fractional distillation of cactus/methanol extract

[toadvenom]

If a Shaman in Peru extracted 176.5g of dried San Pedro powder three times with fresh methanol yielding 1.66l of solution (which was filtered through #1 filter paper using a buchner funnel and hand vacuum pump generating 50mmHG to remove all plant matter) and this Shaman then wished to reduce the volume and recover the methanol through distillation...

He might bee looking ahead (to defatting) and realize that dichloromethane is miscible with methanol but immiscible with distilled water. This Peruvian Shaman might be looking at his simple fractional distillation apparatus with it's 1000ml single neck flask capacity and wonder how he might best go about eliminating the methanol through distillation while replacing the methanol with distilled water.

He is wondering if he should first reduce the methanol through fractional distillation to a certain volume at which point he would interrupt the distillation process and add distilled water? Or should the distilled water be added before fractional distillation begins? What might be the ratio of water to methanol? If it were 4:1 that would create a total volume of 8.3l, and given the 1000ml capacity of the boiling flask, this could bee a lengthy and time consuming process!

Any suggestions for our foreign friend? He would sure appreciate any insight you might glean.

[baalchemist]

H2O should be added first to 'unmarry' the MeOH/DCM azeotrope, then the DCM will come off by itself.

[Osmium]

Did the shaman already add the DCM to the methanol? If so, how much?

When you have a few grams of stuff you want in that much MeOH it is definitely best to first distill out the bulk of the MeOH. It can be kept and reused for the same purpose again.
Once you have removed 90% or so of the MeOH add 0.5-1L of water and proceed with whatever you planned to do. Do not distill to dryness and avoid scorching the extract near the end!
You will have much less solvent volume to deal with, the MeOH can be reused, yields will be better and less DCM will be needed.

[toadvenom]

Thanks for the info. At this stage, the Shaman is interested in reducing the volume of MeOH (and replacing it with dH2O.) Regarding the DCM, it has not been added yet because he realizes it's miscible with MeOH. Sorry I didn't make that more clear. Our Peruvian friend will take your approach, Osmium. Thanks.

[toadvenom]

The Peruvian Shaman reduced the MeOH cactus extract to 178 ml (and recovered about 1.3 l of MeOH.) He is wondering what he should do with the tars that have formed in the extract?

Are there goodies trapped inside the tar? Should the tar bee completely removed from the extract or simply left alone?

From here, the Shaman would like to combine about 400 ml of dH2O to the 178 ml extract and completely distill off the remainder of the MeOH.

He would like to saturate the dH2O with salt as a further barrier to the MeOH so as to ensure that as much MeOH will be removed as possible. (36 g of salt go into about 100 ml of cold water although he doesn't think he'll use quite that much salt - maybe more like 32 g/100 ml.)

Further separation with DCM will follow.

Thanks for any help you might bee able to provide.

[monkpea]

Can I ask you to tell the shaman to set aside a small amount of your black MeOH 'goo', add it to a flask containing some sodium bicarbonate in water and (steam) distill?

Extract the distillate with a bit of DCM and evaporate to see if any mescaline comes over.

Perhaps adding some xylene to the distillation would help bring it over?


Acid base extractions of cactus produce horrid emulsions...

[Osmium]

> From here, the Shaman would like to combine about 400 ml
> of dH2O to the 178 ml extract and completely distill off
> the remainder of the MeOH.

That's not necessary. You can leave in some of the MeOH.  Remove a little more MeOH by distillation (50ml or so, under slightly reduced pressure if possible) and use a little more water later. 

How much tar/extracts are we talking about? Just a few grams or shitloads?

> He would like to saturate the dH2O with salt as a further
> barrier to the MeOH so as to ensure that as much MeOH
> will be removed as possible.

Again, I don't think it's necessary.
If you want try it out with a small amount, but I doubt this will be beneficial at this stage.

> Can I ask you to tell the shaman to set aside a small
> amount of your black MeOH 'goo', add it to a flask
> containing some sodium bicarbonate in water and (steam)
> distill?

I doubt mescaline will steam distill easily and efficiently. You will rather collect a lot of other shit.
If you decide to try to steam distill, then first acidify, distill until nothing seems to come over anymore, let cool somewhat, basify and distill your goodies. But I doubt that this will work.

> Acid base extractions of cactus produce horrid emulsions...

I still think that an A/B is the most practical way to purify the remaining goo.
Try it out with only a small part of your solution/mixture, like 50ml or so! Store the rest well-stoppered in the fridge or freezer, just to be on the safe side.
Acidify the extract sufficiently so that all amines will stay in solution and extract with a NP solvent to get rid of the tars. Maybe another NP solvent than DCM (ether, toluene, xylene) will produce better results. Repeat three times. When emusions form try to break them by filtration and with patience. Let the water layer clarify by leaving it alone for another day or two or maybe longer, leaving it undisturbed. Once the water appears perfectly clear and free of shit floating in it, separate it by removing it with a pipette or similar.
Save everything for now, we will tell you when it is time to discard anything!
Maybe some further purification can be done now by using a small amount of charcoal. Dunno, let's see what others have to say about this.

Finally basify that water, extract and fight emulsions as above. The NP layer should now contain your goodies, ready for crystallization, further purification by chromatography or whatever.

[Osmium]

Or you could try to remove pretty much all volatiles at this stage:

> The Peruvian Shaman reduced the MeOH cactus extract to 178 ml

If you have vacuum you could try to remove pretty much all volatile solvents after you basified this extract.

Then the tarball is dissolved/solubilized in an organic solvent (e.g. acetone since it will tolerate small amounts of water), filtered through celite (to separate inorganics and other insoluble shit, wash with plent yof more solvent) and the bulk of the acetone removed again. Tedious if you don't have a rotovap, I know... (***)

The residue is now taken up in a NP solvent like toluene, ethyl acetate or ether and the goodies are extracted with rather diluted HCl. The aq. HCl extract is washed once more with the same NP (add to the tarball/NP mixture), basified and the mescaline freebase extracted.

You see, there are many ways to proceed, try out whatever you want to do with a small amount first!

Whenever emulsions show up, filter the emulsion and give it some time. Also, using more diluted solutions will often speed up phase separation. Even the most stubborn emulsions can be fought with patience.

(***)
If you have chromatography equipment you can also separate the wild-ass mixture at this point.

[toadvenom]

> How much tar/extracts are we talking about? Just a few grams or shitloads?

18.5 grams, which were removed and set aside.


The Shaman started down this path when he discovered that he could perform the xylene A/B extraction:

http://www.erowid.org/plants/cacti/cacti_chemistry2.shtml

- he's got a pretty primitive "kitchen" ya know - but soon realized that this procedure is woefully lacking.

He then stumbled across a poorly written, but, highly charmed procedure posted by Fu333 in this thread

http://forums.spiritplants.com/index.php?s=ab580d38f04634d010b644f80ab3cf49&act=ST&f=4&t=2499&st=0

(scroll down to see it and check out the great follow up.) It's reminiscent of other cactus extraction procedures already on the Net, but, this one feels more complete.

This is basically the procedure here:

-----
START WITH DRIED CACTUS -

STEP ONE: EXTRACTION (using methanol)
Grind up cacti to powder put in quart jar until jar is 1/2 full with ground cactus.  Add enough MeOH to fill until about 2" beneath the rim of the jar.  Next Add with 1-3 drops at a time VERY carefull to get the PH up to 1-2.  Continue to check with your pH meter and stir with a wooden spoon or chopstick to evenly distribute the HCL Acid in the solution.  continue to do the same until you fill all the cacti in the quart jars you have. so each look to have the same ratio of cacti to MeOH.  next place the jars in a large pot filled with warm water on the stove so its not simmering but very hot to the touch (up to 100F is fine)  Then shake/swirl gently the contents of each jar periodically over the next 36 hours. 

Next loosely fit a cotton ball into your funnel over a clean quart jar a tiny bit of water so that there is a slow steady drip of about 6-9 drops a second..this will help filter MUCH of the cacti out and leave a dark green MeOH solution containing your the majority of your goodies.  Do this to each jar of MeOH Cacti extract and combine the filtered jars - if you have a distillation kit distill to reclaim the MeOH, if you dont care about the environment pour it in a pyrex baking dish
and let most evaporate until you have about 300 ml dark green MeOH cacti extract concentrate. Filter this concentrated extract through the funnel same as last time store in a jar labeled 'extract #1'. 

Add all cacti material from the last extractions into the jars again with same ratio of MeOH to cacti repeat the steps following that until you have a 2nd MeOH cacti extract pour that into the jar 'extract #1'.  You can repeat the process one last time but you wont get hardly alkaloids you should have about 90% in your jar 'extract #1'.  If you dont want to repeat a 3rd extract toss the spent cacti in a compost and then pour 'extract #1' jar into the pyrex baking dish until i evaps to about 250-300mL.  Filter the 300mL  MeOH contents once more through the cotton funnel (this really cuts down on emulsions).

STEP TWO: DEFATTING (USING METHYLENE CHLORIDE - dichloromethane)
Next add that to the Sep funnel (Make sure the stopper is plugged! you dont wanna lose precious M!  add 60mL DCM, shake vigourously for 10-15 minutes, let settle decant orange DCM at the bottom of the funnel into a glass jar.  Continue to add DCM and decant it until it is a clear color (If you do it this much your crystals will be clear! Combine all DCM removal of fats n lipids and if you dont care about the environment throw it in a concrete street, otherwise distill and reclaim your DCM. 

1st pull - 60mL
2nd pull - 50ml
3rd pull - 40ml
DCM will sink to the bottom because methanol is lighter in weight so decant whats at the bottom of your sep funnel.

STEP THREE: BASIFICATION
Next step is to add NaOH/Lye slowly until a pH of 12 is read on your pH meter.  Remember add small amounts and stir inbetween pH readings for utmost accuracy. 

STEP FOUR: EXTRACTION OF FREE BASES
Now that you have a basified pH 12 Mescaline Freebase MeOH solution add 100 mL DCM, shake 12 minutes, decant and save the DCM that possibly will be a slight yellowish color that just means you'll get yellow xtals.  Repeat DCM extract 3x each time reducing amount of DCM used by 20 mL with each successive DCM pull. 

STEP FIVE: SALT FORMATION AND EXTRACTION
Combine the 3 DCM + Mescaline Freebase solution into a a clean pyrex glass baking dish.  Let it evaporate if you dont care about the environment otherwise distill lazy bitchs!!  Next to the white/yellow gummy fishy smelling phen freebase add 3mL sulfuric acid in 2mL distilled/purified water. Watch as streaks of needles appear after drops are added to the goo.Yes make a solution of 3mL H2SO4 and 2mL dH2O - drip this slowly with a pipette onto your fishy smelling mescaline freebase.
Get a PH Meter, it will be a salt from pH 2-3 that is fairly acidic.  Purchase 31% Muriatic Acid for cleaning pavement at Home Depot.  Slowly add 1-2 drops at a time via pipette of this HCL into your Cacti MeoH solution checking pH frequently until it reachs 1-3.  This makes the alkaloids hcl salts.  Do _NOT_ use Vinegar for this process.

STEP SIX: EVAPORATION
Let dry scrap n recrystallize with boiling IPA for nice pure clear xtals.
-----

Our Shaman is currently finishing up STEP TWO after having removed all the MeOH, replacing it with NaCl saturated dH20 - probably too much salt. This yielded 355 ml of golden honey brown liquid which is defatting in DCM for the third, and possibly final, time - the DCM is clear.

Thanks for your positive feed back.