Chemometric Analysis of Cannabinoids: Chemotaxonomy and Domestication Syndrome

[Elvin]

Abstract
Cannabis is an interesting domesticated crop with a long history of cultivation and use. Strains have been selected through informal breeding programs with undisclosed parentage and criteria. The term “strain” refers to minor morphological differences and grower branding rather than distinct cultivated varieties. We hypothesized that strains sold by different licensed producers are chemotaxonomically indistinguishable and that the commercial practice of identifying strains by the ratio of total THC and CBD is insufficient to account for the reported human health outcomes. We used targeted metabolomics to analyze 11 known cannabinoids and an untargeted metabolomics approach to identify 21 unknown cannabinoids. Five clusters of chemotaxonomically indistinguishable strains were identified from the 33 commercial products. Only 3 of the clusters produce CBDA in significant quantities while the other 2 clusters redirect metabolic resources toward the THCA production pathways. Six unknown metabolites were unique to CBD-rich strains and/or correlated to CBDA and 3 unknowns were found only in THC-rich strains. Together, these data indicate the domestication of the cannabis germplasm has resulted in a loss of the CBDA pathway in some strains and reallocation of resources between CBDA and THCA pathways in others. The impact of domestication is a lack of chemical diversity and loss of biodiversity in modern cannabis strains.
Chemometric Analysis of Cannabinoids: Chemotaxonomy and Domestication Syndrome
(published 30 August 2018 at "Scientific Reports" a natureresearch journal)

 

[Elvin]

First two paragraphs of the introduction:

Cannabis sativa L. (marijuana) is a dioecious, annual plant from Central Asia that has been used medicinally and recreationally for thousands of years1. The domestication of cannabis has included human selection, inbreeding and cross breeding as well as natural outcrossing and genome mixing1. Strains are not easily delineated by genotype and only moderate correlations have been observed between C. indica and C. sativa ancestry. In addition, large genetic variance has been observed within identically named strains2,3. Standardized, highly controlled programs to breed elite varieties or cultivars by selection of phytochemical profile have been limited4,5. It is estimated that there are several hundred or perhaps thousands of strains of cannabis currently being cultivated in legal and illegal markets4. It is possible that chemically identical or very closely related plant material is being sold under several different names by different producers and there is no clear definition of the concept of a “strain”.
Cannabis producers market their products based on the amounts of total Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) with the assumption that the overall phytochemical composition of the material can be extrapolated from these values, but there is considerable anecdotal evidence suggesting that strains with similar THC/CBD content have different effects on human physiology6,7. More than 120 different cannabinoids have been described in cannabis8,9 with the most interesting phytochemistry found in the glandular trichomes on the flowers of the female inflorescences10. THC is the most researched cannabinoid and there are ten additional classes of cannabinoids with varying chemical structures8. Cannabinoids are synthesized in acidic forms through the condensation of geranyl diphosphate (GPP) and most commonly olivetolic acid, products of the methylerythritol phosphate (MEP) and polyketide pathways11,12. There are several other polyketides that can be used in place of olivetolic acid, which contribute to the wide variation within this chemical class13,14. Neutral cannabinoids are products of decarboxylation from processing and handling harvested flowers. Chemometric Analysis of Cannabinoids: Chemotaxonomy and Domestication Syndrome

 

[Dusted]

I read a similar abstract recently. Interesting stuff.

 

[Papageno]

I am wondering if there is any new info here. Looks like from above this is a mostly just combining other peoples stuff and republishing. Is there anything to be learned reading this article? Did they do any research here or just write down their thoughts?

 

[TheFertilizer]

I am wondering if there is any new info here. Looks like from above this is a mostly just combining other peoples stuff and republishing. Is there anything to be learned reading this article? Did they do any research here or just write down their thoughts?

It was kind of interesting, they did do some of their own statistical analysis. They were sampling genetic markers that indicate THCA-synthase or CBDA-synthase pathways, and then basically compared the stats of prevalence between each in the samples tested. It basically revealed what we already knew/suspected, that selective breeding has driven the THCA-synthase pathway into major prevalence, bottlenecking genetic diversity and basically nullifying any quantifiable difference from a cannabinoidal (did I just make up a word?) aspect between different strains, or even whole taxonomies like "indica" vs "sativa".

There was a pretty interesting part I don't really understand, but they said their statistics revealed the presence of some cannabinoid synthase pathways that they did not have models to test for. I'll just have to take their word for it though, because the jargon they used to support that idea was indecipherable.

Basically some math geek stuff was the only new information I could gleam.

 

[Papageno]

Word...the abstract was basically well duh... and great... so you gonna measure the fact that stoners are stupid and fuck up the genetics.

And oh yeah by the way we have shown shown there is a bunch we haven't studied.

Think I am gonna go load a bong.

 

[Felix the Dog]

I found it nteresting. It suggests that marijuana chenistry is more complex than is known, which probably relates to various strains having differing effects despite having the same THC/CDB levels as other strains.