ChemWeb Newsletter

Not a subscriber? Join now.January 9, 2007

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overview

The first Alchemical overview of the year brings news of record-breaking conjugated molecules that could lead to new forms of optical data processing, a warning over the use of antiviral drugs in the event of a flu pandemic, and while a rolling stone may gather no moss a small peat tussock could overturn the climatic cart. Also in this issue, US chemists have finally synthesized thin films of once impossible polymers from 1,2-disubstituted ethylenes and a sweet and fat solution to cancer therapy may soon be on the cards.




Conjugated organic molecules with electronic "speed-bumps" can interact with light more strongly than any previous materials, according to an international research team. Researchers from Washington State University, the University of Leuven in Belgium and the Chinese Academy of Sciences have developed and tested an entirely new class of chromophores. The chemists in China synthesized the compounds, which were then evaluated using theoretical calculations by scientists at WSU and then tested the optical properties were tested by a team of chemists in Belgium. "To our great excitement, the molecules performed better than any other molecules ever measured," says WSU physicist Mark Kuzyk. The new materials could become a template for novel chromophores for high-speed optical switches.





British scientists have found that the widespread use of the antiviral drug Tamiflu in the event of an avian influenza pandemic in humans could lead to the emergence of drug-resistant strains of the virus in wild birds. A team at the Centre for Ecology and Hydrology in Oxford publish findings in the January issue of Environmental Health Perspectives (EHP) that suggest that Tamiflu can persist in rivers and waste water, and could enter wildfowl populations through this route. Nations worldwide have stockpiled Tamiflu for the treatment influenza but the active ingredient of the drug would be excreted into sewers for several weeks during a pandemic and its stability means it would withstand biodegradation long enough for any infected birds to drink the contaminated water and pass emergent strains of resistant virus on to other birds.





Peat moss contains approximately one third of global carbon reserves, according to researchers at the Norwegian University of Science and Technology (NTNU) particularly in the form of enormous amounts of the greenhouse gas methane. NTNU's Hans Stenøien suggests that when the global average temperature rises by one degree Celsius large amounts of these carbon reserves could be released into the atmosphere. At that point, he suggests, that climate change will be entirely beyond any control we may have had. The Norwegian proverb "small tussocks overturn great loads" is rarely more fitting, because now it turns out that marshes and mosses are very important for the global climate.





A new class thin film polymers previously thought inaccessible to organic chemists has been produced by US researchers. Chris Snively and Jochen Lauterbach of the University of Delaware knew that the textbooks precluded the possibility of synsthesizing polymers from 1,2-disubstituted ethylenes. However, they did not let such received wisdom deter them in their efforts and finally their efforts paid off with the formation of a new type of ultra-thin polymer film. "There's been a rule that these molecules wouldn't polymerize," Snively says, "When I first saw that in a textbook when I was in graduate school, I said to myself, 'Don't tell me I can't do this.'" They mapped out the original synthesis some time ago, but have now used a vapor deposition technique to produce nano-thin films of these materials and are currently investigating their properties. Until the current polymer textbooks are revised, the researchers will continue to relish advising their students to make a marginal correction to their notes.





Gopalan Sampathkumar and colleagues at Johns Hopkins University have patented a new combination of a sugar molecule and a short-chain fatty acid, butyrate, which they claim offers an entirely new approach to cancer therapy that side-steps radiation and cytotoxic drugs. The team has built on twenty-year-old findings that butyrate itself can slow the spread of cancer cells. Butyrate forms naturally at high levels in the digestive tract when symbiotic bacteria feed on dietary fiber. Efforts to use standalone butyrate as an anticancer drug have failed because of the high doses needed. Other researchers have added sugars to butyrate to mask its toxicity at these doses. However, the JHU team selected their sugar, N-acetyl-D-mannosamine, or ManNAc, with the aim of creating a new synergistic compound that would serve a double blow to cancer cells. Although the study of the exact molecular mechanism is in its early stages, the researchers believe the separate chemical components work together to bolster the cancer-fighting power of butyrate. The double attack triggers cellular suicide, also called apoptosis, in the cancer cells.