Chemical Communications Blog

Film to aid drug metabolism study

05 Jul 2012

A way to study drug metabolism using cytochrome P450 enzymes (which are involved in the metabolism of over 60% of clinically used drugs) has been developed by scientists in China.

The team made a film of indium tin oxide nanoparticles (they have good conductivity) and cytochrome P450s encapsulated by chitosan (which are biocompatible) on a carbon electrode. They were able to bioelectronically initiate cytochrome P450 catalysis by replacing electron donation from expensive nicotinamide adenine dinucleotide phosphate with electrodes.

The system has potential for applications in drug discovery and development by monitoring substrate metabolism and enzyme inhibition. Other applications include biosensors for toxicity analysis and bioreactors for chemical synthesis.

Link to journal article
Electrochemically Driven Drug Metabolism via Cytochrome P450 2C9 Isozyme Microsomes with Cytochrome P450 Reductase and Indium Tin Oxide Nanoparticle Composites
X Xu et al
Chem. Commun., 2012, DOI: 10.1039/c2cc33575a

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Macrocycle insulation for molecular wires

05 Jul 2012

By Cally Haynes.

Researchers in Texas are using rotaxane formation to sterically protect or “insulate” molecular wires.

Molecular wires, in which an unsaturated linker separates two or more redox active metal sites, are of great research interest. These structures allow phenomena such as electron delocalisation or transport between the two redox sites. John Gladysz’s group at Texas A&M University have an ongoing interest in dimetallic polyynediyl complexes, in which two metal centres are linked by conjugated polyynediyl linkers that they now hope to “insulate” to reduce interactions between wires and the external environment. A previous approach used long alkyl bis-phosphine, which wrapped around the wire in a double helix to complex both metal centres. However, this gave two enantiomers, which interconverted rapidly in solution via uncoiling of the protective ligands.

The Gladysz group are now reporting a straightforward solution to this problem. They found that by synthesising their bis-platinum wire in the presence of a 33-membered macrocycle, they could incorporate the wire as the thread of a rotaxane complex. This provides a more robust protection for the wire which is unaffected by dynamic processes.

space filling representation of the rotaxane

This work shows a fantastic application of rotaxane chemistry for protection of a molecular wire. What’s more, the synthesis of this rotaxane is adaptable, and the Gladysz group are working on exciting new and improved systems including longer polyynediyl linkers and redox inactive macrocycles to improve the properties of the insulated wires.

The full communication can be downloaded here.

Cally Haynes

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Why some metal hip replacements fail

04 Jul 2012

By Rachel Blakeburn.

Hundreds of thousands of patients have been fitted with metal-on-metal hip joints

An investigation into why metal-on-metal hip joints fail long before other types of joints, such as metal-on-polyethylene and ceramic-on-ceramic, has revealed how the metal particles shed by the joints grinding against each other damage surrounding cells. The work, carried out by scientists in the UK, Canada, the Netherlands and the US, could lead to ways to predict which patients will have problems with these joints.

One theory why metal-on-metal hip implants fail points to the debris that is generated as the joints wear. It is thought that the debris is not compatible with human tissue, which causes the metal hip joints to fail, but it’s not known why.

Read the full article in Chemistry World

Link to journal article
Chemical Speciation of Nanoparticles Surrounding Metal-on-Metal Hips
A E Goode et al
Chem. Commun., 2012, DOI: 10.1039/c2cc33016d

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Kitchen nanodot chemistry

02 Jul 2012

By Rachel Blakeburn.

For carbon nanodots, simply heat soy milk for three hours. The milk undergoes carbonisation, surface functionalisation and doping

Water-soluble, nitrogen-doped fluorescent carbon nanodots (FCNs) have been made by simply heating soy milk. This cheap and green approach produces a carbon nanomaterial suitable for bioimaging applications, and has already shown promise as an electrocatalyst, say scientists in China.

There have already been several successful demonstrations using natural biomass as a precursor for producing nanomaterials. Inspired by these endeavours, Shaojun Dong and colleagues at the Chinese Academy of Sciences have developed a simpler, time-saving method for preparing bifunctional nanomaterials, in just three hours, using soy beans.

Read the full article in Chemistry World

Link to journal article
Bifunctional fluorescent carbon nanodots: green synthesis via soy milk and as metal-free electrocatalysts for oxygen reduction
C Zhu, J Zhai and S Dong
Chem. Commun., 2012, DOI: 10.1039/c2cc33844k

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Deadline Approaching – ICPOC 21 poster abstracts

29 Jun 2012

By Rachel Blakeburn.

There is still just time to submit your poster abstract to the 21st IUPAC International Conference on Physical Organic Chemistry (ICPOC 21) but don’t delay.

The deadline date of 13 July is for both poster abstracts and early bird registrations.

Why join ICPOC21?

Professor Hiromitsu Maeda, Ritsumeikan University, Japan has won the 2012 ChemComm Emerging Investigator Lectureship and will delivering his lecture at ICPOC 21.

This annual award recognises an emerging scientist in the early stages of their independent academic career. Professor Maeda’s has been particularly commended for his contributions to the fields of organic chemistry, supramolecular chemistry and materials science.

In addition to the outstanding plenary sessions, there will be three parallel sessions over the five days comprising invited lectures and contributed talks, as well as poster sessions.

A broad range of scientists from across the whole community who share a quantitative perspective on chemistry will be there, providing an opportunity to discuss and celebrate the current status, development, and the future of physical organic chemistry.

Make sure you are one of them! Don’t miss the poster abstract submission and early bird registration deadline – 13 July.

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ChemComm’s Impact Factor climbs up once more – 6.169!

28 Jun 2012

By Ross McLaren, Development Editor.

Another Impact Factor announcement and another increase for ChemComm

Thomson Reuters has just released the 2011 Journal Citation Reports ^® and it’s great news for ChemComm.

Our Impact Factor* (IF) has grown once again and now stands at 6.169.

The journal’s success would not be possible without the loyalty of our authors and the commitment of our referees – thank you to all of you who have helped contribute to this impressive figure. And, of course, we sincerely thank our Editorial and Advisory Boards for their continued dedication and commitment.

With an average time of just 55 days from receipt to publication, ChemComm has the fastest average publication times of any chemical journal and with our latest IF as well, it’s clear why ChemComm is the home of urgent, high impact communications from across the chemical sciences.

Join your colleagues today and submit your next high impact communication to ChemComm.

Find out how other RSC journals are ranked in the latest Impact Factor release >

*The IF provides an indication of the average number of citations per paper. Produced annually, IFs are calculated by dividing the number of citations in a year, by the number of citeable articles published in the preceding two years.

2011 Journal Citation Reports ^®, (Thomson Reuters, 2012).

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For clean water, just add sunlight

27 Jun 2012

By Rachel Blakeburn.

Capillaries coated on the inside with photocatalytic materials induced a photocatalytic reaction by pulling up a solution under the action of capillary forces

Researchers from Japan have developed a photocatalytic reactor for a water purifier that does not require batteries. Rather than using an external power source to pump water through the reactor, the system uses diffusion and capillary action to achieve an entirely non-electric reactor.

In addition to water purification itself, it is also important to ensure a constant and efficient transfer of contaminated water into the reactor and clean water out. This is normally achieved by an electric or fuel pump, but in areas where the power supply is often disrupted or is scarce, another approach is needed.

Read the full article in Chemistry World

Link to journal article
Novel Photocatalytic Microreactor Bundle that does not Require an Electric Power Source
K Katayama, Y Takeda and S Kuwahara
Chem. Commun., 2012, DOI: 10.1039/c2cc33525e

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A new catalyst for asymmetric aziridination

26 Jun 2012

By Alice E. Williamson.

Aziridines are used extensively as intermediates for organic synthesis. The strained three-membered heterocycles reveal amino groups on ring-opening and therefore provide access to a variety of useful products. Enantioselective methods for forming aziridine rings are highly desirable because enantiopure amino-compounds represent important targets for both natural product synthesis and in the discovery of novel therapeutics.

Researchers from Kyushu University in Japan have reported a newly designed Ru(CO)salen complex (4), which acts as an efficient catalyst for asymmetric aziridination of alkenes.

Reaction of olefinic substrates (1) with 2-(trimethylsilyl)ethanesulfonyl (SES) protected azide (2) in the presence of the Ru(CO)salen complex 4 afforded enantioenriched aziridine products. 4 efficiently decomposes azides under ambient conditions and also catalyses asymmetric aziridination.

Judicious selection of an appropriate azide protecting-group also influenced the design of the catalyst. The researchers chose to include an appropriately located C–F bond within the ligand in order to improve tolerance of 4 to reacting electrophiles.

Low catalyst loadings enabled the highly enantioselective azirdination of a variety of substrates possessing conjugated or non-conjugated terminal or cyclic olefins.

Find out more – download the communication for free for a limited period.

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Additional benefit of cancer drug

21 Jun 2012

By Rachel Blakeburn.

A new clinically used cancer drug thought to work by inhibiting kinase enzymes also strongly inhibits carbonic anhydrase (CA) enzymes, reveal scientists in Italy.

Scientists did not evaluate the CA inhibition activity of pazopanib before its approval for the treatment of a variety of different cancers, including lung, breast and ovarian cancers. But Claudiu Supuran and colleagues recognised part of the drug’s structure – a primary sulfonamide moiety – is often found in drugs that can inhibit CAs. So they tested pazopanib along with some other related structures and found that the drug did indeed inhibit CAs. They estimate that a significant proportion of the drug’s therapeutic effect on hypoxic tumors is due to its strong CA inhibitory properties.

Link to journal article
Polypharmacology of sulfonamides: Pazopanib, a multitargeted receptor tyrosine kinase inhibitor in clinical use, potently inhibits several mammalian carbonic anhydrases
J-Y Winum et al
Chem. Commun., 2012, DOI: 10.1039/c2cc33415a

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Chemical Communications Blog

Film to aid drug metabolism study

Macrocycle insulation for molecular wires

Why some metal hip replacements fail

Kitchen nanodot chemistry

Deadline Approaching – ICPOC 21 poster abstracts

ChemComm’s Impact Factor climbs up once more – 6.169!

For clean water, just add sunlight

A new catalyst for asymmetric aziridination

Additional benefit of cancer drug

Top ten most accessed articles in May

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