vecktor said:
I have been interested in the extraction artifacts of mescaline for a while, the alleged 2,6 dichloromescaline was a reported extraction artifact, and I wonder about the conversion of mecaline to tetrahydroisoquinolines as a consequence of reaction with free aldehydes during cactus extraction.
V
These extraction artifacts are a potential issue with both tryptamines and phenethylamines.
I seem to recall Shulgin saying as much in the first chapter of his book on isoquinolines, pointing out the parallel between the cyclization of PEA -> THIQ & Tryptamines -> beta-carbolines
also see:
The Pictet-Spingler Reaction and Biogenic Tryptamines: Formation of Tetrahydro-ß-carbolines at physiological pH. JC. Callaway, J. Gynther, A. Poso, J. Vepsäläinen and MM. Airaksinen
J. Heterocyclic Chem. 1994:31:431-435
Racemic and Diastereoselective Synthesis of Aryl and Heteroaryl Tetrahydroisoquinolines via the Pictet-Spengler Reaction
Sylvain Aubry, Stéphane Pellet-Rostaing, René Faure and Marc Lemaire
J. Heterocyclic Chem., 43, 139 (2006).
Pictet-Spengler reaction
It gets into something that perplexes me a bit. I'm often wondering whether
any analysis is completely free of bias due to chemistries that occur between the state of matter in the plant and what's observed on analysis. Kind of a Heisenberg Uncertainty Principle of natural product chemistry.
A couple examples come to mind:
- The observation of the ratio of epimers of lysergamides in LSA containing seeds. Does it represent what is in the plant or is it simply the reflection of equilibria under the extraction and analysis conditions?
- The belief by some that perhaps all the content of MG seeds exists as the d-hydroxyethylamide, and it is the extraction/purification/testing procedures which then produce the APPARENT result that the alkaloids are ergine, isoergine, and maybe still some hydroxyethylamide.
There's no doubt that one has to be careful making definitive statements about what the actual chemical composition is of plants. However, I also think it's somewhat a cop out to suggest that
all measurements are highly biased by the techniques used to analyze samples simply to defend various points.
This debate is a traditional one of sorts. When
Richard Willstätter invented paper chromatography independently of
Mikhail Tsvett at the beginning of the 1900's, they argued the point.
Willstätter, a student of Adolf von Baeyer (Nobel Prize 1905), went on to win the Nobel Prize for Chemistry in 1915 for his study of the structure of chlorophyll and other plant pigments.
Willstätter's student and close friend was Arthur Stoll who subsequently went on to discover ergotamine and lead Sandoz where he was Albert Hofmann's boss, thus Hofmann's scientific genealogy is top notch to say the least. I would even propose that without it, Hofmann may not have had the subsequent skills he demonstrated.
I'm currently reading Willstätter's memoirs. Sorry that I've strayed from the topic at hand.