Helical springs as a color indicator for determining chirality and enantiomeric excess
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A colour-changing compound that can precisely indicate the ‘enantiomeric excess’ (ee) of chiral molecules could provide a convenient method to measure pharmaceutical purity.
Many molecular systems in nature are chiral, existing in only one of two mirror-image forms. For pharmaceuticals to interact with the body as intended, they must have the correct chirality — a mismatch would be like trying to slide a right hand into a left glove. Drug makers measure the ee of their products to confirm they have produced a molecule of the correct chirality.
Now, researchers at Kanazawa University in Japan have helped to develop a novel colour-changing ee indicator.
The team developed a polymer shaped like a helical spring, which changes shape — and colour — when it interacts with chiral amine drugs. Differences of less than 2% ee between samples produced colour changes discernible to the naked eye. When the colour change was analysed by digital imaging, the technique rivalled the accuracy of industry-standard, high-performance liquid chromatography for ee determination.
- Science Advances 7, eabg5381 (2021). doi: 10.1126/sciadv.abg5381
|Kanazawa University (KU), Japan||0.82|
|Okayama Prefectural Police Department, Japan||0.09|
|Nagoya University, Japan||0.09|