Posted on June 23, 2012 by Mark Foreman
I have already written a little about one of the toxins which some toads make, now we should think about the ring at the top right of the molecule. I think it will be aromatic, because of the fact that we have a flat unsaturated ring which has six pi electrons in it. Here is a picture of the two main resonance forms.
Resonance forms for the aromatic ring in the toad toxin
It is important to note that the toxins in toads do vary a lot from one species to another.
Filed under: toads, Uncategorized | Leave a Comment »
Posted on June 8, 2012 by Mark Foreman
I was informed by one of my PhD students that a place in Sweden is sponsoring toads, the idea is that you pay a fee to support a toad. As a result the nuclear chemistry and industrial materials recycling sections of the department of chemical and biological engineering are considering if they should have a whip round and then sponsor a toad.
Now before we get going toads have had a bit of a raw deal, they get a bad press which they frankly do not deserve (at least not always). For example they get blamed for giving people warts, and toxic mushrooms are called “toadstools” (why can they not have sofas or armchairs ?) and why are driving test examiners compared with toads ? You might argue that this web page is biased against toads and is an example of hate speech against toads.
But I would say that the cane toad is a nasty little so and so who needs to be put in his/her place, maybe the other toads should take the cane toad behind the potting shed and reeducate it a little.
It is important to note that all the toads have toxin which protect them, one of the toxins which the common european toad has is a cardiotoxic steroid. This is an interesting molecule called bufotalin which has been isolated from a range of different toads. One paper (A.Kalman, V.Fulop, G.Argay, B.Ribar, D.Lazar, D.Zivanov-Stakic, D.Vladimirov, Acta Cryst., 1988, C44, 1634-1638) used the Chinese toad Ch’an Su as a source of the toxin. The molecule is a steroid which has an additional six membered ring group attached. The additional group is an aromatic ring which is in disguise. Here is a molecule of bufotalin.
Bufotalin a toxin from a toad
I will write more about the “toad toxin” later
Filed under: Chemistry, steroid, toads, toxin | 1 Comment »