• Bluelight HOT THREADS
  • Let's Welcome Our NEW MEMBERS!

A quick summary of trichromes and the biosynthesis of THC

psychedelicious

Bluelighter
Joined
Nov 19, 2005
Messages
993
Location
lone star state
A quick summary: Trichromes, biosynthesis of THC, & Indica vs Sativa

There seems to be an ungodly amount of confusion over THC, its physical location in the cannabis plant, and the purpose of it / trichromes. I hope this post will help out those not in the know to figure out what's going on with THC and trichs.

Trichromes and Cannabinoid Production

Trichromes are glandular hairs which are found on many different plants. We lucked the fuck out with bud - its trichromes are quite a bit of fun! 8o

Trichromes serve two main purposes:
1) They are sticky and aid in catching male pollen. More trichromes = better chance of pollination.
2) THC absorbs UV-B light very well, acting as a veggie sunscreen. THC is produced in the trichromes.

(It is thought that the trichromes and cystolith hairs, which we will get to in a minute, on herb might also play a role in deterring animals from eating the plants by making them less palatable, however, anecdotal evidence suggests that many animals find bud to be DELICIOUS. Humans are included in "many animals". =D)

2ndtrichay4.jpg


This macro shot shows the different types of trichromes as well as tiny hairs (called cystolithic hairs - "hairs" whose cells contain mostly calcium carbonate).

The red arrow points to a cystolithic hair. Note: cystolithic hairs are not the little red hairs we all know and love. Those red ones are way bigger than cystolithic hairs, which, in cannabis, at least, are unicellular.

The yellow arrows point to bulbous glands, which are very, very small (2 to 8 cells big), and contain minimal amounts of cannabinoids. They are one of three types of glands.

The blue arrows point to capitate-sessile glands, which eventually mature into the third and last type of gland: capitate-stalked, which are indicated by the green arrows.

img0446gn8.jpg


In this photo, you can see the tops of capitate-stalked glands, and perhaps some capitate-sessile glands. The bulbous glands are too small and too blurred-out to see in this photo.

Capitate-stalked glands are what most people refer to as trichromes. At the bottom of these glands are various phenols and turpenes, which are precursors to cannabinoids. The "head" of the capitate-stalked gland contains the cannabinoids. Gland age and THC content are directly related (older = more THC). As the phenols and turpenes are moved up the stalk and into the "head", they are progressively biosynthesized into cannabinoids: first to CBG, then CBG > CBC AND CBG > CBD, and finally, CBD > THC. CBN, the compound which THC primarily degrades to, forms only after the plant has died. The image below shows the biosynthesis progression.

moleculezw9.gif

1 = CBG (cannabigerol)
2 = CBD (cannabidiol)
3 = CBC (cannabichromene)
4 = THC (delta-9-tetrahydrocannabinol)

These glands grow up to half a millimeter tall. They are the ones you want, and they grow all over the aerial parts of the plant (anything above ground).

Here's a good read from the UN's Office on Drugs and Crime: LINK
And the wikipedia article on trichromes: LINK

Indica vs Sativa and Different Highs

So why do different pots have different effects? It has to do with the ratio of CBD and THC at the time of harvest. Most of the effects of herb are attributed to THC. When CBD (which has little to no effect on its own) is taken in conjunction with THC, it adds sedating and euphoric qualities to the high.

The time it takes a sativa plant to reach maturity is quite a bit longer than the time indica requires (once flowering has begun, 10-16 weeks for sativa compared to 6-8 weeks for indica). This makes all the difference in the high! Scroll back up to the graphic depicting the progression of cannabiniods. The longer a plant is alive, the longer its resin glands have time to take the steps to get from CBG > CBD > THC. Thus, as time goes on, the ratio of THC to CBD increases (meaning more THC and less CBD). This also means that plants that reach maturity faster have a lower ratio of THC to CBD (meaning less THC and more CBD).

Putting it all together...
Since sativas take quite a bit longer to reach maturity, they have more time to build up THC and have less CBD. This gives sativas a cerebral, psychedelic, and stimulating high - trippy buds.

Indicas, on the other hand, reach maturity much sooner than sativas, and so have less time to build up THC and have more CBD, giving indicas an extra bit of euphoria and sedation - couchlock buds.

For example, a sativa plant might have a THC:CBD ratio of 3:1, while an indica plant might have a THC:CBD ratio of 1:2.

Ah, and then there is ruderalis, which, it appears, has high levels of CBD, but no THC (or at least very, very little - not enough to get you high at all). Somebody with access to ruderalis ought to do a butane extraction and mix in some of the resultant oil with a bowl of straight sativa to see if the high is sedating instead of stimulating.

Another cannabinoid which is found primarily in Indian, Nepalese, S. African, and Afghani indicas is tetrahydrocannabivarin (THCV). THCV actually antagonizes (reduces, in this particular case) the effects of THC. This could possibly increase the sedating and euphoric effects of indica pots from these parts of the world, which are the varieties from which hashish is traditionally made.


Hope that clears a few things up!

<3
 
Last edited:

TheRiseIsTheFall

Ex-Bluelighter
Joined
Jan 4, 2008
Messages
1,348
good post.

Fyi all you growers for that wonderful medicinal high on most indicas it's wise to wait until the trichomes turn a amber colour(couchlock anyone?)


Mmmmmmmm, Looking at this pic makes me hungry.
 

keithwired

Bluelighter
Joined
Nov 27, 2007
Messages
26
yes amber colored trichomes means a higher CBN concentration whereas whiter or clearer trichomes means higher THC concentration = sativa cerebral head high
 

theWorldWithin

Bluelighter
Joined
Oct 22, 2005
Messages
1,299
psychedelicious said:
As the phenols and turpenes are moved up the stalk and into the "head", they are progressively biosynthesized into cannabinoids: first to CBC, then to CBG, then to CBD, and finally to THC. CBN forms only after the plant has died.

THen why do growers harvest plants early for a more cerebral sativa type high? I have heard before that this synthesis occurs in the above order so maybe its a fairly quick process. Does THC degrade back to CBD in vivo while the plant is still alive? If not then why do plants in the earlier stages of maturity have a higher THC to CBD ration (while trichomes are still clear)?

By the way, nice to see some intelligent discussion in this forum for a change!
 

psychedelicious

Bluelighter
Joined
Nov 19, 2005
Messages
993
Location
lone star state
keithwired, I believe you mean CBD, not CBN?

theWorldWithin, that's a good question. AFAIK, THC does not degrade back into CBD, though, once the plant has died, THC does degrade into CBN. I'm not sure about plants in the earlier stages having a greater THC:CBD ratios...

Perhaps at the start of growth, the plant rushes to make THC to block the new leaves and growth from the sun, until the plant gets a bit larger and can deal with the heat better. Then, during the middle stages, it slows this process down, and the ratio decreases, until the end when it speeds up to protect the buds from sunlight? Let's figure this out.

btw, I added an indica vs sativa section and an image showing the cannabinoid progression.
 

MyDoorsAreOpen

Bluelight Crew
Joined
Aug 20, 2003
Messages
8,550
TheRiseIsTheFall said:
Mmmmmmmm, Looking at this pic makes me hungry.

Yeah that's about my first and only thought. I read this post like I read the articles in Playboy.
 

double ewe

Bluelighter
Joined
Mar 13, 2008
Messages
2,145
Thanks for posting! I find myself bringing up this thread on peoples' computers about every time I smoke these days.
 

Slay

Ex-Bluelighter
Joined
Dec 21, 2003
Messages
7,934
Location
ı-¦===l>--
awesome thread psychedelicious thank you:) i would love to read more about cannabinoids. also it would be nice to read some cannabinoid biotrasformation:)
 

Czar420

Bluelighter
Joined
Apr 4, 2007
Messages
200
psychedelicious said:
Perhaps at the start of growth, the plant rushes to make THC to block the new leaves and growth from the sun, until the plant gets a bit larger and can deal with the heat better.
So does that mean one could germinate and sprout a few hundred baby plants and whack them down while they are young for the "nutrients". Much like how people eat baby spinach?
 

time traveler

Bluelighter
Joined
Jan 23, 2005
Messages
666
Top stuff psychedelicious !

Funny how some people i know still think they are smoking the leaf.

At the other end now i can trump wikipedia drug nerds with a single treatise on THC biosynthesis.

Cheers :)
 

psychedelicious

Bluelighter
Joined
Nov 19, 2005
Messages
993
Location
lone star state
neverstop said:
duh. thanks :)
Czar420 said:
So does that mean one could germinate and sprout a few hundred baby plants and whack them down while they are young for the "nutrients". Much like how people eat baby spinach?
I would be willing to bet that baby pots are more nutritious than mature pots.
time traveler said:
Top stuff psychedelicious !

Funny how some people i know still think they are smoking the leaf.

At the other end now i can trump wikipedia drug nerds with a single treatise on THC biosynthesis.

Cheers :)
centro said:
great post dude

Riddle said:
Pornographic and informative, good post :)

muchas gracias!
 

BuddyBoy

Greenlighter
Joined
Nov 2, 2008
Messages
1
hey i hopped over from Planet ganja, GREAT article! much appreciated. BUT I disagree on a fact posted here. You claim that the blue arrowed glands "grow" into the green arrowed glands? Like a mushroom? And the red arrowed gland is another type of gland?

In my opinion(15yr Harvester) thats a photo of an "early" ripe section of a calyx. All my experience under the scope shows glands like the red arrowed glands early in maturity and their tips form the heads as they swell and mature and eventually form the green arrowed structures. The stalks of these glands grow in gerth as well during the ripening process.
This observation is reinforced by the fact that there arent ever any "short" glands "growing into stalks.
I have seen small balls on the ends of glands though.

A stop frame reference of one particular section of a ripening bud would be of great help here but a complete pain to film.
 
Top