Author Archive

Protein sorting within cells

Iron oxide nanoparticles coated with glutathione (purple), which is anchored by dopamine (yellow) and binds to the protein

Iron oxide nanoparticles coated with glutathione (purple), which is anchored by dopamine (yellow) and binds to the protein

US scientists have used magnetic nanoparticles with specific ligands to latch on to and visualise specific proteins in living cells. The approach could be used to identify new, selective ligands that bind proteins, which may help uncover drug–target interactions inside cells, say the researchers. Also, using magnetic nanoparticles means that the distribution, orientation and aggregation of cellular proteins could be controlled, leading to new ways to control the fate of cells.

A deeper understanding of protein function inside cells is essential as scientists try to find new ways to diagnose and treat disease. The first challenge is to locate the proteins involved and find out what they are doing, which is not an easy feat, considering the abundance of different proteins in our cells.

Read the full article in Chemistry World

Link to journal article
Magnetic nanoparticles for direct protein sorting inside live cells
Yue Pan ,  Marcus J. C. Long ,  Hsin-Chieh Lin ,  Lizbeth Hedstrom and Bing Xu
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20519J

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New way to capture sulfur dioxide

Scientists in Germany and Canada have developed a new way to capture sulfur dioxide gas. It could minimise the environmental impact of the gas, which causes acid rain.

The team made a series of frustrated Lewis pairs (FLPs) consisting of a bulky phosphane Lewis base component and a boron Lewis acid component. The FLPs rapidly and efficiently trap sulfur dioxide by adding the phosphane component to sulfur and the boron to oxygen.

Link to journal article
Reactions of Phosphorus/Boron Frustrated Lewis Pairs with SO2
M Sajid et al
Chem. Sci., 2012, DOI: 10.1039/c2sc21161k

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Protein surface study to design new stealth compounds

The surface chemistry of proteins makes them stable in complex biological environments. Scientists in the US have investigated why to enable peptide-based materials that resist non-specific interactions (stealth compounds) to be designed.

The cytoplasm is a crowded environment containing lots of different molecules but proteins resist non-specific interactions with these molecules. Understanding and mimicking nature’s resistance to non-specific interactions is key to addressing emerging challenges in chemistry, especially in practical applications where complex environments can degrade materials and surface coatings.

Here, the team has used structural bioinformatics to study proteins and molecular chaperones, which guide proteins from a misfolded or unfolded conformation back into a native conformation. They found that nature uses sequence design to modulate non-specific interactions so that the proteins function properly. Specifically, lysine and glutamic acid are the most abundant amino acids on the surface of proteins.

Link to journal article
Decoding nonspecific interactions from nature
A D White et al
Chem. Sci., DOI: 10.1039/c2sc21135a

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New source of MRSA antibiotic

Scientists in the UK have demonstrated that bottromycin (an antibiotic that works against MRSA) is biosynthesised from a larger precursor ribosomal peptide. This was proposed following a genome mining analysis of Streptomyces scabies and confirmed by a series of gene deletion experiments. The work also identifies S. scabies as a previously unknown producer of bottromycin. An almost identical gene cluster was also identified in S. bottropensis, an established bottromycin producer. Bottromycin is the first ribosomal peptide natural product that derives from the N-terminus of a larger prepeptide and the first terrestrial peptide to be directly ethylated at beta-positions.

Bottromycin is active in vitro but unstable in vivo so if scientists can engineer its biosynthesis to make unnatural analogues they might be able to make good new antibiotics. By identifying this pathway the team should facilitate the generation of a library of bottromycin-like antibiotics.

Link to journal article
Identification and characterisation of the gene cluster for the anti-MRSA antibiotic bottromycin: Expanding the biosynthetic diversity of ribosomal peptides
W J K Crone, F J Leeper and A W Truman
Chem. Sci., 2012, DOI: 10.1039/c2sc21190d

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Top ten most accessed articles in July

This month sees the following articles in Chemical Science that are in the top ten most accessed:-

Copper-catalyzed decarboxylative C-N coupling for N-arylation
Yun Zhang, Sejal Patel and Nello Mainolfi
Chem. Sci.,
2012, Advance Article, DOI: 10.1039/C2SC20606D, Edge Article

Copper-catalyzed decarboxylative alkenylation of sp3 C-H bonds with cinnamic acids via a radical process
Zili Cui, Xiaojie Shang, Xiang-Feng Shao and Zhong-Quan Liu
Chem. Sci.,
2012, Advance Article, DOI: 10.1039/C2SC20712E, Edge Article

Chiral ionic Brønsted acid-achiral Brønsted base synergistic catalysis for asymmetric sulfa-Michael addition to nitroolefins
Daisuke Uraguchi, Natsuko Kinoshita, Daisuke Nakashima and Takashi Ooi
Chem. Sci.,
2012, Advance Article, DOI: 10.1039/C2SC20698F, Edge Article

A chemical synthesis of 11-methoxy mitragynine pseudoindoxyl featuring the interrupted Ugi reaction
Jimin Kim, John S. Schneekloth and Erik J. Sorensen
Chem. Sci.,
2012,3, 2849-2852, DOI: 10.1039/C2SC20669B, Edge Article

Methane: a new frontier in organometallic chemistry
Vincent N. Cavaliere and Daniel J. Mindiola
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20530K, Minireview

A fluorescent probe for rapid detection of hydrogen sulfide in blood plasma and brain tissues in mice
Yong Qian, Ling Zhang, Shuting Ding, Xin Deng, Chuan He, Xi Emily Zheng, Hai-Liang Zhu and Jing Zhao
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20537H, Edge Article

Supramolecular mechanics in a metal-organic framework
Joseph M. Ogborn, Ines E. Collings, Stephen A. Moggach, Amber L. Thompson and Andrew L. Goodwin
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20596C, Edge Article

Gold meets enamine catalysis in the enantioselective a-allylic alkylation of aldehydes with alcohols
Michel Chiarucci, Marzia di Lillo, Alessandro Romaniello, Pier Giorgio Cozzi, Gianpiero Cera and Marco Bandini
Chem. Sci., 2012,3, 2859-2863, DOI: 10.1039/C2SC20478A, Edge Article

Gram-scale synthesis and crystal structures of [8]- and [10]CPP, and the solid-state structure of C60@[10]CPP
Jianlong Xia, Jeffrey W. Bacon and Ramesh Jasti
Chem. Sci.,
2012, Advance Article, DOI: 10.1039/C2SC20719B, Edge Article

Catalytic enantioselective carbon-carbon bond formation using cycloisomerization reactions
Iain D. G. Watson and F. Dean Toste
Chem. Sci.,
2012, Advance Article, DOI: 10.1039/C2SC20542D, Minireview

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Chemical Science? Then why not submit to us today or alternatively contact us with your suggestions.

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A new silver-based route to metal insertion

US scientists have come up with a general synthetic method to prepare macrocyclic tetracarbenes with first, second and third row transition metals from both sides of the periodic table, using a dimeric silver transmetallating reagent.

The facile synthesis of bidentate and tridentate N-heterocyclic carbenes (NHCs) coupled with their resistance to oxidation has made these chelating ligands an attractive alternative to phosphines for many applications. Despite numerous uses for these strong sigma-donor ligands, one class of chelating NHCs that has not been as thoroughly investigated is tetradentate carbenes.

Link to journal article
Exploiting a Dimeric Silver Transmetallating Reagent to Synthesize Macrocyclic Tetracarbene Complexes
Z Lu, S A Cramer and D M Jenkins
Chem. Sci., 2012, DOI: 10.1039/c2sc20628e

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Green, highly reactive catalysts for bulk and fine chemicals

Highly active catalysts for manufacturing bulk and fine chemicals can be made by simply grinding metal acetate salts with pre-formed supports.

Heterogeneous catalysis is a key chemical manufacturing process and lies at the heart of green chemical processes. The use of catalysts can lead to greener reactions when compared to alternative routes. But many routes for making catalysts use halides as a starting point and the halides are difficult to remove from the final material.

UK scientists have prepared supported gold, palladium and gold-palladium catalysts by mixing the metal acetate precursors. The simple, reproducible and scalable preparation method ensures the catalysts prepared are halide free. They found that the removal of the halide from the preparation step and therefore from the final catalyst leads to a significant enhancement in performance compared to previously reported catalysts.

Link to journal article
Physical mixing of metal acetates: a simple, scalable method to produce active chloride-free bimetallic catalysts
S A Kondrat et al
Chem. Sci., 2012, DOI: 10.1039/c2sc20450a

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New supramolecular Alzheimer’s drugs

A cylindrical supramolecular complex (yellow) interacting with the central target region of the amyloid beta protein (green, white and red ribbon). Image credit: Xiaogang Qu

A cylindrical supramolecular complex (yellow) interacting with the central target region of the amyloid beta protein (green, white and red ribbon). Image credit: Xiaogang Qu

Supramolecular chemistry could provide a new avenue in the treatment of Alzheimer’s disease, say scientists in China. The group demonstrates for the first time that supramolecular complexes can inhibit the aggregation of a peptide thought to cause Alzheimer’s disease.

Alzheimer’s disease (AD) is the most common cause of dementia among the elderly and is estimated to affect over 35 million people worldwide, a figure which is expected to triple by 2050. One of the pathological hallmarks of the disease is the polymerisation of amyloid β-peptides (Aβ) into insoluble fibrous protein aggregates known as plaques. Scientists have been trying to develop inhibitors of Aβ aggregation as a therapeutic and preventive strategy for AD treatment. Most reported Aβ inhibitors are small organic molecules or peptides, many of which act non-specifically.

Read the full article in Chemistry World

Link to journal article
Metallosupramolecular Complex Targeting a/ß Discordant Stretch of Amyloid ß Peptide

H Yu et al
Chem. Sci., 2012, DOI: 10.1039/c2sc20372c

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MOF gate opens selective CO2 gas storage door

The MOF incorporating carboxyl and pyridyl groups within its cavity selectively adsorbs CO2 over ethyne. Image credit: Martin Schröder

The MOF incorporating carboxyl and pyridyl groups within its cavity selectively adsorbs CO2 over ethyne. Image credit: Martin Schröder

UK researchers have designed a metal–organic framework that, unusually, selectively adsorbs CO2 over ethyne by a dynamic gate-opening mechanism and has potential applications in fuel gas separation.

Metal–organic frameworks, or MOFs, comprise metal clusters or ions complexed to organic ligands, forming an extended crystalline, often porous, structure. The pore sizes can be tuned by careful design, and as such, they are widely investigated for gas storage and separation technologies. However, most MOFs are usually selective to ethyne adsorption over CO2, limiting their application, as the intermolecular interactions between ethyne and the MOF are stronger.

Now, Martin Schröder at the University of Nottingham, and colleagues, have synthesised a MOF that shows dynamic phase changing behaviour induced by CO2, inverting the usual selectivity to ethyne.

Read the full article in Chemistry World

Link to journal article
Selective CO2 uptake and inverse CO2/C2H2 selectivity in a dynamic bifunctional metal–organic framework
W Yang et al
Chem. Sci., 2012, DOI: 10.1039/c2sc20443f

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Top ten most accessed articles in June

This month sees the following articles in Chemical Science that are in the top ten most accessed:-

Enantioselective total synthesis of (+)-ibophyllidine via an asymmetric phosphine-catalyzed [3 + 2] annulation
Ian P. Andrews and Ohyun Kwon
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20468A, Edge Article

Rethinking the Term “Pi-Stacking”
Chelsea R. Martinez and Brent L. Iverson
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20045G

Towards “drug-like” indole-based transmembrane anion transporters
Stephen J. Moore, Marco Wenzel, Mark E. Light, Rebeka Morley, Samuel J. Bradberry, Patricia Gómez-Iglesias, Vanessa Soto-Cerrato, Ricardo Pérez-Tomás and Philip A. Gale
Chem. Sci., 2012,3, 2501-2509, DOI: 10.1039/C2SC20551C, Edge Article

Catalytic enantioselective carbon-carbon bond formation using cycloisomerization reactions
Iain D. G. Watson and F. Dean Toste
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20542D, Minireview

Crossed Intermolecular [2+2] Cycloaddition of Styrenes by Visible Light Photocatalysis
Michael A. Ischay, Michael S. Ament and Tehshik P. Yoon
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20658G, Edge Article

Copper-Catalyzed Decarboxylative Alkenylation of Sp3 C-H Bonds with Cinnamic Acids via A Radical Process
Zili Cui, Xiaojie Shang, Xiang-Feng Shao and Zhong-Quan Liu
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20712E, Edge Article

A highly selective ratiometric near-infrared fluorescent cyanine sensor for cysteine with remarkable shift and its application in bioimaging
Zhiqian Guo, SeongWon Nam, Sungsu Park and Juyoung Yoon
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20540H, Edge Article

Accelerated aging: a low energy, solvent-free alternative to solvothermal and mechanochemical synthesis of metal-organic materials
Matthew J. Cliffe, Cristina Mottillo, Robin S. Stein, Dejan-Krešimir Bučar and Tomislav Friščić
Chem. Sci., 2012,3, 2495-2500, DOI: 10.1039/C2SC20344H, Edge Article

Azulene-based conjugated polymers: unique seven-membered ring connectivity leading to stimuli-responsiveness
Masahito Murai, Elizabeth Amir, Roey J. Amir and Craig J. Hawker
Chem. Sci., 2012, Advance Article, DOI: 10.1039/C2SC20615C, Edge Article

Dialkylbiaryl phosphines in Pd-catalyzed amination: a user’s guide
David S. Surry and Stephen L. Buchwald
Chem. Sci., 2011,2, 27-50, DOI: 10.1039/C0SC00331J, Perspective

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Chemical Science? Then why not submit to us today or alternatively contact us with your suggestions.

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