ChemWeb Newsletter

Not a subscriber? Join now.September 6, 2005


The Alchemist this week reports on a timely text for the toxin responsible for botulism, a novel cancer inhibitor, the molecular models that mimic cell membrane channels, the effects of rising CO2 levels on tree growth or otherwise, and finally the serendipitous discovery of a new hydrogen storage material.

According to research using isotopically labeled carbon dioxide to study a mature forest outside the Swiss town of Basel, trees do not grow more in an atmosphere more rich in carbon dioxide, but simply "pump" through more CO2 than normal. Scientists at the Paul Scherrer Institute (PSI) and the University of Basel developed a new system to distribute CO2 to the treetops and found that contrary to general expectations there was no sustainable increase in biomass carbon. The question of whether or not rising atmospheric carbon dioxide levels would cause forests to grow more quickly and so store more carbon has vexed environmental scientists for years.

A rhenium-based catalyst can liberate hydrogen gas from organosilanes according to researchers at Purdue University. Mahdi Abu-Omar were looking for novel routes to the industrially important silanols when they spotted bubbles emerging from an experimental rhenium catalyst acting on an organosilane. They report details of their findings in the Journal of the American Chemical Society and suggest that the discovery could ultimately help speed the creation of viable hydrogen storage technology.

A system developed by researchers at the US Department of Energy's Pacific Northwest National Laboratory can detect the botulinin toxin in less than half an hour, a significant improvement on earlier tests. PNNL's Biodetection Enabling Analyte Delivery System, BEADS is used to isolate this most deadly of toxins from an environmental or other sample. Then, an antibody is used to purify and concentrate the pathogen or toxin to enable accurate and sensitive detection. A second, antibody a reporter antibody labelled with a fluorescent quantum dot binds to a different region on the toxin or pathogen and the subsequent fluorescence is used to quantify the concentration of the toxin. PNNL scientists say the system can be tailored to detect multiple pathogens or toxins, such as those from pathogenic bacteria Escherichia coli and Salmonella and ricin, simultaneously.

Researchers at the Children's National Medical Center in Washington, DC have discovered a compound that prevents cancer cells from producing a critical membrane component and so suppresses tumor growth. The compound OGT2378, a carbohydrate, inhibits the production of an enzyme that cancer cells need to make gangliosides, a compound involved in altering the cancer cell's surrounding environment and generating new blood vessels. "Cancer cells produce gangliosides at a much more rapid rate than normal cells," explains Stephan Ladisch, "By interfering with this process we can stop a tumor from growing in a rather dramatic fashion without damaging the normal tissue surrounding it."

German chemists have shown how porous molybdenum compounds can emulate the chemistry of cellular transport proteins. Achim Müller of Bielefeld University and colleagues have produced a series of channel-like structures using their well known talent for making giant molybdenum compounds. They found that the unique porous nanocapsule {{(MoVI)MoVI5O21 (H2O) 6}12 {MoV2O4- (SO4)} 30}722 behaves like a semi-permeable inorganic membrane that is open to the passage of water molecules and small cations, such as Li+, and as such can channel traffic in a similar manner to certain membrane channels.