ChemWeb Newsletter

Not a subscriber? Join now.August 5, 2004

contents
overview

The Alchemist Newsletter is back from a well deserved vacation and a move from London to Los Angeles. Now published by ChemIndustry, the newsletter and ChemWeb site will continue to be offered as a free services. We are working on some exciting new features for both the ChemIndustry and ChemWeb sites and will notify our users by email in the weeks to come. Contact us at Editor@ChemWeb.com with your comments and suggestions.




The origin of chiral asymmetry, or homochirality, in nature has been a long-standing puzzle in science. Why are almost all amino acids in nature left handed and almost all sugars right handed, for instance? Now, a team at Imperial College London have discovered that amino acids themselves may have been the amplifying molecules that tipped the balance in the early stages of life. Donna Blackmond and her colleagues measured the rates of reactions catalysed by the amino acid proline. Using sensitive calorimetry techniques they observed an enantiomeric excess even without any chiral bias in the reaction. The excess was only small but might have been enough in pre-biotic conditions to push nature one way and not the other.





A great deal more research into the so-called "green" solvents known as ionic liquids must be undertaken before companies like pharmaceutical giant GlaxoSmithkline would adopt them in preference to conventional volatile organic solvents. According to Alan Curzons of GSK's corporate environment, health and safety department speaking at the RSC's Ionic Liquids conference in London, more data is needed on the properties and benefits of using ionic liquid solvents over VOCs. He reckons progress in the field is too slow and that ionic liquids are unlikely to find a place in the industry within the next ten years at the present rate of research.





Ahmed Zewail and his colleagues at California Institute of Technology have developed a new ultrafast electron crystallography (UEC) technique for studying the surfaces of technologically important materials such as gallium arsenide. The crystallographic technique based on the diffraction of electrons rather than the more traditional X-ray, allows them to observe changes on a surface "frame-by-frame". UEC provides unprecedented atomic-scale resolution of surface dynamic. "We believe that UEC is now poised for many applications in the general area of surface science, nanometer-scale materials, and macromolecular structures," Zewail told X-factors webzine.





Seth Cohen of the University of California at San Francisco and his team have used a new type of computer model to design inhibitors for enzymes involved in diseases as diverse as cancer, arthritis, and heart disease. They say the new inhibitors should lack the problems that have plagued previous generations of inhibitors for these enzymes, such as toxicity, lack of oral availability, and rapid metabolism. Cohen's team tested eleven diverse compounds against a matrix metalloprotease enzyme and then used the results to fit the compounds to a new computer model of the enzyme's metal-containing active site. Cohen says the research is the first to use such an approach to modeling so aggressively and could lead to highly specific inhibitors for any one of the 26 MMP enzymes in the human body.





Forty-one steps and a yield of just 3.5% may not sound too impressive a total synthesis but it has taken chemists almost ten years to reconstruct the complex heptacyclic marine alkaloid, norzoanthamine, first extracted from the sea anemone <i>Zoanthus sp.</i> Masaaki Miyashita's team at Hokkaido University in Japan were first past the post in an international race to synthesise the molecule. The prize could be a new treatment for osteoporosis as norzoanthamine has promising biological activity against the bone-destroying disease in animal models.