Questions on Chemical Properties of THCa, etc.

[thetripscaptain]

Hello everyone, holy crap it's been 8 years since I posted here last. I am stopping by because I'm looking for some information about the chemical properties of Tetrahydrocannabinolic acid (2-COOH-THC). This is the molecule synthesized by the Cannabis plant which will become THC (decarboxylate) when heated during smoking/vaping or baking. I will refer to it as "THCa" from here on.

Before I start let me state I did search for this information through archives, etc. and while I found some information which was close to helpful, the threads generally changed gears quickly into discussion of making "snortable hash" 8) or discussion of synthetic cannabinoids which are water soluble. This is not the information I'm looking for, although some of the synthetic cannabinoid alkaloids are interesting.

The first thing I wonder is, can THCa readily form salts? I have limited understanding of chemistry but my understanding is that THC cannot form salts because it doesn't have any structures in the molecule that grant it acidic or basic properties; therefore it cannot be neutralized with an acid or base to form a salt. So I am curious if the THCa can form salts due to the carboxylic acid group, or is there an additional problem (lack of nitrogen in the molecule for example) that prevents it from forming salts. To be clear I'm not talking about a salt which is specifically water soluble, suitable for any specific route of administration, or is even fit for consumption by humans in any way. (Also I think it's non-psychoactive anyways.) I am purely asking if it has the chemical properties necessary to readily form salts when neutralized with a base. Also what physical properties might the salts have?

I have the same questions about the Cannabidiolic acid (acid form of CBD) as well, but I would expect these compounds to have similar physical properties.

The next thing I wonder is related to the fact that when I see test results of BHO / wax / shatter / bubble hash / etc, the main cannabinoid content of the material is the acid forms of the molecules. A rough average of the last few specimens of this type that I've seen is something like 70-90% THCa and 1-3% THC. These materials are generally extracted using butane or similar solvents but in some cases ethanol is used and in the case of bubble hash only water and agitation are used to collect trichomes.

So having explained that, I recently saw test results from a material extracted using CO2:

82.78% total cannabinoids
THCa <0.001%
THC 76.24%
CBDa <0.0025%
CBD 0.61%
CBN 0.85%
CBC 2.09%
CBG 2.60%

Note in this material the THCa and what little CBDa was present have been pretty thoroughly decarboxylated. So I am assuming one of two things happened: First, perhaps the makers of the material simply heated it to intentionally decarboxylate the THCa/CBDa, making it suitable for oral consumption. Second, could the CO2 have decarboxylated these molecules during extraction? I'm not sure if that makes any chemical sense or not but I was curious if somehow the CO2 itself decarboxylates the THCa/CBDa. I'm just wondering if the cannabinoid profile shown here is the result of the CO2 extraction or if it's the result of further processing using heat and the CO2 played no role whatsoever.

Also this material has no Cannabis-like smell to speak of. None of the aromas of Cannabis flowers are present whatsoever and the taste is purely bitter. This leads me to assume that the scented terpenes present in Cannabis flowers (D-limonene, etc.) are not present in any significant quantity at all and I again am wondering if this is due to them being destroyed by heat or by the CO2 perhaps not extracting them well.

Thanks for reading and thank you all in advance for any info provided.

Peace - Trips

 

[sekio]

THC acids can form salts, but they would behave like soaps and would have low water solubility.

Properly cured marijuana will decarboxylate on its own, so will any extract that is processed with heat or acids.

 

[w01fg4ng]

Properly cured marijuana will decarboxylate on its own

Curing is not a process which aids a decarboxylate. All curing does is aid in keeping the bud from drying out (which makes it taste better...bottom line).

In fact, I would bet professional grow ops made for CO2 extractions completely skip the curing process all together. If I remember correctly from a speech given yesterday at the Cannabis Cup, CO2 extraction involves completely drying out the bud prior to extracting it. This is one of the problems facing it's popularity: IT HAS NOT SMELL. This is because the terpenes are lost the more the plant dries. Sense Co2 requires complete dryness for proper extraction, a cure would be completely unnecessary.

I would also bet the process for all of this could aid in the decarbing process, but yes CO2 extractions should naturally have more decarbing done to them because the buds need to be BONE DRY.

 

[Felonious Monk]

Curing is not a process which aids a decarboxylate. All curing does is aid in keeping the bud from drying out (which makes it taste better...bottom line).

In fact, I would bet professional grow ops made for CO2 extractions completely skip the curing process all together. If I remember correctly from a speech given yesterday at the Cannabis Cup, CO2 extraction involves completely drying out the bud prior to extracting it. This is one of the problems facing it's popularity: IT HAS NOT SMELL. This is because the terpenes are lost the more the plant dries. Sense Co2 requires complete dryness for proper extraction, a cure would be completely unnecessary.

I would also bet the process for all of this could aid in the decarbing process, but yes CO2 extractions should naturally have more decarbing done to them because the buds need to be BONE DRY.

I'm not sure that's actually true. I know people that run CO2 machines and the material doesn't have to be any drier than it does for anything else, just dry enough to not mold while it's waiting to be extracted. You're correct however that they don't cure the material the same was as material to be sold for smoke, there's no point since CO2 extraction strips the terpenes off anyway.

Curing will decarb a little, but it would take years to fully decarb with time, before which the bud would dry and unpleasant to smoke. The normal way to decarb is through heating.

As far as concentrates, BHO is THCa, CO2 can be either (more often THCa though), ethanol-extracted/RSO is THC (always decarbed), bubble hash is THCa.
[obviously any of the THCa ones can be heated to decarb, but only RSO is decarbed in the extraction process].


To answer the OP's Qs:
1. As this is CO2 oil, it was decarbed with heat post-processing.
2. It has no smell because CO2 extraction removes all terpenoid content. (There are CO2 products with re-introduced terpenes however, like Clear Concentrates.)

 

[w01fg4ng]

^ There isn't a rule that "BHO is THCa", because the process is what decides how much is decarbed.

I understand that when doing CO2 extractions, pulling any and all water concentration is a very big concern (have you never had poorly made CO2?). Why would your friends make their job harder by leaving water in the plant prior to extraction...I have no idea.

I've made both decarbed and non-decarbed ethanol-extracted as well as isopopyl-extracted THC and I have seen both decarbed and non-decarbed BHO. There isn't a "rule" for these kinds of things.

 

[Felonious Monk]

It's true there's not a rule, but there is chemistry. The process determines the outcome.

When you make BHO, if it's made correctly, the final product should be majority-THCa. That is a fact. This is the only way to preserve the terpenes (in the BHO process that is, and even when compared to other extraction processes it is the most efficient, except for maybe Propane, but that's up for debate).

You can then decarb that BHO with heat. You've now done post-processing.

I'm curious what ethanol-extracted oil was not decarbed? My understanding is that the temperatures required to remove the alcohol will decarb the oil.

 

[Doldrugs]

Properly cured marijuana will decarboxylate on its own

Maybe over a period of years. If you're going to use marijuana without heat, you need to decarb it first. The idea that cured weed you buy is mostly decarbed is completely absurd.

I'm curious what ethanol-extracted oil was not decarbed? My understanding is that the temperatures required to remove the alcohol will decarb the oil.

Ethanol evaporates quickly and easily at room temperature. Throw a fan on and you'll have no-heat concentrate in a few hours.

 

[Felonious Monk]

Ethanol evaporates quickly and easily at room temperature. Throw a fan on and you'll have no-heat concentrate in a few hours.

Fair enough. That'd be a very small run though (like QWISO, I'm assuming what wolfgang was referring to as well).

I'm not actually sure what the difference is between QWISO (or using ethanol), and RSO. Maybe just the time of the wash? I know some people only wash their RSO for a few minutes as well, but it's oil not hash.. Or maybe it's the size of the run? A quick small run will produce hash (because it doesn't need heat to evap), vs a larger run will make oil (I'm used to people extracting from a lb at a time)

 

[w01fg4ng]

^Yeah it was a small op and dried up using a fan like Doldrugs said. However I have made shatter-like quality with QWISO using a natural dry method (with no fan). I still have some sticking to a plate (probably 4-5 years old) that is insanely TOO stable for my liking.

When you make BHO, if it's made correctly, the final product should be majority-THCa. That is a fact. This is the only way to preserve the terpenes (in the BHO process that is, and even when compared to other extraction processes it is the most efficient, except for maybe Propane, but that's up for debate).

I would imagine that most extractions would prefer to preserve the terpenes, but I'd imagine the lack of terpenes in the CO2 brings opportunity for making some killer edibles too

 

[Felonious Monk]

I would imagine that most extractions would prefer to preserve the terpenes, but I'd imagine the lack of terpenes in the CO2 brings opportunity for making some killer edibles too

That's my experience. I like BHO for dabbing because I can variety of taste. CO2 can make great edibles or certain liquid medicines, but I don't really like smoking it or eating it on its own. I have been enjoying some CO2 with reintroduced terpenes though, an interesting avenue to make pharma-grade meds (CO2 extracted), but still have incredible synergistic properties (with custom terpene blends for desired effects).

 

[bigfondue]

THC acids can form salts, but they would behave like soaps and would have low water solubility.

Properly cured marijuana will decarboxylate on its own, so will any extract that is processed with heat or acids.

If THC salts would behave like soaps(emulsifying), wouldn't that increase its solubility, and the solubility of anything non-polar. Isn't that what a soap does be definition? I'm confused, I feel like I'm missing something.

 

[w01fg4ng]

That's my experience. I like BHO for dabbing because I can variety of taste. CO2 can make great edibles or certain liquid medicines, but I don't really like smoking it or eating it on its own. I have been enjoying some CO2 with reintroduced terpenes though, an interesting avenue to make pharma-grade meds (CO2 extracted), but still have incredible synergistic properties (with custom terpene blends for desired effects).

That sounds really cool. I wonder at what point is "too much" terpenes. Like, at what point does it start tasting like metal from too much Myrcene...or would the Limonene override the Myrcene's taste...or maybe it depends on the strain it's extracted from, etc. Off topic and this is probably very controversial but I wonder how different you can make cannabis extracts taste by introducing terpenes from another plant, like a fruit?

 

[Felonious Monk]

That sounds really cool. I wonder at what point is "too much" terpenes. Like, at what point does it start tasting like metal from too much Myrcene...or would the Limonene override the Myrcene's taste...or maybe it depends on the strain it's extracted from, etc. Off topic and this is probably very controversial but I wonder how different you can make cannabis extracts taste by introducing terpenes from another plant, like a fruit?

Well it's WAY less terpenes than you would think. I was hanging out with an extractor the other day and he told me it took only 1 big stinky nug to extract terpenes to flavor a whole pound's worth of oil (60-80g).

As far as strain, it does depend, but people often add the terpenes in from another strain. Like, they use either high grade trim or low grade flower to extract the THC, then they use a heady piece of flower to get the terpenes.

I have heard of people using non-cannabis terpenes but that is controversial within the community because of concerns over where the terpenes came from and if they're safe to consume. I've also heard complaints that you shouldn't pollute cannabis like that--better to use terpenes extracted from cannabis.

I've seen an incredible variety of flavors though, everything from the ones you'd expect (oranges, lemons, bubblegum), I've seen some pretty out there flavors, like Strawberry Cheesecake.

 

[w01fg4ng]

I would think it would be more of a novelty to introduce terpenes extracted from other plants (imo it just doesn't seem worth it to go through all that work), but take a look at what the the tobacco industry did to most commercial cigarettes; there's tons of added crap for "flavor".

Maybe someday commercial cannabis oil will be so popular that we will have to have brands that claim to be "All Natural 100% Cannabis", because so much oil will be injected with crap from other plants.

Lol just a thought.

 

[thetripscaptain]

The idea that cured weed you buy is mostly decarbed is completely absurd.

This is what I would have thought as well. I'm sure a little bit of the acids will decarb but I have been logging test results of samples I've received for a few weeks now and in whole cannabis the THC/CBD is nearly always in the acid forms, with decarbed THC often accounting for less than 1% of the weight of the cannabis.

I'm curious what ethanol-extracted oil was not decarbed?

Let me clarify why I mentioned ethanol. I have a sample which lists the solvents as "ingredients" on the packaging along with hash, and the list is as follows: Sirline (sic), Butane, Propane, Ethanol, Hash. I assume what they are doing is listing every solvent that they might have possibly used, not saying that all of those solvents are used together to extract the same product, but it does list ethanol so I mentioned it in the 1st post. The material I had was wax and I doubt ethanol was used in the extraction of this specific material but honestly I'm not sure as I'm not terribly experienced with ethanol extracts of cannabis.

(Also, wtf is Sirline? I wondered if maybe it was just a brand name of butane gas or something but do a Google search for sirline and you find nothing relevant.)

On the subject of adding other terpenes to weed extracts that sounds interesting if only as a novelty kind of product. I'd imagine if you wanted to introduce say, D-limonene into a CO2 oil, lemon oil would yield a ton more of it than cannabis would, and this may prove more cost-effective for commercial production of such a product. Although if the amount of terpenes required is indeed so minuscule as described above, it may not be cost-prohibitive in the first place to simply use terpenes sourced from cannabis.

I have a friend who, when he would get some weed that maybe smelled grassy or like it was cut premature or improperly cured, would take a small piece of lemon or orange peel and make tiny slits into the zest (outermost layer of citrus peel) in order to squeeze tiny squirts of lemon/orange oil onto his buds. Keep in mind this is the oil from the zest, not the fruit juice itself. Actually it was quite tasty when applied properly, i.e. not too much.

Peace - Trips

 

[Doldrugs]

This is what I would have thought as well. I'm sure a little bit of the acids will decarb but I have been logging test results of samples I've received for a few weeks now and in whole cannabis the THC/CBD is nearly always in the acid forms, with decarbed THC often accounting for less than 1% of the weight of the cannabis.

For some reason there's virulent opposition to the concept of decarboxylation among many cannabis users. I don't understand why they're so militant about it when the science is very clear and it can save you quite a bit of money on dud edibles. Maybe it's stereotypical stoner laziness? It's frankly baffling to me.

 

[thetripscaptain]

For some reason there's virulent opposition to the concept of decarboxylation among many cannabis users. I don't understand why they're so militant about it when the science is very clear and it can save you quite a bit of money on dud edibles. Maybe it's stereotypical stoner laziness? It's frankly baffling to me.

To be honest I only recently learned this information myself, after coming to an area where detailed test results are the norm. Actually it answered some questions I'd always had about edibles and orally ingested cannabis which I could never quite answer with certainty. I'm not sure how long this information has been available but I'd bet a lot of folks simply haven't got the memo. Now if someone has been told about decarbing and why it's required, and they're still against it, then idk what the mentality behind that would be. Like you mentioned edibles could be duds if the THCa is not decarbed. Correct me if Im wrong, but THCa is entirely non-psychoactive, right?

Peace - Trips

 

[Artificial Emotion]

Freshly harvested weed contains a large amount of THC in the form of THC acid (THCA). This is not psychoactive but when the plant material dries and ages it converts the THCA to THC through naturally occurring decarboxylation. Most THCA converts to THC in up to 2 years but by this point most of the THC will have converted to CBN anyway. Heating is used to speed up decarboxylation either through smoking or gentle cooking with edibles.

Check out this graph: the graph of the effect of heating time and temperature on the THC content of n-hexane marijuana extract after heating on the glass surface in an open reactor:

To decarb your plant material place bud or trip on a baking tray spread out and place into an oven set at 223F (106°C). After 25 mins use in your recipe.

Just to be clear and to reiterate though, decarboxylation will occur when curing.

 

[Doldrugs]

Now if someone has been told about decarbing and why it's required, and they're still against it, then idk what the mentality behind that would be. Like you mentioned edibles could be duds if the THCa is not decarbed. Correct me if Im wrong, but THCa is entirely non-psychoactive, right?

There's numerous posters on this site and on every other site that hosts cannabis discussion who feel quite strongly that decarbing is unnecessary or pointless and will argue it despite being provided contrary evidence. It's never made any sense to me. The information is out there and it's readily available. I don't know why people continue to waste weed and money when they could be using smaller amounts to make 100% reliable edibles. How many times have you heard someone say "edibles are unpredictable, require way more weed than smoking, and don't do anything half the time"? If you're not decarbing, that's what you can expect.

 

[tacodude]

There's a book called cannabis alchemy or something that talks about producing thc-acetate with glacial acetic anhydride or something whatever is used to convert morphine to heroin i believe. It's a strong reaction that one should not attempt without lab experience and the knowledge to understand what one is doing.

There is only one person I can think of who made it successfully on the regular and still there aren't many stories of its use. It is supposedly a stable edible, sortable, and injectable Form of thc. Completely unnatural and knowing what heroin became after morphine who knows what bad tenancies thc-acetate can bring out. Than again it would be cool to see.

Edit : I can see propane and butane being used together while ethanol is used to clean the waxs out of the end product. The other ingredient I have no clue what it is.