curvature – and therefore, magnification – depends on how long and at what temperature the PDMS is heated, Sung said.

The resulting lenses are flexible, similar to a soft contact lens, although they are thicker and slightly smaller.


“Our lens can transform a smartphone camera into a microscope by simply attaching the lens without any supporting attachments or mechanism,” the researchers wrote. “The strong, yet non-permanent adhesion between PDMS and glass allows the lens to be easily detached after use. An imaging resolution of 1 (micrometer) with an optical magnification of 120X has been achieved.”


Conventional lenses are produced by mechanical polishing or injection molding of materials such as glass or plastics. Liquid lenses are available, too, but those that aren’t cured require special housing to remain stable. Other types of liquid lenses require an additional device to adhere to the smartphone.


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MATsolutions's curator insight, May 5, 2015 1:22 PM

Researchers at the University of Houston have developed cheap lenses that can turn a smartphone into a microscope. The lenses, which can be made for as little as three cents a piece, amplify images by a magnitude of 120. The lenses attach to smartphones without any supporting mechanisms, and can easily be removed when necessary. 

Primary applications for these lenses are educational - researchers say students can use them as microscopes, sharing images easily by text message. The low cost of production means that if they are broken, replacements will also be cheap. The graduate students at UH have started a crowdfunding campaign to fund the development of these lenses in bulk, and you can donate on Indiegogo to help their cause. 

Diane Johnson's curator insight, May 6, 2015 9:50 AM

Wow! How handy is this!

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How to end hunger: lessons from the father of India’s green revolution

How to end hunger: lessons from the father of India’s green revolution | LGN | Scoop.it
The research of MS Swaminathan led to India reaching agricultural self-sufficiency in the 1970s. He reflects on scientists’ role in feeding the world

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Mary Williams's curator insight, May 2, 2015 3:00 AM

Good article by Professor MS Swaminathan in the Guardian - notable quote, "Chronic hunger does not move the media". It's true and lies at the root of a lot of problems! Wealthy, well-fed individuals need to care as deeply about the world's hungry as they do the latest celebrity....

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Secondary metabolites in plant innate immunity

Secondary metabolites in plant innate immunity | LGN | Scoop.it
Plant secondary metabolites carry out numerous functions in interactions between plants and a broad range of other organisms. Experimental evidence strongly supports the indispensable contribution of many constitutive and pathogen-inducible phytochemicals to plant innate immunity. Extensive studies on model plant species, particularly Arabidopsis thaliana, have brought significant advances in our understanding of the molecular mechanisms underpinning pathogen-triggered biosynthesis and activation of defensive secondary metabolites. However, despite the proven significance of secondary metabolites in plant response to pathogenic microorganisms, little is known about the precise mechanisms underlying their contribution to plant immunity. This insufficiency concerns information on the dynamics of cellular and subcellular localization of defensive phytochemicals during the encounters with microbial pathogens and precise knowledge on their mode of action. As many secondary metabolites are characterized by their in vitro antimicrobial activity, these compounds were commonly considered to function in plant defense as in planta antibiotics. Strikingly, recent experimental evidence suggests that at least some of these compounds alternatively may be involved in controlling several immune responses that are evolutionarily conserved in the plant kingdom, including callose deposition and programmed cell death.

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Chemical ecology of fungi - Natural Product Reports

Chemical ecology of fungi - Natural Product Reports | LGN | Scoop.it

Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.


Peter Spiteller*a  Show AffiliationsNat. Prod. Rep., 2015, Advance Article


DOI: 10.1039/C4NP00166D



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Eric Larson's curator insight, June 3, 2015 8:43 AM

What can fungi do for us?

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Terfestatins B and C, New p-Terphenyl Glycosides Produced by Streptomyces sp. RM-5–8

Terfestatins B and C, New p-Terphenyl Glycosides Produced by Streptomyces sp. RM-5–8 | LGN | Scoop.it

Terfestatins B (1) and C (2), new p-terphenyls bearing a novel unsaturated hexuronic acid (4-deoxy-α-l-threo-hex-4-enopyranuronate), a unique β-d-glycosyl ester of 5-isoprenylindole-3-carboxylate (3) and the same rare sugar, and two new hygromycin precursors, were characterized as metabolites of the coal mine fire isolate Streptomyces sp. RM-5–8. EtOH damage neuroprotection assays using rat hippocampal-derived primary cell cultures with 1, 2, 3and echoside B (a terfestatin C-3′-β-d-glucuronide from Streptomyces sp. RM-5–8) revealed 1as potently neuroprotective, highlighting a new potential application of the terfestatin scaffold.


Xiachang Wang †‡, Anna R. Reynolds §, Sherif I. Elshahawi †‡, Khaled A. Shaaban †‡, Larissa V. Ponomareva †‡, Meredith A. Saunders §, Ibrahim S. Elgumati §, Yinan Zhang †‡, Gregory C. Copley ∥,James C. Hower ∥, Manjula Sunkara ⊥, Andrew J. Morris ⊥, Madan K. Kharel #, Steven G. Van Lanen‡, Mark A. Prendergast §, and Jon S. Thorson *†‡Org. Lett., Article ASAPDOI: 10.1021/acs.orglett.5b01203



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Biological activity of natural sesquiterpenoids containing a gem-dimethylcyclopropane unit

Biological activity of natural sesquiterpenoids containing a gem-dimethylcyclopropane unit | LGN | Scoop.it
Covering: 1963 up to the end of 2014The biological activities of aristolane, aromadendrane, ent-1,10-secoaromadendrane, 2,3-secoaromadendrane, ent-5,10-cycloaromadendrane, bicyclogermacrene, lepidozane, and maaliane terpenoids which contain the gem-dimethylcyclopropyl unit are described. Particular attention is giv

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Biodegradable computer chips made from wood

Biodegradable computer chips made from wood | LGN | Scoop.it

Portable electronics -- typically made of non-renewable, non-biodegradable and potentially toxic materials -- are discarded at an alarming rate in consumers' pursuit of the next best electronic gadget.


In an effort to alleviate the environmental burden of electronic devices, a team of University of Wisconsin-Madison researchers has collaborated with researchers in the Madison-based U.S. Department of Agriculture Forest Products Laboratory (FPL) to develop a surprising solution: a semiconductor chip made almost entirely of wood.


The research team, led by UW-Madison electrical and computer engineering professor Zhenqiang "Jack" Ma, described the new device in a paper published today (May 26, 2015) by the journal Nature Communications. The paper demonstrates the feasibility of replacing the substrate, or support layer, of a computer chip, with cellulose nanofibril (CNF), a flexible, biodegradable material made from wood.


"The majority of material in a chip is support. We only use less than a couple of micrometers for everything else," Ma says. "Now the chips are so safe you can put them in the forest and fungus will degrade it. They become as safe as fertilizer." Zhiyong Cai, project leader for an engineering composite science research group at FPL, has been developing sustainable nanomaterials since 2009.


"If you take a big tree and cut it down to the individual fiber, the most common product is paper. The dimension of the fiber is in the micron stage," Cai says. "But what if we could break it down further to the nano scale? At that scale you can make this material, very strong and transparent CNF paper."


Working with Shaoqin "Sarah" Gong, a UW-Madison professor of biomedical engineering, Cai's group addressed two key barriers to using wood-derived materials in an electronics setting: surface smoothness and thermal expansion.


"You don't want it to expand or shrink too much. Wood is a natural hydroscopic material and could attract moisture from the air and expand," Cai says. "With an epoxy coating on the surface of the CNF, we solved both the surface smoothness and the moisture barrier."

Gong and her students also have been studying bio-based polymers for more than a decade. CNF offers many benefits over current chip substrates, she says.


"The advantage of CNF over other polymers is that it's a bio-based material and most other polymers are petroleum-based polymers. Bio-based materials are sustainable, bio-compatible and biodegradable," Gong says. "And, compared to other polymers, CNF actually has a relatively low thermal expansion coefficient."


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Antiviral Activity of Diterpene Esters on Chikungunya Virus and HIV Replication

Antiviral Activity of Diterpene Esters on Chikungunya Virus and HIV Replication | LGN | Scoop.it

Recently, new daphnane, tigliane, and jatrophane diterpenoids have been isolated from various Euphorbiaceae species, of which some have been shown to be potent inhibitors of chikungunya virus (CHIKV) replication. To further explore this type of compound, the antiviral activity of a series of 29 commercially available natural diterpenoids was evaluated. Phorbol-12,13-didecanoate (11) proved to be the most potent inhibitor, with an EC50 value of 6.0 ± 0.9 nM and a selectivity index (SI) of 686, which is in line with the previously reported anti-CHIKV potency for the structurally related 12-O-tetradecanoylphorbol-13-acetate (13). Most of the other compounds exhibited low to moderate activity, including an ingenane-type diterpene ester, compound 28, with an EC50 value of 1.2 ± 0.1 μM and SI = 6.4. Diterpene compounds are known also to inhibit HIV replication, so the antiviral activities of compounds 1–29 were evaluated also against HIV-1 and HIV-2. Tigliane- (4β-hydroxyphorbol analogues 10, 11, 13,15, 16, and 18) and ingenane-type (27 and 28) diterpene esters were shown to inhibit HIV replication in vitro at the nanomolar level. A Pearson analysis performed with the anti-CHIKV and anti-HIV data sets demonstrated a linear relationship, which supported the hypothesis made that PKC may be an important target in CHIKV replication.


Louis-Félix Nothias-Scaglia †‡, Christophe Pannecouque §, Franck Renucci †, Leen Delang §, Johan Neyts §, Fanny Roussi ‡, Jean Costa †, Pieter Leyssen §, Marc Litaudon *‡, and Julien Paolini J. Nat. Prod., Article ASAPDOI: 10.1021/acs.jnatprod.5b00073Publication Date (Web): May 13, 2015





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Sigillin A, a unique polychlorinated arthropod deterrent from the snow flea Ceratophysella sigillata

Sigillin A, a unique polychlorinated arthropod deterrent from the snow flea Ceratophysella sigillata | LGN | Scoop.it

Sigillin A showed high repellent activity in a bioassay with predatory ants. A promising approach for the total synthesis of members of this new class of natural compounds was also developed. Ceratophysella sigillata, a winter-active species of springtail, produces unique polychlorinated octahydroisocoumarins to repel predators. The structure of the major compound, sigillin A, was elucidated through isolation, spectroscopic analysis, and X-ray crystall

Inedible: The snow flea Ceratophysella sigillata produces unique polychlorinated octahydroisocoumarins to repel predators. The structure of the major representative, sigillin A, was elucidated through isolation, spectroscopic analysis, and X-ray crystallography. A promising synthetic approach for the total synthesis of this class of compounds was developed, in which α-vinylation of a lactone and ring-closing metathesis are they key steps. (Photo F. Kohl)

 

Dr. Witali Schmidt1, Dr. Thies M. Schulze1,Dr. Gregor Brasse1, Dr. Edyta Nagrodzka1,Michael Maczka1, Prof. Dr. Jürg Zettel3,Prof. Dr. Peter G. Jones2, Prof. Dr. Jörg Grunenberg1, Prof. Dr. Monika Hilker4, Ute Trauer-Kizilelma4, Ute Braun4 andProf. Dr. Stefan Schulz1,*

Article first published online: 12 MAY 2015

DOI: 10.1002/anie.201501719

 

Angewandte Chemie International Edition

 

 


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Free Technology for Teachers: Analyze My Writing - Way More Than Word Clouds ~ by Richard Byrne

Free Technology for Teachers: Analyze My Writing - Way More Than Word Clouds ~ by Richard Byrne | LGN | Scoop.it
Paste your text into Analyze My Writing and it will generate a ton of information about your writing. Analyze My Writing will give you a break-down of the readability of your writing on five indices. The analysis will include listings of the most common words and most common word pairs in your writing. A listing of how frequently you use punctuation and punctuation types is included in the analysis provided by Analyze My Writing. Finally, a word cloud is included at the end of the analysis of your writing.

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Charles Newton's curator insight, May 14, 2015 4:02 PM

Tried this - very illuminating!

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Fresh evidence for how water reached Earth found in asteroid debris

Fresh evidence for how water reached Earth found in asteroid debris | LGN | Scoop.it

Water delivery via asteroids or comets is likely taking place in many other planetary systems, just as it happened on Earth, new research strongly suggests. Published by the Royal Astronomical Society and led by the University of Warwick, the research finds evidence for numerous planetary bodies, including asteroids and comets, containing large amounts of water.


The research findings add further support to the possibility water can be delivered to Earth-like planets via such bodies to create a suitable environment for the formation of life. Commenting on the findings lead researcher Dr Roberto Raddi, of the University of Warwick's Astronomy and Astrophysics Group, said: "Our research has found that, rather than being unique, water-rich asteroids similar to those found in our Solar System appear to be frequent. Accordingly, many planets may have contained a volume of water, comparable to that contained in the Earth.


"It is believed that the Earth was initially dry, but our research strongly supports the view that the oceans we have today were created as a result of impacts by water-rich comets or asteroids."


In observations obtained at the William Herschel Telescope in the Canary Islands, the University of Warwick astronomers detected a large quantity of hydrogen and oxygen in the atmosphere of a white dwarf (known as SDSS J1242+5226). The quantities found provide the evidence that a water-rich exo-asteroid was disrupted and eventually delivered the water it contained onto the star.


The asteroid, the researchers discovered, was comparable in size to Ceres -- at 900km across, the largest asteroid in the Solar System. "The amount of water found SDSS J1242+5226 is equivalent to 30-35% of the oceans on Earth," explained Dr Raddi.


The impact of water-rich asteroids or comets onto a planet or white dwarf results in the mixing of hydrogen and oxygen into the atmosphere. Both elements were detected in large amounts in SDSS J1242+5226.


Research co-author Professor Boris Gänsicke, also of University of Warwick, explained: "Oxygen, which is a relatively heavy element, will sink deep down over time, and hence a while after the disruption event is over, it will no longer be visible. "In contrast, hydrogen is the lightest element; it will always remain floating near the surface of the white dwarf where it can easily be detected. There are many white dwarfs that hold large amounts of hydrogen in their atmospheres, and this new study suggests that this is evidence that water-rich asteroids or comets are common around other stars than the Sun."


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Anti-parasitic Guanidine and Pyrimidine Alkaloids from the Marine Sponge Monanchora arbuscula

Anti-parasitic Guanidine and Pyrimidine Alkaloids from the Marine Sponge Monanchora arbuscula | LGN | Scoop.it
HPLC-UV-ELSD-MS-guided fractionation of the anti-parasitic extract obtained from the marine sponge Monanchora arbuscula, collected off the southeastern coast of Brazil, led to the isolation of a series of guanidine and pyrimidine alkaloids. The pyrimidines monalidine A (1) and arbusculidine A (7), as well as the guanidine alkaloids batzellamide A (8) and hemibatzelladines 9–11, represent new minor constituents that were identified by analysis of spectroscopic data. The total synthesis of monalidine A confirmed its structure. Arbusculidine A (7), related to the ptilocaulin/mirabilin/netamine family of tricyclic guanidine alkaloids, is the first in this family to possess a benzene ring. Batzellamide A (8) and hemibatzelladines 9–11 represent new carbon skeletons that are related to the batzelladines. Evaluation of the anti-parasitic activity of the major known metabolites, batzelladines D (12), F (13), L (14), and nor-L (15), as well as of synthetic monalidine A (1), against Trypanosoma cruzi and Leishmania infantum is also reported, along with a detailed investigation of parasite cell-death pathways promoted by batzelladine L (14) and norbatzelladine L (15).

 

Mario F. C. Santos†, Philip M. Harper‡, David E. Williams§, Juliana T. Mesquita⊥, Érika G. Pinto⊥∥, Thais A. da Costa-Silva⊥, Eduardo Hajdu#, Antonio G. Ferreira∇, Raquel A. Santos⊗, Patrick J. Murphy‡, Raymond J. Andersen§, Andre G. Tempone*⊥∥, and Roberto G. S. BerlinckJ. Nat. Prod., Article ASAPDOI: 10.1021/acs.jnatprod.5b00070
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Achievement of 1020 MHz NMR (JEOL)

Achievement of 1020 MHz NMR (JEOL) | LGN | Scoop.it
Kenjiro Hashia, , , Shinobu Ohkia, Shinji Matsumotoa, Gen Nishijimaa, Atsushi Gotoa, Kenzo Deguchia, Kazuhiko Yamadaa, 1, Takashi Noguchia, Shuji Sakaia, Masato Takahashib, Yoshinori Yanagisawab, Seiya Iguchib, c, Toshio Yamazakib, Hideaki Maedab, Ryoji Tanakad, Takahiro Nemotod,Hiroto Suematsud, Takashi Mikie, Kazuyoshi Saitoe, Tadashi ShimizuWe have successfully developed a 1020 MHz (24.0 T) NMR magnet, establishing the world’s highest magnetic field in high resolution NMR superconducting magnets. The magnet is a series connection of LTS (low-Tc superconductors NbTi and Nb3Sn) outer coils and an HTS (high-Tc superconductor, Bi-2223) innermost coil, being operated at superfluid liquid helium temperature such as around 1.8 K and in a driven-mode by an external DC power supply. The drift of the magnetic field was initially ± 0.8 ppm/10 h without the 2H lock operation; it was then stabilized to be less than 1 ppb/10 h by using an NMR internal lock operation. The full-width at half maximum of a 1H spectrum taken for 1 % CHCl3 in acetone-d6 was as low as 0.7 Hz (0.7 ppb), which was sufficient for solution NMR. On the contrary, the temporal field stability under the external lock operation for solid-state NMR was 170 ppb/10 h, sufficient for NMR measurements for quadrupolar nuclei such as 17O; a 17O NMR measurement for labeled tri-peptide clearly demonstrated the effect of high magnetic field on solid-state NMR spectra
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FAO food price index drops again in March driven by sugar's sharp slide

FAO food price index drops again in March driven by sugar's sharp slide | LGN | Scoop.it

The FAO Food Price Index continued to decline in March, dropping 1.5 percent from February and 18.7 percent (40 points) below its level a year earlier.


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Defensive symbioses of animals with prokaryotic and eukaryotic microorganisms

Defensive symbioses of animals with prokaryotic and eukaryotic microorganisms | LGN | Scoop.it

Many organisms team up with microbes for defense against predators, parasites, parasitoids, or pathogens. Here we review the described protective symbioses between animals (including marine invertebrates, nematodes, insects, and vertebrates) and bacteria, fungi, and dinoflagellates. We focus on associations where the microbial natural products mediating the protective activity have been elucidated or at least strong evidence for the role of symbiotic microbes in defense is available. In addition to providing an overview of the known defensive animal–microbe symbioses, we aim to derive general patterns on the chemistry, ecology, and evolution of such associations.

 

Laura V. Flórez,a   Peter H. W. Biedermann,a   Tobias Engla and  Martin Kaltenpoth*a   Show AffiliationsNat. Prod. Rep., 2015, Advance Article


DOI: 10.1039/C5NP00010F


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luis Quiros-Guerrero's curator insight, April 25, 2015 12:19 PM

interaction-symbioses... one really interesting source of new compounds