There is a fascinating unanswered question that I had to ask myself a little while ago. It is a question that, if ever answered accurately, just might throw the entire area of the pharmacology of harmaline into a delightful disarray. I received a small quantity of documented seeds of Syrian rue and I was curious to see, in my hands, what its alkaloid content was. This is, after all, a well known source rapidly increasing in popularity as the inhibitor component of ayahuasca. So I ground a few of them up in a mortar under DMF and carbonate, spun down the extract, dissolved a drop of it in a milliliter of 90:10 toluene/butanol, and shot a microliter into the GCMS. As expected, there were two major peaks, and an intriguing scatter of small things. The spectrum of first was clearly that of harmaline, and of the second, that of harmine. The literature is correct.

Then, to tidy up a bit and make absolutely sure of the relative retention times, I decided to run standards from my reference collection. Reference harmine gave the second peak with identical retention time and MS spectrum. It was when I injected a sample of my reference harmaline that I got my surprise. Here, a sample of E. Merck AG, Darmstadt yellow crystalline material labeled Harmalinhydrochlorid, was very much looking as if it was a mixture of about two parts harmaline and one part harmine. Only 70% pure? Wow.

Three explanations popped into mind. (1) Maybe the harmine was being generated from harmaline, somehow, in my analysis. So I tried another reference sample, one recently purchased, and it gave a single peak. So it was not an artifact arising from some quirk of my analytical process. (2) Maybe the Merck sample, which I had obtained in the early 1960's (and of course I had no way of knowing how old it was when I got it) had come from plant sources, maybe even P. harmala itself. Maybe the analytical tools at the time were inadequate to detect and identify this amount of harmine as an impurity. This is not comfortable, in that these two alkaloids were first isolated, and separated from one-another, from plant sources some 150 years ago. I am sure my sample is not that old. I am not sure that even E. Merck AG is that old. The tools of analysis have been around a long time. Anyway, I wrote to them, and they answered me with the elliptical comment stating that they had never had harmaline in their catalog, only harmine. And thus, they would have no way of knowing what was in the bottle. Of course they could have distributed research samples of many things, of stuff that was never in their catalog, but by replying in this way they are absolved of all guilt. And of all legal responsibility as well, of course. OK.

This leaves (3). Maybe over the years, harmaline spontaneously loses a molecule of hydrogen, and becomes harmine. Not an easy thing to reckon with, chemically, but I am running out of possibilities. I was led to a comment that had been once made by a quiet hero of mine, Bo Holmstedt in Sweden, concerning the analysis of an ancient sample of plant material from Banisteria caapi (now known as Banisteriopsis caapi). The herbarium specimens he was looking at had been collected by the 19th century plant explorer Richard Spruce in the Rio Negro area of South America and had, after a few years of storage in a moist and mildewy hut a few miles down river, been rediscovered and sent on to the Kew Botanical Museum where they had quietly rested for over a hundred years. When Holmstedt worked them up some 30 years ago, he reported that the alkaloid content was 0.4%. This was virtually identical to a newly collected, botanically verified specimen of Banisteriopsis caapi which he analyzed at the same time and found to contain 0.5% alkaloids. The latter material contained, as described by many authors, the main alkaloids harmine, harmaline and tetrahydroharmine. By contrast, the alkaloid content of the Spruce material consisted exclusively of harmine. It is open to question whether the samples collected by Spruce in 1853 originally contained only harmine or, perhaps more likely, that harmaline and tetrahydroharmine have with time been transformed into the chemically more stable aromatic b-carboline harmine.

How can this enigma be answered? Put away a sample of pure harmaline, with its spectral identification, onto the shelf for 50 or 100 years, and then re-analyze it? Who knows, but what might be needed for this conversion is heat, or a bit of iron catalyst, or some unknown species of South American mold. Acid is certainly known to promote this oxidation. It would be very much worth while to answer this question because some, perhaps much, of the results of human pharmacological studies that involve harmaline as a metabolic poison, may be influenced by the independent action of harmine as a harmaline contaminant.
Shulgin;TIHKAL

If the caapi vine can offer us any insight on the stability of harmala alkaloids in plant matter over time, I'd say you should be fine.

From personal experience, I have had poorly stored seeds for many years, and they remained active...

-eg