February 2012 – Chemical Communications Blog

Archive for February, 2012

RSC Publishing poster prizes awarded at ISMSC

24 Feb 2012

Congratulations to the following students who were awarded ChemComm, Dalton Transactions and Organic & Biomolecular Chemistry poster prizes at the 2012 International Symposium on Macrocyclic and Supramolecular Chemistry (ISMSC) at the University of Otago in Dunedin, New Zealand:

Jean-Francois Ayme (Edinburgh) – “Pentameric Circular Helicates as a Scaffold for a Molecular Pentafoil Knot”
Jessica Holmes (Melbourne) – “Supramolecular Systems of Cyclotricatechylene”
David Hvasanov (UNSW) – “Photoinduced membrane proton-pumping via polymersomes as chloroplast mimics”

The poster prize winners with Professor Phil Gale from the ISMSC-2012 International Advisory Committee (photo courtesy of Scott Cameron from the Brooker group)

Nominations for the 2013 Cram Lehn Pedersen prize to be awarded at ISMSC-8 in Crystal City, Virginia, USA, will open later in the year. Stay tuned to the ChemComm blog for details.

Related news:
Cram Lehn Pedersen Prize awarded at ISMSC

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DNAzyme logic-controlled biofuel cell for self-powered biosensors

24 Feb 2012

US scientists have made the first DNAzyme-controlled biofuel cell, an important step on the road to self-powered medical diagnostics, they claim.

Biofuel cells (BFCs) use enzymes or microbes to oxidise fuels. Integrating them with logic-based biosensing systems provides a way to correlate the relationship between multiple target analytes in complex samples according to Boolean logic (which uses AND, OR and NOT operators) without the need for external power.

Joseph Wang and colleagues at the University of California, San Diego, used DNAzyme-based biochemical signals to control the power output of a BFC. DNAzymes are biocatalytic nucleic acids that are widely used for biosensing but have never before been used to control a BFC. Wang demonstrated that the biosensor can determine the presence of a specific target in the absence of another related target in a single test.

While this is a proof-of-concept study, Wang says that self-powered diagnostics may be realised if pathologically relevant targets were applied to the BFC.

Read Wang’s ChemComm communication, free for a limited period.

Also of interest:
DNAzymes for sensing, nanobiotechnology and logic gate applications

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Reminder: ChemComm–RSC Prizes & Awards Symposium in London

20 Feb 2012

Don’t miss out on the ChemComm–RSC Prizes & Awards Symposium in association with the RSC Analytical Division!

Date: Wednesday 22nd February 2012
Location: Imperial College London, UK
Time: 1300-1800

The purpose of this event is to bring together scientists in a stimulating and friendly environment to recognise the achievements of individuals in advancing the chemical sciences and also to foster collaborations. The symposium will appeal to academic and industrial scientists with an interest in analytical science, protein structure and interactions, and biosensors. Attendance at the symposium is FREE OF CHARGE and student participation is strongly encouraged.

The following distinguished scientists have agreed to speak:

Dr Perdita Barran, University of Edinburgh, UK (ChemComm sponsored speaker) – Resolving solution structures in the absence of solution
Professor Carol V Robinson, University of Oxford, UK (RSC Interdisciplinary Prize winner) – Membrane protein complexes at last
Professor G Marius Clore, NIDDK, National Institutes of Health, USA (RSC Centenary Prize winner) – Exploring sparsely-populated states of proteins and their complexes by paramagnetic and diamagnetic NMR
Professor Albert Heck, Utrecht University, the Netherlands (ChemComm sponsored speaker) – Modern biomolecular mass spectrometry and its role in studying virus structure, dynamics, and assembly
Professor R Graham Cooks, Purdue University, USA (RSC Centenary Prize winner) – Mass spectrometry simplified: ambient ionization and miniature mass spectrometers
Professor Anthony P F Turner, Linköpings University, Sweden (RSC Theophilus Redwood Award winner) – Biosensors: Sense and Sensibility

For further details and to register your interest, please contact Anne Horan.

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First total synthesis of mucosin

17 Feb 2012

Southampton chemists, lead by Richard Whitby, have completed the first total synthesis of the marine metabolite mucosin. As the synthesis is enantioselective (they made the (+) enantiomer), the team were able to determine the absolute stereochemistry of the natural compound (the (-) enantiomer), which was isolated from a sponge in the Mediterranean in 1997.

Of particular note in the synthesis is the use of a zirconium-induced co-cyclisation to install the stereochemistry of the four contiguous stereocentres around the unusual bicyclo(4.3.0)nonene core.

Read more about the work in their communication, which is free to download for a limited period.

If you’re interested in natural products, check out Natural Product Reports, which just published its regular and popular Marine Natural Products review article.

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Free analytical content in ChemComm

14 Feb 2012

The ChemComm–RSC Prizes & Awards Symposium takes place at Imperial College London on 22nd February 2012 with the theme of (bio)analytical science.

This is ChemComm‘s first UK-based symposium and to celebrate we’ve made some of our best analytical content free to access for a limited period.

We hope you enjoy these articles – but don’t delay! Free access only runs until 29th February.

Perspectives in imaging using mass spectrometry
Allison L. Dill, Livia S. Eberlin, Demian R. Ifa and R. Graham Cooks
Chem. Commun., 2011, 47, 2741-2746

Metal binding to a zinc-finger peptide: a comparison between solution and the gas phase
Yana Berezovskaya, Craig T. Armstrong, Aimee L. Boyle, Massimiliano Porrini, Derek N. Woolfson and Perdita E. Barran
Chem. Commun., 2011, 47, 412-414

Spectroscopic analysis of immobilised redox enzymes under direct electrochemical control
Philip A. Ash and Kylie A. Vincent
Chem. Commun., 2012, 48, 1400-1409

Fluorescent dye-doped silica nanoparticles: new tools for bioapplications
Se Won Bae, Weihong Tan and Jong-In Hong
Chem. Commun., 2012, 48, 2270-2282

Ultrasensitive fluorescence-based methods for nucleic acid detection: towards amplification-free genetic analysis
Rohan T. Ranasinghe and Tom Brown
Chem. Commun., 2011, 47, 3717-3735

An optimized isotopic labelling strategy of isoleucine-γ2 methyl groups for solution NMR studies of high molecular weight proteins
Isabel Ayala, Olivier Hamelin, Carlos Amero, Ombeline Pessey, Michael J. Plevin, Pierre Gans and Jérôme Boisbouvier
Chem. Commun., 2012, 48, 1434-1436

Nucleobase recognition at alkaline pH and apparent pKa of single DNA bases immobilised within a biological nanopore
Lorenzo Franceschini, Ellina Mikhailova, Hagan Bayley and Giovanni Maglia
Chem. Commun., 2012, 48, 1520-1522

FRET detection of amyloid β-peptide oligomerization using a fluorescent protein probe presenting a pseudo-amyloid structure
Tsuyoshi Takahashi and Hisakazu Mihara
Chem. Commun., 2012, 48, 1568-1570

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Building a nation of scientists

13 Feb 2012

Goverdhan Mehta talks to Sheena Elliott and Elinor Richards about the progress of science in India and the challenges scientists face

Goverdhan Mehta is a researcher, specialising in organic synthesis. He has helped to build institutions in India – the Indian Institute of Technology, Kanpur, the University of Hyderabad, and the Indian Institute of Science, Bangalore. He was director of the Indian Institute of Science (1998-2005) and vice chancellor of the University of Hyderabad (1994-1998).

Read the interview in Chemistry World

Link to Journal Article

Towards a temperature-guided molecular switch: an unusual reversible low-temperature polymorphic phase transition in a conformationally locked environment
Goverdhan Mehta and Saikat Sen
Chem. Commun., 2009, 5981-5983
DOI: 10.1039/B905651C

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Instant ecstasy detector

10 Feb 2012

An on the spot detector for ecstasy tablets has been made by scientists in Spain. The probe has been designed to detect the active ingredient in ecstasy – MDMA (3,4-methylenedioxymethamphetamine) – even when it is mixed with other common additives, which has been a challenge.

One way to detect ecstasy is a colorimetric test, but the test is not specific for MDMA and is unable to distinguish it from amphetamine and other common phenethylamines. Another method is chromatography, which can distinguish between these compounds but isn’t portable. Now, Tomás Torroba and his team from the University of Burgos have made a fluorimetric compound that can be used to identify MDMA. ‘The fluorogenic probe may be used as an in situ test for fast detection. It only needs a small sample and can be checked with a portable ultraviolet lamp,’ says Torroba.

The probe – a diaryl urea tagged with two fluorescent indicator units – is selective for primary and secondary amines, so it can only reveal that a primary or secondary amine is present. ‘It would be difficult to distinguish the difference between amphetamine or MDMA by the naked eye,’ says Torroba. ‘A mathematical trick is required.’

The fluorogenic probe (structure shown) was developed to detect MDMA from ecstasy tablets, even when it's mixed with other common additives such as sucrose, chalk and caffeine, showing a green fluorescent emission at 517nm

Read the full story in Chemistry World

Link to Journal Article
A turn-on fluorogenic probe for detection of MDMA from ecstasy tablets
Daniel Moreno , Borja Díaz de Greñu , Begoña García , Saturnino Ibeas and Tomás Torroba
Chem. Commun., 2012, Advance Article
DOI: 10.1039/C2CC17823K

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The first direct metalation of indazoles

10 Feb 2012

Paul Knochel from the Ludwig Maximilians University in Munich has developed a method to directly metalate and then functionalise N-protected indazoles.

Indazole heterocycles are important molecules in medicinal chemistry and methods to functionalise them are widely sought after. Direct metalation of indazoles at their 3 position is often problematic as this can quite easily lead to ring opening and formation of an aminonitrile product. Knochel overcame this problem by using a zinc reagent to form a bis-indazoylzinc compound.

The bis-indazoylzinc compound reacts with a wide range of electrophiles and can also undergo arylation in a Negishi cross-coupling reaction. In general, such reactions are not possible using normal metalation reagents. Future work will concentrate on the synthesis of biologically active molecules using this methodology.

If you want to find out more then download the ChemComm article, free for a limited period.

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Grinding gathers momentum for coordination polymers

03 Feb 2012

It is a fairly common assumption that the sample you are characterising is the same sample that you made at the lab bench. While it may indeed be the same sample, it may not be the same structure as Peter Stephens and Jagadese Vittal discovered.

By grinding coordination polymers with KBr (as is standard practise in solid state sample preparation for infrared characterisation), they generated coordination polymers with completely new structures – and as a result, completely different optical properties as well.

The team have attributed this to an exchange between the bridging ligands and the bromide ions from KBr. While this is an interesting avenue to explore for the preparation of new coordination polymers, Stephens and Vittal warn researchers working with such materials that observed changes in sample colour or texture during pre-characterisation preparation may not always be a physical phenomenon and to tread with caution…

Read the ChemComm article today.

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