Solubility of alkaloids in acid/base

[Jox]

HI all at nexus,

I did this extraction:

1 soaked Caapi in vinegar 5% for one hour.

2. added NaOH solution.

3. washed out with destilled water.

the formula
CH3COOH + NaOH = CH3COONa + H2O

for neutralization I calculated in this way

CH3COOH = 60
NaOH = 40

I was calculating molecular mass, so then I did the proportion:

40 NaOH : 60 CH3COOH = x NaOH : (la cantitad de vinagre with Caapi)

Thus I would calculate the ammount of NaOH that I need for the neutralization.

I don't have access to ph indicators, so I used 50ml x 5 g of NaOH, as per extracions on this forum.

The problem is that in one extraction it didn't go well, in other 4 I got good yield.

I would like to understand the chemical mechanism behind it, so If things go wrong I can decide what to do.

The questions are, chemically speaking:

What is happening to alkaloids in vinegar or acid? chemically speaking, what will be the equation?

thanx a lot
Jox

ps. btw I have been a new member for some 2 years? How do I get to be a member?

 

[Jox]

Why is nobody replying? Should it be placed in some other section of the forum?

Jox

 

[benzyme]

all you wrote are some equations for making sodium acetate salts, nothing to do with alkaloids.
what you need to find out are the pKa's of the alkaloids of interest (terminal amine pKa's), that way you can decide what pH ranges to use. don't try to figure out stoichiometric/gravimetric quantities, because you have no idea what the concentrations of alkaloids are.

 

[Jox]

Hi Benzyme,

thanks a lot for answering.

If you have time to answer my questions it will be greatly appreciated:

The reason for the equation and calculations, was for neutralization of the acetic acid: I was soaking Caapi in 5% acetic acid, and not cooking i water. So I used the calcualted amount of NaOH to neutralize the acid. Then I would washi it in destilled water.

My tec. is based on the extraction of Ibogaine: vinegar + ammonia + acetone + Hcl.

I thought of useing the same for Caapi extraction and do this: vinegar + NaOH + destiled water for wash out.


What do you think?

thanx Jox

 

[benzyme]

I think you're not getting the point of extraction.

neutralizing the acid does nothing but leave water and inorganic salts, and doesn't do anything for alkaloids, which will likely still be in the water.

the whole point of acid/base extraction is to protonate and deprotonate the amine group of alkaloids, so you can facilitate the migration of the alkaloids from an aqueous phase to an organic (nonpolar) phase; this separates alkaloids from sugars, fats (after a defatting step), and other unwanted plant compounds. to do this, you shift the pH from acidic to basic, not neutralization.

 

[Jox]

Hi Benzyme,

for a second I felt yeeew, I am screw up, but the tecs i didn't invent on my own:

- for harmalas I used this:

Enoons Cold Caapi Tek - DMT-Nexus Wiki

wiki.dmt-nexus.me

- and for Ibogaine I used Chris Jenks extraction, that has video and pdf manual.

Since I have experience with Ibogaine extractions, I used the same for harmalas, only changing ammonia for NaOH, also suggested in the Enoons tec.

Yet I would like to know the chemistry behind it, so if anything goes wrong I could correct it.

If you have the time to elaborate please do so.

thank you Jox

 

[Enoon]

I can't give you chemical details because I'm not up to par on the matters... but in layman's terms:

supposing that the alkaloids in the plants are in some kind of salt form, by soaking in water you will create a solution of these salts. By adding vinegar you facilitate this. The end-result of a vinegar soak is that you have your alkaloids in dissolved salt-from dissolved in the water.

when you basify you not only neutralize the acid. Once the excess acid (vinegar) is neutralized adding more base will change the salt-form of the alkaloids to freebase form, which no longer are soluble in water and thus precipitate out.

There is no need to calculate exactly how much base you need for this process, since you will be washing your product in the end anyway. What you do generally is take high pH value solution (saturated sodium carbonate solution or water with lots of NaOH [careful]) and start adding this bit by bit.

If for example using sodium carbonate you will see bubbles forming from the chemical reaction of the vinegar and the sodium carbonate. With NaOH no bubbles but what you should see after a while is that stuff falls out. You can have crystals form or just flakes slowly sinking to the bottom.

When no more stuff sinks to the bottom you can stop adding base.

If you had bad results, you either didn't add enough base or there were no alkaloids in your brew to begin with.

I think 1 hour soak is very little, but if you get good results perhaps I waited longer than I needed to.

 

[Jox]

Enoon,

thank your for responding. I got better the reason why one pull didn't work.

But 1 h is enough. I do 3 pulls and 3rd has no any alkaloids, so I assume it is enough, even though I still do 3rd just in case...

I love this tek: it is quick, no energy waste...

So the idea is to add a lot of NaOH, more then just to neutralize the vinegar, becaouse some a lot goes to that, it seems I was not adding enough then.

Jox

 

[benzyme]

exactly.

you want excess hydroxyanions (-OH) in solution, to (deprotonate) neutralize the positive charge on the amine of the alkaloid of interest, and this is relative to that amine's pKa.

 

[Jox]

Benzyme,

is it safe to say that I can add arbitrarily NaOH, I am using 5g x 50 ml.

If not how would you calculate the amount of NaOH for this situation?

and maybe we can add it to the tek in wiki.

thanks
Jox

 

[Infundibulum]

Benzyme,

is it safe to say that I can add arbitrarily NaOH, I am using 5g x 50 ml.

If not how would you calculate the amount of NaOH for this situation?

and maybe we can add it to the tek in wiki.

thanks
Jox

Depending on what you're extracting you might add too much base, and harm the alkaloids you're trying to extract. DMT is often fine at extreme pH values, while other alkaloids break down. The safest way to pH really is to use a good, properly calibrated pH meter. But if you want to add lye by eye then do remember that the pH scale is logarithmic. As a rule of thumb, in neutral pH water, 40grams of NaOH per litre raise the pH to 14; 4grams of NaOH raise the pH to 13; 0.4 grams of NAOH raise the pH to 12, and so on.

Obviously a water mixture with alkaloids, plant acids, added acids and whatnot will not behave like clean water when it comes to responding to pH changes. That is why you really want a pH meter if you plan to do even half-serious titer work (as you describe in your OP). All the equations in the world cannot help you one bit in calculating how much NaOH to add in a complex plant extract mixture.

 

[Enoon]

if you stop adding when no more alkaloids drop out I doubt you will enter the realm of harming the alkaloids. Not unless you are adding grams of NaOH.

I usually did it like in Gibran's tek (Easy Caapi Vine Alkaloid Extraction Guide - DMT-Nexus Wiki): Add about 5g NaOH to 50ml water and then slowly add that to the brew. If you didn'T get to the point where the alkaloids stopped dropping out, repeat.