I have recently been made aware of the dangers of Jequirity bean bracelets. See the attached file (click on the link above) for more information.
This made me think of writing a blog posting on the chemical Abrin, the active ingredient (poison) in the bean. However, on doing some research, from the chemistry point of view I was disappointed.
Image kindly reproduced according to the licence at: http://en.wikipedia.org/wiki/File:Abrus_precatorius_pods.jpg
Why? Well, Abrin (and Ricin that it is very similar to) are indeed poisons – this bit did not disappoint me, indeed, it made me aware of a poison that I had not come across before. But both substances are complex proteins and not, as I imagined simple chemicals.
They work by attaching themselves to a carbohydrate on the cells surface, where they can then enter the cell and inhibit protein synthesis. The lethal does for an adult is only around 300ng, making it very toxic.
This image of Ricin has been kindly reproduced according to the licence at: http://en.wikipedia.org/wiki/File:Ricin_structure.png
As I said – interesting but not that much to do with Chemistry.
To make up, I thought I would write a posting on another poison tomorrow, cyanide – Which chemically, is far more interesting that Abrin – so watch this space.