A/B/A Harmaloid centrifugal degunking

[Elrik]

I observed an unexpected phenomena that I havent ever seen explicitly mentioned so I figured I'd briefly share.
While doing microscale experiments on harm[al]ine purification I got impurities to precipitate when they really shouldn't have. It got my attention enough to try a dedicated test of the effect.
ca. 200mg of impure red harmaline/harmine•HCl was made into 20 ml solution with distilled water, filtered, centrifuged, and refiltered. It was free of solids. I based it to pH 13+ with a 5ml aliquot of NaOH (aq) and centrifuged. The liquid was discarded and the dark tan solids were dissolved in 6 ml of 5% acetic acid [a clear excess]. The solution was centrifuged and a quantity of nearly black gunk separated out. The liquid was then mansked to make beautiful light golden yellow crystals I'd be proud to eat.
What I suspect is that a strongly colored alkaloidal impurity that is less soluble in vinegar than harmaline acetate was pushed out of solution when the alkaloid solution was made so concentrated. It looked like it did the job of several manskes.
Has anyone else observed that phenomena?

 

[Loveall]

My favorite candidate would be that you are getting harmalol (endlessness may be laughing right now if he sees this ). You can check by keeping the discarded basic liquid. Acidify that to the same pH as you had the redisolved harm(al)ine. Centrifuge, if you get the same gunk but in much larger quantities you are probably looking at harmalol. If you take the solution to a pH of 9 (near the isolectric point of harmaolol) and even more precipitates after centrifuge then you are likely looking at harmalol I think.

Harmalol will still be water soluble in a basic environment. You may have kept some in your first alkali precipitate since some liquid came with it. Therefore, another test is to thoroughly rinse the harma(li)ne in the filter with fresh alkali liquid. That should rinse out the harmalol. After a thorough rinse out, you should have none or very little coming through the subsequent acidic centrifuge.


Maybe it is not harmalol, but you can run the experiments above to see if it is consistent with it. Most of the harmalol is in the liquid of the first basing step, after discarding that, one has residual harmalol left (but a little bit can give a lot of red color). Harmalol also fluoreces red at high pH and green as the pH is lowered. Check for this in the basic filtered water before discarding it.

Some of this was covered in this thread. Unfortunately, some of the pictures were lost after a Nexus chat outage.

If you are really interested you can do something like this:

1) extract rue seeds, decant, filter
2) basify, filter, keep the alkali water
3) Filter the alkali water well
4) Add 30% NaCl and IPA, two layers will form
5) Bring the water to the pI of harmalol. As you do this under UV you should see the red fluorescence moving to the IPA and becoming green fluorescence.
6) Pull the IPA, it contains some water and salt unfortunately.
7) Evaporate the IPA
8 ) Pull with dry IPA, salt should remain behind this time (note: I have never gotten this far).
9) Final dry to obtain harmalol. It is typically gunky/flaky. You may be able to salt it by dissolving in vinegar and drying. However, once dry it may degrade and not redisolve so this may not be possible.

Or something along these lines. I think we dump maybe 1% of harmaolol from seeds (a rough guess) when we do rue extractions. Also, you can go straight for harmalol by extracting the seeds in alkali water first.

 

[blue.magic]

I observed this too and always wondered what the precipitate is.

Now I always do A/B/A with lots of filtering, decanting and washing in between before proceeding to Manske. The crystals are so much purer.

What helps with purity even more is to filter through Celite before Manske-ing. Sometimes the solution is so clear the crystals refuse to grow without scraping the glass.