ChemWeb Newsletter

Not a subscriber? Join now.May 23, 2012

contents
publishers' select

A HIGH-INTEREST CHEMWEB MEMBER BENEFIT

Free Selected Full Text Articles

ChemWeb members now have access to selected full text articles from Chemistry publishers such as Wiley, Elsevier and Springer. Members can download a selection of articles covering a broad range of topics direct from the pages of some of the most respected journals in chemistry. Explore some of the latest research or highly cited articles. Not yet a ChemWeb member? Membership is free and registration takes just a minute.

arrowView free select full text articles



overview

This week's Alchemist gets a push from a peristaltic chemical reaction, learns about the offspring of frustrated radicals, hears how trace amounts of water can speed up some reactions and is confused by cholesterol, orphans find new homes in pharma news and finally an award for branched polymers.




175,000 patients from 27 separate trials suggests that even healthy people could lower their risk of heart disease by taking regular statin drugs to lower the levels of "bad" LDL (low-density lipoprotein) cholesterol. The second paper reveals that raising levels of "good" HDL (high-density lipoprotein) cholesterol does not necessarily reduce the risk of heart disease. This latter finding runs counter to the pharmaceutical industry's motivation for find drugs to raise HDL cholesterol.





Researchers at the Fred Hutchinson Cancer Research Center in Seattle and their colleagues have demonstrated that an inexpensive "orphan drug" previously tested for treating sleep disorders is also a potent inhibitor of cancer cell growth. The study involved high-throughput robotic screening that focused on a specific gene associated with cancer to identify compounds in a database that can inhibit the protein expressed by the gene. The compound targets the products of the "Myc" gene which is over-active in brain, breast, lung, ovary and liver cancers. The same approach opens up a new route to finding drugs to fight cancer with the added advantage of identifying orphan drugs that have already gone through initial safety testing.





The 2012 Centenary Prize from the Royal Society of Chemistry has been awarded to Craig Hawker, Director of the Materials Research Laboratory at the University of California Santa Barbara. Hawker is renowned for his pioneering work in the synthesis of novel polymers, such as starburst dendrimers, and his inspirational efforts that have influenced a generation of chemists. "I am thrilled with this honor, which is really a reflection of the wonderful students and researchers that work with me, coupled with the tremendous environment for multidisciplinary research that has been created at UCSB," Hawker says. "Having world-class colleagues and collaborators makes the hard work fun."





Chemists in Japan have demonstrated that the oscillating Belousov-Zhabotinsky reaction can be exploited to push a cargo along a length of smart polymer tubing in a process not unlike the peristaltic contractions of the intestine. Yusuke Shiraki and Ryo Yoshida of the University of Tokyo incorporated the ruthenium catalyst of the B-Z reaction into an N-isopropylacrylamide polymer gel to mimic peristalsis. The oscillating reaction starts up when this material is added to a solution of malonic acid, sodium bromate and nitric acid. The team has been developing smart gels since the 1990s, but the directional pumping of this chemical system might now have potential in "powering" microelectromechanical systems (MEMS) or driving reagents and analytes around a lab-on-a-chip.





Persistent nitroxide radicals can be generated by exploiting the ability of a frustrated Lewis pair (FLP) to capture nitric oxide through the synergistic action of the acid-base species. FLPs have both an acid and a base component but their bulky substituents preclude them from getting close enough to neutralize one another, hence their frustration. This frustration is equivalent to pent up reactivity, of course. Now, researchers in Germany and the US have shown that FLPs comprising dimesitylphosphanes and bis(pentafluorophenyl)borane can trap nitric oxide to form novel radicals. These materials can in turn abstract hydrogen from cyclohexadiene and toluene, leading to O-substituted alkoxyamine derivatives, a potentially useful step for organic synthesis.





Forget a spoonful of sugar, a drop or two of water is what makes the reaction go down. For reactions in which hydrogen is one of the reactants such as a hydrogenation or a hydrogenolysis the addition of a trace quantities of water can accelerate the process, according to international researchers. Writing in the journal Science, teams led by Manos Mavrikakis of the University of Wisconsin-Madison and Flemming Besenbacher at the University of Aarhus, Denmark, explain for the first time how water can speed up such reactions without requiring the heat to be turned up, even if it is added at the parts per million level. The team investigated experimentally and theoretically the effects of water on metal oxide catalysts and demonstrated tiny numbers of water molecules can increase the diffusion of hydrogen atoms by 16 orders of magnitude by acting as a medium for proton hopping.