ChemWeb Newsletter

Not a subscriber? Join now.March 28, 2006


In The Alchemist this week, a glowing reporter spots biological zinc, a new class of enzyme inhibitor that starves the malaria parasite of its human blood supply, and how to convert slimy waste oil into compost. The Alchemist, also discovers how Europeans are addressing concerns over chemical unknowns. Finally, we learn that this week's ACS meeting is truly all sweetness and light.

A biosensor that can detect the minute quantities of zinc in our bodies could settle the debate once and for all as to whether zinc dietary supplements are good or bad. Millions of people take zinc supplements in the belief that they may have a deficiency of this essential trace element, especially when they are suffering from the common cold. However, there is scant evidence of what zinc levels in our bodies should be. Now, Rebecca of the University of Maryland and colleagues there and at the University of Michigan have developed an engineered fluorescent protein whose glow in the presence of zinc can be seen under the microscope. The team suggests that the new technique will help improve our understanding of the biological role of zinc as well as expose details of its involvement in plaque formation in Alzheimer's disease, how prolonged seizures or stroke kill brain cells, and how the cell normally allocates zinc to different proteins.

Malaria has killed more people throughout our history than any other cause, yet finding a way to defeat this parasitic infection remains a serious problem. Now, François Diederich of the Swiss Federal Institute of Technology in Zurich and colleagues at the University of Victoria, Canada, Washington University, St. Louis, USA, and Actelion Pharmaceuticals in Switzerland are focusing their attention on a new pharmaceutical target through which to attack the malaria parasite Plasmodium falciparum. The target is a group of enzymes known as plasmepsins, which belong to the family of aspartic protease enzymes. These enzymes dismantle human hemoglobin to release the amino acids plasmodia need to grow. Computer modeling of the plasmepsin II active site has led to a new group of enzyme inhibitors, which the team is currently optimizing for efficacy. Human proteases are fortunately unaffected, which bodes well for avoiding side-effects.

The waste products of the petroleum industry are among the most environmentally noxious materials to manage and are very difficult to treat. Now, Russian scientists at the Kazan State University and the Open Joint-Stock Company Nizhnekamskneft have suggested that simple composting could be the answer. They have demonstrated how toxic oil-slimes can be made readily biodegradable and so self-composting. Oil-slimes consist of oil carbohydrates and the by-products of processing, including asphaltic-resinous substances, phenols, xylols, styrenes and numerous other toxic and carcinogenic substances. The scientists have carried out field trials on oil-slimes from Nizhnekamskneft's slime accumulators and found that compost beds containing the upper, dried fraction from the accumulators could be reduced by 85% oil content within 18 months. The compost is benign enough to promote the growth of radishes.

Scientists at the Annual Meeting of the EU supported research Network CASCADE, March 28-31, in St Malo France will call for joint discussions with consumers and industry to focus on EU chemicals legislation. More than 100,000 chemicals are present in the environment, but the EU believes information regarding their health effects is inadequate for at least 80,000 of these. EU proposed REACH legislation suggests that all chemicals used in industry must be registered, evaluated and approved and that the spread of potentially harmful chemicals be limited. However, the legislation must be based on scientific data and decisions made accordingly. "We believe that the EU Parliament must consider long-term effects of exposure to chemicals and protect the European population from involuntary exposure to potentially toxic chemicals", says Professor Jan-Åke Gustafsson, Sweden's Karolinska Institute, coordinator of CASCADE.

Chemists at this week's ACS meeting are to hear how their colleagues are exploring a variety of sugar alternatives, including new artificial sweeteners and non-calorie sweetness enhancers. Researchers at Senomyx, Inc. in La Jolla, California, for instance, are developing compounds that can enhance sweetness or saltiness by activating or blocking certain taste receptors. An aspartame derivative called Neotame could also help reduce calorie counts for beverages by enhancing sweetness more effectively without the need to use high-fructose corn syrup. Additionally, Belgian researchers discuss Stevioside, a non-caloric sweetener derived from the South American shrub Stevia rebaudiana. They have demonstrated efficacy and safety in this compounds and suggest it could be a potent weapon in the battle against obesity and type II diabetes.