A´int claiming expertise but thought i´d give you some quick searchable terms... Until you get some expertise..

Look for cannabinoids (cbd are often mentioned where seeds are sold as that is important(medical has high cbd wich gives not so much angst etc),that and cbn was both found in the 40s). There are 3 different main groups of cannabinoids, 1 herbal cannabinoids, 2 endogeneous cannabinoids (which is naturally produced and occurs in humans and other manimals and then 3 synthetic cannabinoids which are produced in labs and sold at rc-drug-stores online....
Then there are 2 known types of cannabinoidreceptors (first discovered in 88)cb1 and cb2 and they are coupled to g-protein(thinking of the nobel prize even if their work mostly was done with opiates) as to which go where, search. I really do not know and ain´t really that interested in cannabis, allthough it would be nice to be able to isolate some effects and exclude some.

Maybe these different cannabinoids affects how the delta-9-tetra-hydro-cannabinol is broken down to its different metabolites, the usual is ------> 11-Hydroxy-THC (active)------> 11-nor-9-Carboxy-THC (not active but "from wiki - shown to moderate the effects of THC itself which may help explain the difference in subjective effects seen between occasional and regular users of cannabis") and so on.

Aside from what 4studiesonly stated,

And from what I recall...

There are >60 known alkaloids; in this case cannabinoids found in Cannabis including the aforementioned delta-9 THC, delta-8 THC, Cannabinol, Cannabidiol, along with their metabolites which may be more or less active than the pre-cursors themselves.  In addition to the >60 cannabinoids there are ~120 different terpenes that are thought to be either active on their own, act in a synergistic manner with the cannabinoids or each other, or otherwise modulate or potentiate biological activity in some other manner.

It is not only the presence or quantities of these cannabinoids and terpenes, moreover it is the ratios of each of these compounds in the presence of each other which combine to form the net biological potency / activity.

Knowing the shear numbers of active compounds present in cannabis and that the net effect can depend upon the ratios of each of the compounds relative to each other one can appreciate the near limitless combinations of effects one can achieve through breeding, inbreeding, crossing, back-crossing, mutations, selection, and other genetic manipulations.

I once posted a paper somewhere on the analytical characterization of several popular strains I can try to dig it up. Unfortunately the biological activity of most of the minor cannabinoids and terpenes is unknown, and again trying to make sense of the effects vs. the composition of actives within the herb further confounds the matter.   

Basically the effects of different strains of cannabis are due to an extremely complex and highly diverse combination of biologically active substances many of which have unknown specific activity. These traits have not come about due to the biochemical knowledge of why (for the most part), but simply through trial and error and selective breeding, and crossing. Bioassay being the driving force in addition to other traits such as aroma and flavour. The genetic folks have done a fine job thus far with the industry not knowing shit about the quantities and ratios of the minor compounds in cannabis, I just assume let them keep it up.

much_love

methyl_ethyl

Didn't take long to pull you up on that did he!

Welcome to the Vespiary M_E.

[and it was looking like such a great first post too]

The essence of the post is however correct, of course.

Even the time of harvest relative to the life cycle of the plant will alter the ratios and presence of active compounds.

 While THC is aromatic in a chemical sense of the word I do believe that the active compounds are relatively difficult to detect by smell alone so the overall aroma of the plant is not determined by the active ingredients. Perhaps there is a correlation with THC production and the aromatic terpenoids?

http://www.druglibrary.net/olsen/HEMP/IHA/jiha4208.html

Comparing to MA is also cheating... the number of chiral centres in something like THC or CBD also increases the complexity of a pharmacological study by an order. I suspect one could spend a lifetime studying the activity of the cannabinoids and not ever get to the bottom of it.

Yeah, I graciously accept any flaming for the whole alkaloid statement 

Didn't know what level of street talk was acceptable here.

The Cannabis community, (for whatever reason) has historically referred to THC and other actives as "alkaloids" even in the literature. Since zgoat mentioned it I thought I would simply reply using the same casual naming convention. 

I am relatively new to the cannabis world however am growing to love it. I guess that's what happens when ravers get old and the effects of MDMA are just no longer pleasant, or present.

I will bee more careful in the future.

Its great to see y'all here!!!!

much_love

methyl_ethyl