Renewable Fuels

research highlights

nucleobase and the phosphate linker — to have proposed a chemical method that produce nucleic acid analogues with very could be used to upgrade more common and different properties. Metal-containing higher-yielding fermentation products into a variants have also been made, in which the mixture containing the desired hydrocarbons. two strands of the double helix are held together by metal–ligand coordination rather O O than hydrogen bonding. Now, James Tucker and co-workers 1.7 % 49.8 % at the University of Birmingham, UK, Eye of the beholder have taken the first steps towards making O O From pesky biochemists winning the a DNA mimic in which metals form an Nobel Prize in Chemistry, to the social integral part of the polymer backbone. < 0.5 %8.3 % construction of scientific ideas. Is it all On recognizing that the distance between just a matter of perspective? the two cyclopentadienyl (Cp) rings in O O ferrocene is very similar to the distance Considering the time of year, it would between adjacent sets of stacked base pairs be rude not to mention this year’s Nobel in B-DNA, the team set about designing and 4.2 % 2.8 % Laureates in Chemistry, Robert J. Lefkowitz making a nucleic acid analogue based on and Brian K. Kobilka. Being awarded the this well-known organometallic compound. Clostridium acetobutylicum is a bacterium prize “for studies of G-protein-coupled The resulting ferrocene nucleic acid that has been known for almost 100 years, receptors” resulted in a tedious furore (FcNA) structure is made up of a repeating and it produces, by fermentation, a mixture of owing to the awarding of the prize to

C3-linker–ferrocene–C3-linker–phosphate acetone, butanol and ethanol (widely known biochemists. The usual heavyweights unit, with one nucleobase connected to each as ABE). Toste and co-workers recognized of the blogosphere have done their of the Cp rings. Starting from a ferrocene that this classic mixture of two-, three- part deriding these banalities, though I monomer functionalized with coupling and four-carbon products harbour both particularly enjoyed John’s article at ‘It’s groups that are compatible with solid-phase electrophilic and nucleophilic carbon atoms The Rheo Thing’, highlighting the ‘impurity’ synthesis methods, an oligomer comprising such that a suitable chemical process might of two of the world’s leading ‘chemistry’ 8 ferrocene groups — and hence 16 thymine enable conversion to higher hydrocarbons. journals (http://go.nature.com/qqHOd4). nucleobases — was made using an automated The reactions involved are relatively simple The role of society in science, although nucleic acid synthesizer. — a combination of transition-metal- not a new concept (I would say one as old Following purification by reversed-phase catalysed dehydrogenation of the alcohols, as science itself), is one that is increasingly HPLC, the FcNA oligomer was characterized base-catalysed aldol reactions, dehydration developing in importance. For example, using a range of techniques including mass and a final reduction result in a formal society’s perception of genetically modified spectrometry and cyclic voltammetry. Future alkylation of the acetone. The key, however, is food has had widespread consequences for work will undoubtedly look at the binding to optimize the process to avoid the multitude its development, production and distribution properties of FcNA oligomers to determine of possible side reactions and obtain — worldwide. Two pieces relating to this boiling whether they can form duplexes (or depending on the reaction conditions — pot of anguish have recently caught my complexes of some sort) with other nucleic linear ketones with between five and eleven attention, one by science-policy academic acids. Moreover, the well-characterized carbon atoms (pictured). Jack Stilgoe of Responsible Innovation electrochemical behaviour exhibited by Development of these reaction who in response to an article on the ferrocene may prove to be a useful addition conditions into a process to produce various Rothamsted protests highlights the dangers to the properties usually associated with hydrocarbon fuels also requires integration of unstructured and polarized debate on nucleic acid structures. SC with the fermentation system. Here, Toste such ethical dynamite (http://go.nature. and co-workers have designed a two-phase com/pPcOmP); and a second by Michael RENEWABLE FUELS liquid-extraction system that allows the ABE Eisen of ‘it is NOT junk’ challenging the basis Catalytic upgrade products to be easily separated from the of “Proposition 37, which would require the Nature 491, 235–239 (2012). fermentation broth for direct input into the labeling of genetically modified foods” in the catalytic upgrade system. The overall process USA (http://go.nature.com/Y7qWst). Dwindling resources of crude oil and its converts up to 58% of the carbon in glucose Finally, academic Alice Bell, of ‘through increasing price, in addition to the threat of into ketones. A final step in the process will be the looking glass’, writes an intriguing piece climate change, have all resulted in a greater the integration with established procedures on the social construction of science (http:// focus on renewable fuels — particularly for the deoxygenation of the ketones. SD go.nature.com/AzaEby), challenging the biofuels, which are the result of biological perception (presumably of ‘scientists’) that carbon fixation. The most common biofuels Written by Stuart Cantrill, Stephen Davey and describing science as a social construct produced are ethanol and butanol, but these Russell Johnson. is negative. Bell writes “Saying science is can be difficult to integrate into the existing a social construction does not amount fuel-use infrastructure. Also, although to saying science is make believe” and biological production of higher hydrocarbons Correction continues to discuss the ‘social construction’ has been demonstrated, these routes tend to In the version of the Research Highlight of St Paul’s, CERN and scientific ideas. suffer from poor yields and titres (the amount ‘Materials chemistry: Compliant crystals’ of fuel produced per volume of fermentation originally published (Nature Chem. 4, 866; Written by Karl D. Collins who blogs at 2012), the wrong affiliation was given. http://karldcollins.wordpress.com broth). Now, Dean Toste and co-workers Corrected after print 23 October 2012. from the University of California, Berkeley,

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