Apr 17 2010
A novel nano-scale scientific tool in the form of a molecular switch was synthesized by two chemists from The Scripps Research Institute. This switch turns on or off depending on the presence of metal ions in the vicinity. The Skaggs Institute for Chemical Biology and the National Institutes of Health funded this work, with a fellowship support through the French Ministry of Foreign Affairs.
Termed as the ‘ouroborand,’ this molecule was named after a lizard type of animal that swallows its own body right from the head to the tail. It was named after the Greek mythical Ouroborus (tail-eater) that is shown always having its tail in the mouth and is considered as an eternity symbol usually. While sensing metals this molecular switch swallows or coughs out its own tail alternatively in the Scripps Research laboratory. The molecule, with one end having a tail and the other end a cup-shaped head, makes this switching possible. This symbol is almost similar to the structure of benzene in modern chemistry. August Kekule, a famous German chemist, dreamt about a serpent having its own tail in the mouth, more than a century back. He was motivated by this dream to suggest the benzene circular structure. Benzene is used commonly as an industrial solvent.
Skaggs Institute for Chemical Biology at Scripps Research’s director Julius Rebek informed that the tail of the molecule is positioned in its cavity when metals are absent in the surroundings. The molecule’s part that connects the tail with the head is able to curl around the metallic ions, pulling apart the head and the tail, springing open the molecule whenever zinc or other metallic ions are present, according to Rebek. When this metallic ion is removed, the tail makes a movement again and plug the molecule’s other end.
This molecular switch can have applications in labs as a useful tool for performing small controlled reactions inside a test tube, and it can come up as a novel technology that can be sensitive towards toxins, metals, and pollutants in the soil, air or water.
The Ouroborand molecule will be presented by Rebek at the Germany-based Kekule Institute at the University of Bonn. Fabien Durola, a post-doctorate fellow of Rebek and Rebek had jointly authored the Angewandte Chemie article that is titled ‘The Ouroborand: A Cavitand with a Coordination-Driven Switching Device.’ This title is available in online form.
Source: http://www.scripps.edu