Pioneering techniques for producing precisely the correct forms of chemical compounds have earned the 2001 Nobel prize in Chemistry.
Making the correct form of a drug can mean the difference between life and death. It was the incorrect form of the drug thalidomide, for example, which caused such distressing birth defects in the 1960s.
The 2001 winners 鈥� two from the US and one from Japan 鈥� devised catalysts to ensure that only the correct form is made, a process called asymmetric synthesis.
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The subtle differences arise because many chemical substances can exist as 鈥渃hiral pairs鈥�. Each twin is a mirror image of the other, one being 鈥渞ight-handed鈥� and the other 鈥渓eft-handed鈥�. This means that although they share the same chemical formula, they have different shapes.
There are many examples in nature and in the pharmaceutical and food industry of substances which are only active in one form. Asparagine, the sweetener, is an example.
Catalytic converter
Half the prize money of 拢690,000 goes to Barry Sharpless, at the Scripps Research Institute in La Jolla, California. He developed catalysts which orchestrate oxidation, one of the most fundamental chemical reactions. His catalysts ensure that only one chiral form of a molecule is manufactured.
The other half is shared between Ryoji Noyori of Nagoya University in Chikusa, Nagoya, and William Knowles, a retired chemist now living in St Louis, Missouri.
They received their award for developing catalysts which add hydrogen asymmetrically. Knowles used transition metals to make the correct hydrogenated mirror image. His triumphs included a process for producing L-Dopa, a drug for treating Parkinson鈥檚 disease.
Noyori has developed many general chiral catalysts, routinely used in chemistry labs the world over.
鈥淚鈥檓 absolutely and utterly delighted for them,鈥� says Steve Ley, president of the UK鈥檚 Royal Society of Chemistry. 鈥淭heir impact on the pharmaceutical industry has been truly enormous 鈥� it鈥檚 a fundamentally important concept.鈥�
