I’m confused about the connection of THCa salts and butane extraction.
Are you thinking that the salt form of THCa is more non polar and can be extracted more effectively?
My thinking is that if the salt form is present in any significant amount and if the salt form has significantly different properties (more non polar) than THCa, we would see a separate peak during testing.
A prior ? What form is it in when it is in the storage lumen of the trichome.
Why would you even think it is COOH form?
The storage lumen would have to have an effective pH of about 2 to
have a 10:1 ratio COOH over COO- in situ?
So the question is how does butane even work? Considering the plant
physiological pH is about 6.5. Ion pairs are neutral, ionic charges are diminshed by ion pairing ,or sheilded by detergent micelles (in this case terps) and can be
extracted into non-polar.
When you inject onto an HPLC column…the solute will experience the effective pH of
the Solvent you are pumping…in the case of RP C18 it is usually formic acid?
Change your buffer to pH 8.0 and you will see an entirely different peak position.
And that is why you see 99% HPLC done with Methanol, water and Formic Acid.
You won’t see two peaks and you are missing the point.
If you acidify your carboxylic acid is H+ -00C-R…it is neutral…and it can be extracted into
butane.
It is highly unlikely due to pH conditions of plant material that this is the form of the
Carboxylic acid is in…Your plant material is NOT pH=2.*
Butane works but it is unexplainable. Some mechanism has to shield the carboxylic
anion in butane.
How do you prepare the pentane/heptane THCA solution? Do you use any CRC?
CRC complicates the issue considerably.
Wash it with 5% HCl in ddH20 …and see what you get when you do the experiment.
Wash it with Sodium Acetate in ddH20, see what you get.
Did you measure the pH of the distilled water wash? curious.
The solubilty question is not pertinent to EtOH extraction (alcohols).
Were you ever trained with weak acids and bases, buffers?
Finally I think I understand your point
THCa in the plant is stored at pH 6.5 (if it’s stored at the same pH as the plant exists in general, which we wouldn’t have any reason to expect)
THCa carboxylic acid should be deprotonated in that situation and therefore difficult to extract, but it isn’t
My answer would be that if THCa is accumulating next to mainly other THCa molecules in a globule, you aren’t going to see the deprotonation work the same way as theoretical chemistry says it would in solution
If the THCa were evenly distributed throughout the cells of the plant in some sort of watery vacuole at high pH we might have to worry about it but even then.
Yes, indeed on all points except the very last .
It is clear that theoretical dilute solution aqueous is NOT at play
because of the fact that butane works. yes…
The synthase is excreted into the extracellular space. Work with purified synthase
suggests it likes an environment pH 5.0 and Tween. I don’t have any other info about
the environment of the lumen, The concentration of terpenes,or the amount of water and or ionic conditions, It might even be multiphasic. ??
I have suggested numerous solutions to the butane extraction phenomena:
ion pair solution, carboxylic acid dimers, intramolecular hydrogen bonding and detergent
action of hydroxylated terpenes.
If the THCA H+ form predominates, the [H+] has to come from somewhere?
Presumably, the THCA leaves the enzyme in the COO- form. ??? The deprotonation
(disassociation) concept is basically a dilute solution concept. Remember, it is highly
likely the THCA is participating as a weak acid buffer as well. Altered disassociation
process is not the only answer. (above).
Edit:
I think ion pairing with inorganic cations such as Na+ is unlikely,
so let us scratch that.
To be honest, I do not know.
You guys are saying there’s no reason theoretically why butane should be able to dissolve THCa?
Aren’t trichomes encased in a protective phospholipid? Couldn’t it just be something as simple as the thca is already dissolved in terpenes and can disperse in the butane easily with the phospholipid layer dissolved?
But we can dissolve thc-a isolate in butane though right?
*warm butane (above boiling point)
I dont see anything online at the moment that suggests the carboxylic acid would be deprotonated leaving thca synthase. Assuming it’s neutral at that point I think it’s safe from ionization in the extracellular space
anything you read on line, or in the scientific literature especially, is going
to assume you understand the weak acid equilibrium is controlled by the pH.
They are not going to say: “the substrate is loaded as the non-ionized” : they just note the pH of the reaction. Perhaps if they did crystallography of the enzyme with the substrate loaded they would be able to tell what form was loaded.
I understand your point…“.extractable” is not evidence of being “safe from ionization.”
My assumption is base on the enzyme rxn conditions as pH 5.0 in vitro.
I noted above this does not necessarily have to be the actual pH of the lumen
especially if the plant has H+ “pump” system to acidify the lumen. Plenty of enzymes are very active at low pH. I’ll write those guys and ask is anyone did a complete pH profile
of reaction rates.
Just as the flowering begins the terpene profile changes to predominate monoterpenes.
Let us assume this new mixture of terpenes acts as a detergent or solvent to solubilize the
the cannabinoic Acids in the storage space. For a better term lets call it “Terp-Acid complex”
and it is this complex that results in the solubility of the THCA in butane, irregardless of the
ionization state.
If we did a -40C n-hexane extract of biomass and then dried it at less than 30C and pulled a very high vacuum to remove the lighter terpenes as well,
Is the resulting material soluble in hexane at -40 C?
If it is not…it is the terps. or a Terp-Acid complex.
Why do people have to heat their solvent to readily resolvate THCA after purification,
when it should happen easily at -40C? (surface area aside)
Assuming the Carboxylic Acid is protonated in the storage space is clearly
one possible answer.
If you look here , the researchers who did the work characterizing the
enzyme and sustrate action: * DOI: 10.1016/j.jmb.2012.06.030
the diagram that accompanies figure 4 and the legend below
Clearly shows that they assume the CBGA loaded as substrate and the THCA
released as product are in the ionized form: COO- (minus)
Fig. 4. Proposed catalytic mechanism of THCA synthesis from CBGA, based on the mutational analysis and the crystal structure of THCA synthase.
I really don’t get this ‘mystery of extraction’ bit. This whole net positive interaction between solvent and solute doesn’t happen in organic chemistry.
There is never a net positive attraction between organics. You’ll have transient van der waals forces, but most of what you have is organics just being less repulsed by other organics than by a polar compound.
I’ve always assumed that the nonpolar solvent dissolves the trichome and just washes its contents out.
Super interesting. I don’t know! The hydrogen peroxide formed in an earlier step is not going to help the situation.
According to this paper the CBGa would be ideally deprotonated to even interact with the THCa-S. So we need a mechanism for re-protonation OR a mechanism for butane to extract the deprotonated stuff
You are right that people usually assume that we know about the state of the pH and I think that’s part of why no one has even brought up this question. Not a fault of anyone on this site, I can’t find any papers that know the answer to this. Very cool find there’s definitely some good questions
Yes…solution chemsitry for organics is mostly van der waals
and other induced “dispersion” interactions.
Nonpolar solvents “wash out” all that is miscible.
We are talking about the immiscible aspects of THCA.
There are aqueous solutuons, organic miscibilty and
detergent micelles- “solutions” representing neither organic
or aqueous.
I assume you have studied separation chemisty in the formal sense, and how one exploits the subtle differences in organic “solution chemisty and physics”
to effect separation, RP C18 separations being a good example.
Thank you for the most interesting demonstration
of interface precipitation and crystal growth!
Also thanks for your curiosity allowing me to interject
this academic “non sense.”
We all know Butane works!
I’m thinking the same question applies to CO2 extraction. Maybe some of the older players like Waters have thought about this
https://www.instagram.com/p/BfZcgqQnGRA/?utm_source=ig_web_copy_link
Back in early 2018, I played around with this with ethanol extracted crude after a few scrubs in pentane.
Wow that is a rock! Maybe tall and skinny is the way to go
Thanks for the share, So you reduce the etoh and then do the LLE to switch into pentane, then add water and form the 2 layers …
Or add the water to the etoh and then pentane and form the 2 layers?
I am in love of this Tread
Yeaaaaaaa
Using a container with a high aspect ratio to crystallize in will always give you better results.
The first one, with a few water washes to remover residual ethanol and water solubles. You can also run it through a column with your adsorbent of choice then, reducing the pentane before adding water again. I would suspect that would increase your yield.
