Clifford Todd explains (p44 line2),
"1 Our first analysis on some materials fromI looked up the structure of piperine ...
2 Alexandra Grove showed us the presence of a material
3 called piperine. It later transpires that that is
4 simply something that is contained within black pepper."
To see why, you need to be familiar with the structure of ecstacy, and see how it compares with piperine. In the diagram, the lower structure is ecstacy (MDMA)
A bit of googling quickly takes us to the drug site Erowid (very useful site for the study of chemistry, btw), which has a couple of pages dedicated to converting pepper to piperonal.
Piperonal, as is obvious from the wikipedia link, is a starting material for the synthesis of ecstacy.
This is depicted in the diagram below; the piperonal to MDMA transformation is seen
Further thoughts on hydrogen peroxide/piperine as an explosive mixture
Throughout the Hearing Transcripts (I've only made a close study of Coroner's Inquests into the London Bombings of 7 July 2005 Hearing transcripts – 1 February 2011 - Afternoon session) the purity of the piperine isn't made clear. Nor is it made clear why piperine is particularly effective, when mixed with hydrogen peroxide, as a bomb. The idea of a hydrogen peroxide and piperine bomb is something called a Sprengel explosive.
Quoting from wikipedia,
"Sprengel explosives are a generic class of materials invented by Hermann Sprengel in the 1870s. They consist of stoichiometric mixtures of strong oxidisers and reactive fuels, mixed just prior to use in order to enhance safety. Either the oxidiser or the fuel, or both, should be a liquid to facilitate mixing, and intimate contact between the materials for a fast reaction rate."Applying this to the purported hydrogen peroxide/piperine mixture; supposedly hydrogen peroxide is the 'strong oxidiser' and supposedly the piperine is the 'reactive fuel'. As for 'stoichiometric', this means there is the necessary amount of hydrogen peroxide to piperine in order to oxidise the piperine to carbon dioxide, water and nitrogen dioxide.
The balanced equation is
2 C17H19NO3 + 85 H2O2 → 34 CO2 + 104 H2O + 2 NO2From the balanced equation we can work out the proportions of piperine to hydrogen peroxide
|2 x 285.34||85 x 34||theoretical calculation|
|570.68||2890||assuming 100 % pure hydrogen peroxide|
|1||5||assuming 100 % pure hydrogen peroxide|
|1||10||assuming a 50 % w/w hydrogen peroxide|
As far as I'm aware, we don't know the concentration of the hydrogen peroxide used; depending upon the concentration of the hydrogen peroxide, the ratio of piperine to hydrogen peroxide would be 1 g to 10 g. Does this sound like a thick slurry to you? It certainly doesn't to me.
A thicker slurry needs more concentrated hydrogen peroxide with all of the associated lack of credibility. If the slurry is thicker without the necessary hydrogen peroxide present to oxidise it, the chances of finding traces of piperine post explosion increases.
The choice of hydrogen peroxide as an oxidiser in a Sprengel explosive is a poor choice due to reasons discussed elsewhere (difficulty in obtaining the appropriate concentrations, instability, etc); but why choose piperine as the fuel?
There aren't any obvious reasons. It is a fuel but I don't get the impression it is a particularly reactive one.
Thinking about the two competing hypotheses: drug factory or bomb factory; there is insufficient evidence to conclude one way or the other. But the idea that it was a drug factory is a sensible and viable hypothesis.
Lastly, I wonder if anyone has tried to repeat the chemistry? Extration of piperine from pepper followed by oxidation with hydrogen peroxide, with a view, perhaps, to making piperonal?