ChemWeb Newsletter

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This week, The Alchemist finds out how to deodorize Godzilla and make multicomponent reactions with isonitriles more lab friendly, we also discover that novel cyclic peptides can stimulate nerve growth and could one day lead to a pharmaceutical solution to spinal cord injury. Also this week, mercury is rising over the US and non-crystalline solar panels could work even on duller days. Finally, testing olive oils for halogenated solvents is no longer a slippery issue.

Isonitriles have been described as the Godzilla of smells; they're that bad. This coupled with the fact that they require hazardous starting materials to make has kept them out of the synthetic laboratory. Now, Michael Pirrung and Subir Ghorai, of the University of California at Riverside have found a way to make a new class of these compounds that side-steps the starting material hazard and produces compounds that are more effective than the non-smelly counterparts of conventional isonitriles. More importantly, in one sense, the new reactants don't trigger a prehistoric reaction to their odor. Instead, they smell rather pleasantly, of soy, malt, natural rubber, mild cherry and even taffy, according to the Riverside team. The researchers carry out a metalation of the oxazoles to ring-open their ingredients and produce an isocyanoenolate that can be O-acylated to give an unsaturated isonitrile for conventional multicomponent reactions.

Researchers at the Universities of Bielefeld and Hamburg in Germany have found a group of cyclic peptides that imitate the HNK-1 carbohydrate from human natural killer cells. This carbohydrate is involved in many developmental biological processes of the nervous system, such as boosting motor neuron axon growth. It also promotes the growth of the fibers of muscle nerve cells. As such, medical scientists hope it will play a role in the repair of damaged peripheral nerves. Norbert Sewald (Bielefeld) and Melitta Schachner (Hamburg) scanned a linear peptide library HNK-1 antibody recognition. They then used the two most successful peptides as the prototypes for making a series of cyclic analogs. They tested the new compounds against motor neuron cell cultures and found that two of the cyclic peptides stimulated axon growth. In fact, these synthetic compounds were more effective than the natural substrate. The researchers suggest the further development of these compounds is a step towards a drug-based treatment for spinal injury.

A new report from the National Wildlife Federation (NWF) reveals that mercury pollution is making its way into almost all natural habitats across the US. The report claims this is exposing countless species of wildlife to potentially harmful levels of mercury. Report author Catherine Bowes compiled data from more than 65 published studies to find out how mercury levels have changed in a wide range of wildlife - fish, mammals, birds, reptiles and amphibians - living in freshwater, marine, and forest habitats. "Now that we have hard evidence that mercury is affecting more species than originally thought," says Bowes, "anything short of phasing out this toxic metal is inadequate."

Thin, flexible solar panels that are 40-50% more efficient could make solar energy a viable renewable energy source even in places that see less than their fair share of sunshine. According to Vikram Dalal of Iowa State University, hopes to use non-crystalline silicon - a more readily available and cheaper form of the element - in thin solar cells. Dalal is working with a thin film company PowerFilm to exploit discoveries in his lab that boost the photo efficiency of such materials and reduce the losses due to the panel being non-crystalline rather than composed of the inflexible crystalline semiconductor.

Spanish researchers have devised a new extraction and analytical procedure for detecting halogenated solvent residues in olive oil. Solvents such as bromoform are commonly used to extract olive from crude olive-pomace oils, but residues can be left behind. New regulations across the European Union strictly limit these residues and so quality control and regulators need detection technology that can cope with the limits. Jose Luis Gomez-Ariza of Huelva University explains that all these solvents are putative carcinogens so it is important that consumers are not exposed to higher than acceptable levels. Their method based on multiple headspace solid-phase microextraction (MHS-SPME) followed by the on-line coupling of gas chromatography with electron capture detection (GC-ECD) and with an ICP-MS for the determination of these residues means exhaustive extraction and works well within the EU limits.