Blogging a crystal structure a day in 2014


Contributed by

David Turner

Don't Panic – Valium / Diazepam

Our latest post from Dr Dave Turner.

What does it look like?

Image generated with Crystal Maker software

Image generated with Crystal Maker software

What is it?

Inspiration for compounds to include in the Crystallography365 blog can be tricky and, in my experience, tends to reflect my mood when coming up with the next topic. The structure that leapt to mind today was valium – read into that what you will.

Diazepam, originally sold under the name valium since 1963 (and still commonly known as this), is a drug used to treat a variety of conditions such as anxiety, panic attacks, muscle spasms and opiate withdrawal amongst others. Diazepam is a member of the benzodiazepine family of psychoactive drugs which interact with the GABA neurotransmitter. The core structure of these drug molecules is the three rings that can be seen in the left-hand picture.

Crystals of diazepam are held together primarily by weak interactions between adjacent molecules in the absence of any charged groups or strongly polar, complementary functionalities.

Where did the structure come from?

The structure was determined and published in the Journal of the American Chemical Society in 1972 (A. Camerman and N. Cameran, J. Am. Chem. Soc., 1972, 94, 268-272), when the full range of properties of the drug was coming to light. Understanding the geometrical structure was important to determine if and how the stereochemistry of the molecule influenced its biological behaviour. Structural determination allowed comparison with other drugs with similar properties and characterisation by crystallography remains a key part in drug design.