Decomposition of THH into harmine in CHCl3 solution

[absinthoman]

Hi everybody,

I'm a new member here but I've been reading for a couple years. I've found a pretty good article yesterday and I wanted to share this with you guys. Maybe it is something some poeple aleready know but here it is:

While studying THH by NMR they discovered that the THH in chloroform solution was decomposing quantitatively (full conversion) into harmine after 15 days. They say it might be decomposing by a radical mechanism.

Here is the ref: Tetrahedron 2002, 58, 6185-6197. (they talk about this specific decomposition at p. 6195)

My question now is: does this decomposition mechanism involves harmaline intermediate? It would be logical. If it's the actual case, that means we could transform harmine/harmaline mixture into 100% harmine by just dissolving this mixture in CHCl3 and let it stand for 15 days before evaporating... What do you guys think??

This could be easily verified by endlessness with the help of his MS or just by having pure sample of harmine and doing some TLCs. Anybody interested???

 

[absinthoman]

Nobody interested?

 

[endlessness]

Interested, but busy

Thanks for sharing the info, Ill get back to this.. Feel free to continue the discussion. What possible interest do you see in this, any uses, or just curiosity, or?

 

[InMotion]

That's actually a bit curious!

It's hard to imagine a hydrogen abstraction occurring specifically at that point but it must be a desire-able transformation. The only oxidizing agent present would seem to be diatomic oxygen. I'd have to crunch some numbers but it's also possible that a chlorine radical propagation from UV light(photolysis) may occur as well. Err whats the equation E = h*c/lambda. Any chance the full article could be uploaded?

I suppose this is also very important to know of when working with harmala isolates. If it happens in D.C.M. could probably happen in anything. Could be a nice little technique for caapi extractions as well to favor harmaline.

 

[DDanimal]

This is really interesting to me, because I was just reading about the formation of THH during boiling of caapi.

I have long wondered about THH and its presence in caapi brews. Some analysis results indicate that caapi does not contain THH, and yet its clear that caapi tea does contain THH.

The explanation appears to be that THH is formed from harmaline and harmine during the cooking (boiling) process. Acids and antioxidants in the caapi vine provide the hydrogen atoms needed to form THH.

From Calloway, 2005, Journal of Psychoactive Drugs:

"In Situ Production of THH
The average ratio of THH to harmine in the vegetáis
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 (i.e., B. caapi, see Callaway, Brito & Neves 2005 in this issue). 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 maybe lost through decomposition, or a combination of both processes. Figure 1 illustrates a likely chemical pathway for the conversion of both harmine and harmaline to THH through reduction under acidic conditions."

 

[endlessness]

This is an older thread that may be of interest

Conversion of Harmine->Harmaline->THH by simple boiling (and storage?) - DMT Discussion - Welcome to the DMT-Nexus

 

[DDanimal]

hi

do you have that paper?

I will try to obtain it.

Jafrine, a novel and labile β-carboline alkaloid from the flowers of Tagetes patula ☆
Dedicated to the fond memory of Professor Salim-uz-Zaman Siddiqui FRS (1897–1994), the founder director of H.E.J. Research Institute of Chemistry, University of Karachi

Shaheen FaiziCorresponding author contact information, E-mail the corresponding author,
Aneela Naz

H.E.J. Research Institute of Chemistry, University of Karachi, Karachi 75270, Pakistan

Abstract

An inherently unstable and structurally novel tetrahydro β-carboline alkaloid, (+) jafrine (1) was isolated from the petroleum ether extract of Tagetes patula flowers. Its structure and stereochemistry has been determined with the help of spectroscopic analysis and the synthesis of racemate, (±) jafrine starting from available (±) tetrahydroharmine (2). The effect of solvent polarity on the ratio of amide rotamers of jafrine during NMR studies is discussed. The transformation of jafrine as well as 4-N-acetyl tetrahydroharmine (3), into 2-acetyl tryptamine derivatives by auto-oxidation was observed and its detail is presented. This process may be used as a synthetic tool for the preparation of tryptamine derivatives.