I've posted about substituted ampehetamies in this plant and a closely related species, A. berlandieri a number of times and have looked closely at related pathways to try to determine where the original skeleton is coming from...my ideas so far are:
1)Some sort of reduction step from ephedra alkaloids (which are found in other plants, but unfortunately not detected in these...not sure if the extraction procedure they used would pull these out, but I think they should have shown up if they were there...so probably not this)
2)An enzyme with a decarboxylase/methyltransferase combined activity...it could use PLP to decarboxylate phenylalanine (or tyramine) and then use the delocalized lone pair to use the alpha-carbon as a nucleophile for attack on SAM or THF etc...I like this one simply because PLP-dependant enzymes kick ass
3)Transaminase activity to form amphetamine skeleton from a related phenyl-2-propanone (similar to reductive amination, only the transaminase uses the amine version of PLP (there it is again
), PMP as the amine donor, water is lost. This type of activity has been documented in Phe and Tyr, why not the P-2-Ps?
I do have a couple other putative enzyme mechs, but they lack the supporting related enzyme activities, and really don't sound as good...
Begin with the dissolution of superfluous matters
So that desire and consciousness are free