Monday, 8 April 2019

The Significance of Optical Isomers

Firstly, sorry the blog has been a bit dead - I've been flat out with work and life commitments!

Optical isomerism is a discovery made by French Physicist Jean-Baptist Biot. It essentially means that any carbon atom in a molecule which is bended to four different groups may from two different versions of that molecule (enantiomers).

These two  which are non-superimposable mirror images of each other, as shown by the example below; the infamous thalidomide:

Image result for thalidomide


Thalidomide was a drug which was originally licensed in 1958. Its primary use was to treat morning sickness in pregnant women. It was not known that thalidomide was optically active. The R enantiomer (shown above) was useful in treating morning sickness, whilst the S enantiomer led to the birth of babies with shortened limbs. For this reason, thalidomide's license was withdrawn in 1961.

Another, less extreme example of optical isomerism is carvone:

Image result for r and s carvone

R-carvone is used in chewing gum, because is has the taste and aroma of spearmint. S-carvone however, has a radically different aroma and taste - caraway (similar to dill and parsley). 

Imagine a batch of chewing gum made with a racemic mixture (50:50 of each enantiomer) of carvone.... eughhhhh!

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