It seems this conversion actually happens and has been documented in a couple of places. (edit: one home experiment with TLC testing seems to show no conversion happening)
McIlhenny et al 2009. Direct analysis of psychoactive tryptamine and harmala alkaloids in the Amazonian botanical medicine ayahuasca by liquid chromatography–electrospray ionization-tandem mass spectrometry. Journal of Chromatography A, 1216, 8960–8968
and:
Callaway et al 2005. Phytochemical Analyses of Banisteriopsis Caapi and Psychotria Viridis. Journal of Psychoactive Drugs Volume 37, Issue 2, 2005
Interesting enough, recently I tested some black caapi vine, just methanol soak, and it didnt seem to have any detectable harmaline. When I tested an extraction from the same vine, it did have detectable harmaline. Would be good to test this again, experimenting with different variables in the experimentation (like for example boil homogeneized plant material for longer or less, with acid or no acid, etc. McIlhenny et al never seemed to have published the other data about this interconversion of alkaloids. Edit: I tested this again with white caapi and the same happened, check caapi analysis thread. One more potential confirmation that this interconvertion is actually happening.
Some questions: Is the extended boiling done by indigenous people purposeful, because somehow intuitively or experientially they felt that brews with higher THH content was more beneficial? Shoud this be an invitation for extended boiling? Is it worth the energy spending in these days where ecological impact is an issue? Maybe the boiling also breaks down other components instead of just converting harmalas, so whats the cost/benefit like?
And some more chemically related: Due to the chemical bonds, is it less favourable for harmine to turn into harmaline, than to harmaline turn into THH ? Can one get an "optimum" ayahuasca alkaloid content by messing with cooking time/storage?
Regarding storage, while McIlhenny paper says storage affect alkaloid content, callaway paper says it did not affect content of one sample they monitored over 80 days, which only changed pH (becoming more basic) and started to ferment after a while, but alkaloid content stayed the same. Both papers seem to agree boiling does make that conversion, and no extra acid seemed to have been added on any brew.
McIlhenny et al 2009. Direct analysis of psychoactive tryptamine and harmala alkaloids in the Amazonian botanical medicine ayahuasca by liquid chromatography–electrospray ionization-tandem mass spectrometry. Journal of Chromatography A, 1216, 8960–8968
The data also suggest that prolonged heating/boiling of the ayahuasca preparations leads to inter-conversion of some of the components. This appears to occur to a significant degree for the changes seen in THH, harmine and harmaline levels between samples undergoing further heating to attain higher concentrations of the components (See Table 3). This phenomenon, an apparent acid-driven chemical reduction of harmine-to-harmaline-to-THH, has also been reported by Callaway et al. [28] and constitutes another source of potential variability of results among ayahuasca preparations.
(...) Solutions of the target compounds in water were stable for the period of time examined (6 months) when stored at −20 ◦ C and kept from exposure to light by use of amber vials. Similarly, ayahuasca samples were stable for the same period of time when retained under the same conditions. However, preliminary data (not shown) indicate that the ayahuasca preparations are susceptible to degradation and compound inter-conversion through
prolonged exposure to room temperature conditions and these changes are accelerated by exposure to light (data not shown) and changes in pH that occur as the preparations age. These and related data will be the subject of a forthcoming publication.
and:
Callaway et al 2005. Phytochemical Analyses of Banisteriopsis Caapi and Psychotria Viridis. Journal of Psychoactive Drugs Volume 37, Issue 2, 2005
The average ratio of THH to harmine in the vegetals (traditional brews) was consistently near 1:1, from all sources (table 2), while this ratio was closer to 1:5 in a large survey of source plant material. It is presently unclear whether harmine and harmaline are being chemically reduced to THH during the acidic process of decoction, or if THH is simply more stable than the other two harmala alkaloids, which may be lost through decomposition, or a combination of both processes.
Interesting enough, recently I tested some black caapi vine, just methanol soak, and it didnt seem to have any detectable harmaline. When I tested an extraction from the same vine, it did have detectable harmaline. Would be good to test this again, experimenting with different variables in the experimentation (like for example boil homogeneized plant material for longer or less, with acid or no acid, etc. McIlhenny et al never seemed to have published the other data about this interconversion of alkaloids. Edit: I tested this again with white caapi and the same happened, check caapi analysis thread. One more potential confirmation that this interconvertion is actually happening.
Some questions: Is the extended boiling done by indigenous people purposeful, because somehow intuitively or experientially they felt that brews with higher THH content was more beneficial? Shoud this be an invitation for extended boiling? Is it worth the energy spending in these days where ecological impact is an issue? Maybe the boiling also breaks down other components instead of just converting harmalas, so whats the cost/benefit like?
And some more chemically related: Due to the chemical bonds, is it less favourable for harmine to turn into harmaline, than to harmaline turn into THH ? Can one get an "optimum" ayahuasca alkaloid content by messing with cooking time/storage?
Regarding storage, while McIlhenny paper says storage affect alkaloid content, callaway paper says it did not affect content of one sample they monitored over 80 days, which only changed pH (becoming more basic) and started to ferment after a while, but alkaloid content stayed the same. Both papers seem to agree boiling does make that conversion, and no extra acid seemed to have been added on any brew.