Ayahuasca: alkaloids, plants & analogs
Section 1 :
Harmala alkaloid interconversions
Converting Harmine to Harmaline
[Palladium or platinum catalyzed hydrogenation should work fine for this conversion but no presentation as such as been located in the literature. This reaction appears to occur spontaneously even in pure harmine; during storage.]
Converting Harmaline to Harmine
Synthetic harmine can be prepared by nitric acid oxidation of commercial harmaline using procedure of Iyer & Robinson 1934.
See also Shulgin & Shulgin 1997, p. 455.
Dr. Shulgin found that an old sample of harmaline (commercial reference material) had evidently decomposed into a 1:2 mixture of harmine and harmaline. [Ott 1994 and Shulgin 1994 (lecture; BPC seminar, Maui.)]
Published analyses of old samples of plant material have also suggested a conversion of harmaline into harmine over time.
It is also claimed by Shulgin and many others that, whether from synthetic sources or via botanical purification, it is virtually impossible to obtain harmine that is completely free of harmaline.
While it is unclear how far it is directly applicable to the alkaloids in ayahuasca, the papers of Cassady and associates [1], investigating Virola cuspidata, may be of interest. In it they described experiments in which refluxing 6-Methoxytetrahydroharman in water for 8 hours and concentrating resulted in partial conversion to 6-Methoxyharman and 6-Methoxy-harmalan.
The fully aromatic compound has greater activity than the other two and it has been proposed that the prolonged boiling observed in the snuff preparation may play a role in this regard.
Such facile interconversion between such related β-carbolines has been mentioned as a potential source of misidentification during plant analysis.
Converting Tetrahydroharmine to Harmaline
Tetrahydroharmine can be converted into harmaline by dissolving 2 grams in 150 cc of acetone, cooling to -10°r; C and oxidizing, by gradually adding 4 grams of very finely powdered permanganate. The oxidation is said to be gradual. Allow the reaction to proceed until the permanganate has been completely decolorized. Purify by recrystallization as is discussed elsewhere here. Do this several times to remove the manganese. This reaction came from Perkin & Roberts 1919, on page 961.
Converting Harmaline and/or Harmine to Tetrahydroharmine
Harmaline or harmine can be converted into tetrahydroharmine by reduction of either in an alcoholic solution by the action of sodium.
Alternately; (example): 5 grams of harmaline, dissolved in 100 ml of water and 20 ml of hydrochloric acid is first heated to boiling and then 300 grams of 3% amalgam is added in three portions. This is done with further additions of hydrochloric acid so that the solution remains strongly acidic. The reaction may be observed by the changing of the yellow color of the harmaline hydrochloride into the colorless tetrahydroharmine hydrochloride. When the solution is cooled, tetrahydroharmine separates in colorless crusts. This should be dissolved in hot water, precipitated with ammonia and the free base recrystallized from methanol to give bunches of needles. The mother liquor will also yield more crystals and a total yield of around 90% is possible in theory. From Perkin & Roberts 1919, on page 961.
Shulgin & Shulgin 1997, pages 584-585, reduced harmaline using Platinic oxide and Sodium borohydride in an acidic aqueous solution using an argon atmosphere.
Harmaline has also been reduced to THH with Zinc & Hydrochloric acid. See Siddiqui et al. 1983 for the procedure. (This should also work for harmine)Siddiqui et al. 1983 found that addition of NH4Cl prior to basification with Ammonia increased the yield for this reaction from 50% to around 80% (by preventing the precipitation of Zinc hydroxide)
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