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This article was the subject of a Wiki Education Foundation-supported course assignment, between 31 March 2020 and 8 June 2020. Further details are available on the course page. Student editor(s): Whaterz.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 10:52, 17 January 2022 (UTC)
I've made some extensive changes to this article, trying to expand it from the bare bones state that it was in. If anyone has any suggestions for improvement or additional information needed, please let me know and I'll try to add it or feel free to just make the changes. I would like to redo some of the images so that they are presented in a consistent style (I used some images from different articles, using them as place-holders for now.) The article is still sparse in the later sections, but at least the current article provides a framework for filling in, I think. Edgar181 05:01, 17 December 2005 (UTC)
I would like a tad more information about how isoprenes combine. The diagram of GPP looks like 2 x DMAPP with the PPi thrown away, but the text says it's IPP + DMAPP. If so, the IPP must have isomerized to DMAPP in the reaction (flipping the double bond 'inward'). So for a complete ignoramus like me looking to learn, this explanation is missing an essential step. Isn't it? And where does the spare PPi go, anyway? ~Anon~
The 'terp' root of the word... where does that come from? Turtles? I suppose the rings can look sort of turtle-like... but seriously, this is something that I have not been able to find out, even after consulting the multivolume Oxford English Dicionary at school.
Any discussion about terpenes and their role in possibly alleopathic plants like salvia leucophylla or eucalyptus?
leathal doses..etc.. —Preceding unsigned comment added by 71.42.147.99 ( talk) 08:08, 18 September 2007 (UTC)
A brief statement about the differences between terpene and terpendoid would be helpful to me. 67.232.173.26 ( talk) 12:15, 26 April 2011 (UTC)IJV
I was reading about beer and noticed that the hops page under "brewing" and the terpene page list different chemicals as the "four major components of hop essential oils". One shows pinene, the other farnesene. I'm not sure if there's a contradiction there, but it should be looked at by someone who knows. Ramireja ( talk) 13:52, 6 January 2012 (UTC)
Many of the examples given are terpenoids rather than terpenes (and therefore do not have the molecular formulas given). I doubt all diterpenes have antimicrobial and antiinflammatory activity; this should probably read "Some are known to be antimicrobial and antiinflammatory." In norisoprenoids peroxydases should be peroxidases. Glycosidases would not produce norisoprenoids. 69.72.92.118 ( talk) 05:42, 10 September 2014 (UTC)
"Terpenes are derived biosynthetically from units of isoprene"
I don't think this phrase is entirely accurate because terpenes are not actually built up from isoprene units. This is clarified in the next paragraph where the article talks about biosynthesis from IPP and DMAPP.
I think it should be clarified that the isoprene rule for predicting the structure and that it is not descriptive of the biosynthetic pathway.
For example, it could say: "Terpenes can be viewed as oligomers of five carbon isoprene units, with the formula C5H8" Beanstash ( talk) 18:22, 18 September 2014 (UTC)
(1) Were aromatic compounds really named for their strong aromas? The aromaticity article says both a qualified, careful no (at the top) and yes (in the body). The terpene article says yes.
(2) Is it really true that terpenes are often (chemically speaking) aromatic? The aromaticity article says no (at the top), the terpene article says yes (at the top).
(3) Do strong-smelling substances and/or terpenes really have a protective function due to their ability to drive off parasites? The terpene article says yes, but in view of the other doubtful statements about strong aromas, I'd like to see some evidence. 84.227.252.224 ( talk) 20:38, 14 October 2014 (UTC)
When organic chemists talk about aromaticity, they are talking about conjugated rings with alternating single and double carbon-carbon bonds. They do not mean to imply odoriferous, a more precise term for the widespread character of terpenes. The important characteristics of 'aromatic' compounds (as used by organic chemists) are their significant absorption in the ultraviolet spectrum and their chemical reactivity. Many polynuclear aromatic compounds (PNAs) are so large that they have little vapor pressure and so have little odor. The word aromatic in this context is a holdover from early chemists' generalizations.
I would like to see the difference between cannabis and non cannabis derived terpenes and a break down of their common uses. Mr Terpenes — Preceding unsigned comment added by 2601:6c1:c000:3370:6923:7c0c:e965:a23b ( talk • contribs)
This artyicle says how terpenes are biosynthaszed, but I did not see an explication of what they are. At a minimum I recommend including the statement from the page Category:Terpenes and terpenoids, "A terpene is a naturally occurring hydrocarbon based on combinations of the isoprene unit." I also recommend including a link to this very helpful page, should there be a way to do that Category:Terpenes and terpenoids.
I don't know why this article has so much to say about terpenoids when there is a separate article about them, but if the terpenoid material must stay, I suggest also including the other statement, "Terpenoids are compounds related to terpenes, which may include some oxygen functionality or some rearrangement, however, the two terms are often used interchangeably." Page Notes ( talk) 13:10, 15 April 2019 (UTC)
Are there about 120 compounds found in Cannabis, or 120 terpenes & terpenoids found in Cannabis?
Terpenes are a vast and interesting class of compounds. I could write a book on this topic and never need to go into this kind of detail. I think this section is abstracted from someone’s PhD dissertation. It dominates the article with intellectual obtuseness. Really. I’m very much more chemically literate than the average American college science graduate, and this section is non-accessible. It has to go. It could be replaced for the average high school or community college American with a one accessible vernacular paragraph about plant synthesis. To write such a paragraph is a substantially greater challenge than the abstract here. Sbalfour ( talk) 21:46, 3 November 2020 (UTC)
The text says: "Terpenes are derived biosynthetically from units of isopentenyl pyrophosphate (IPP)." And this rather complex organic substance IPP magically appears in the water, soil or air? If it doesn't, where does it come from? If plants makes it (dubious), convince me. I'm not a PhD biochemist, but have a decent grasp of organic chemistry. There's a big chunk of stuff (like the most important part of the synthesis) missing here. Sbalfour ( talk) 18:47, 6 November 2020 (UTC)
A large block of info on the general properties of these compounds is missing: i.e. in addition to being smelly and oily generally, they’re highly non-polar liquids at room temperature, so extraction requires petroleum solvents. And they’re often volatile, flammable, toxic, the lighter molecular weight ones may be absorbed thru the skin, and they’re solvents themselves, so how they’re stored and collected needs to be carefully considered. As a practical matter, working with these chemicals requires expertise because they’re not very pleasant, though most of the time we don’t find these outside a chemical laboratory or industrial complex. Turpentine is exemplary of them. Sbalfour ( talk) 11:13, 5 November 2020 (UTC)
Given there are many thousands of named terpenes and terpenoids and probably millions with substantive industrial and commercial applications, do we really want to emphasize recreational cannabinoids? They’re still strictly illegal in most places. I think this whole rather lengthy paragraph would be better placed in the Cannabis sativa article. It’s a subtle brand of ‘aggrandizing erudition’. Sbalfour ( talk) 12:18, 5 November 2020 (UTC)
I don't see why cannabis being "illegal in most places" would make it inherently irrelevant to the article, especially since it's a multibillion-dollar-a-year industry even in the United States alone. I expect cannabis terpenes are the primary terpenes that most non-experts have heard about and the primary terpenes that have been mentioned in the popular press. Therefore, I think it would be odd not to mention cannabis terpenes in an article intended to inform people about terpenes. 2603:8000:D4F0:1D50:8D18:B86D:EFFA:D ( talk) 09:39, 11 March 2024 (UTC)
This section seems superfluous, a whole level 2 section for two sentences? Other organic chemical articles don’t have terminology sections. This is interesting footnote type info. There’s already an elaboration of the term “terpenoid” in the lead, so we don’t need it here. Sbalfour ( talk) 22:49, 5 November 2020 (UTC)
We’ve mentioned beta carotene and α-pinene in the article without any elaboration of what these signify. The isomeric structure of terpenes is evident and prominent, and in various areas like diet and pharmacology, the differences cannot be ignored. I propose some discussion of this on the Structure section. Sbalfour ( talk) 14:36, 6 November 2020 (UTC)
This section is more aptly named "Taxonomy". There's little or nothing here about the structure of terpenes, which would include exposition of isomers, cyclic and chain structures, chirality, homology and possibly crystallography. So I think the section should be split off and renamed, and a separate section Structure added. Sbalfour ( talk) 19:54, 11 November 2020 (UTC)
According to Ullmann's "the industrially most important terpenes":
-- Smokefoot ( talk) 23:36, 13 November 2020 (UTC)
Recent changes to the Applications and Physical and chemical properties sections have lost some information. Specifically, turpentine is for all practical (and even laboratory purposes) pinene, with a few percent volatile contaminants, and the original statement noted the constituents. That has been lost - turpentine is not a generic mixture of turpenes. In the other section, the statements on volatility, miscibility and molecular weight versus volatility were lost. Miscibility is a property separate from solubility, as anyone who has tried to rinse away turpentine with water can readily note. Miscibility is about density, whereas solubility is about polarization. I'm rapidly enlarging the section on properties, and expect it to grow by a factor of 10 or even 20, though I'm starting modestly. So loss or compression of information is not the way to go here. Sbalfour ( talk) 19:14, 15 November 2020 (UTC)
Glad to have some help. I’m not a chemist, but have reasonable general chemistry background. I probably wouldn’t blow up a lab. We’re creeping into the general area of chirality and isomerization in two different sections, and yah, it’s both complex and rather vital. And yes, I agree the biosynthesis section needs a little reorg, and I’m worried about accessibility there. If I can’t understand it with a modest chemical background, the average reader is lost. Sbalfour ( talk) 06:50, 16 November 2020 (UTC)
I know isoprene doesn't have anything to do with the chemistry of terpenes, and I didn’t introduce the precept, someone else sourced it, probably from an elementary text. And calling isoprene a “hemiterpene” is belaboring the point. I like the idea that terpenes are bundles of C5H8 units, though they don’t decompose that way and you don’t build anything starting with isoprene. I’ll see if I can backtrack on it. Sbalfour ( talk) 07:17, 16 November 2020 (UTC)
In any case, take a try. Big articles take effort. Thanks for the robust feedback. Best wishes, -- Smokefoot ( talk) 19:31, 26 November 2020 (UTC)
The second sentence of the Biosynthesis section reads "The isoprene units are provided from isoprenyl pyrophosphate and dimethylallyl pyrophosphate, which exist in equilibrium." But according to the article to which both those links lead, they are two names for the same substance. Maproom ( talk) 22:20, 26 November 2020 (UTC)
I'm not sure what verbose paragraph mentioned above was removed, but the total absence of any mention of the cannabis plant seems like a flaw in this article. Terpenes are (I believe; I'll do the research unless it becomes clear that my change will be reverted) a major component of the effect of cannabis (that is, THC + different native cannabis terpenes can have significantly different psychological effects on humans). Since marijuana is becoming increasingly legal at the state level in the US (and has been effectively legal in Holland and India (a few governmental bhang shops) for a few decades), that seems to be a non-objection. As such, a sentence or two in the "Biological Function" or "Applications" section seems appropriate. Terpenes might (I don't know) even be relevant to the medical uses of cannabis; that would be another relevant area of research.
There are people (such as me) who will do a Wikipedia search on "terpene" to understand their role in the effects of cannabis. It is a reasonable question, and the current article provides *no* relevant information (or any link to a relevant Wikipedia cannabis article).
Thoughts/comments? Finney1234 ( talk) 02:13, 21 August 2021 (UTC)
Not totally surprisingly, some deletions have occurred on the cannabis paragraph in the Terpene article.
1. I consider it important that cannabis be referenced in this article; cannabis is one of the most frequent topics invoked by "terpenes" (do a Google search). Someone who looks up "terpene" for that common reason needs to have some factual information provided.
2. Ferber et al. (2020) is a review article, with 107 primary sources.
3. The 2017 Russo & Marcu review article contains a summary (200 primary sources) of experimentation related to the "entourage" effect. The quote added by 72.249.250.57 is in the abstract of the article, but a (careful) read of the (technical) article shows that that quoted sentence is necessarily based on in-vitro and animal studies, as there are virtually *no* clinical experiments on humans (which is what the original sentence referred to). E.g., Russo's "Conclusion" states "Clinical trials that examine synergistic effects of cannabinoid components are sorely needed". So, currently, it is not known whether the hypothesis is true or false in humans.
4. The widely hypothesized effect of terpenes on cannabinoids is definitely an "application" in the cannabis growth and edibles industry. Again, do a Google search. Finney1234 ( talk) 21:15, 5 October 2021 (UTC)
About a year ago, the lede was fuller, and much more informative. We've lost about 80-90% of it, and I don't know why. Here's what was there:
Terpenes ( /ˈtɜːrpiːn/) are a large and diverse class of hydrocarbons, produced by a variety of plants, particularly conifers, and by some insects. [1] [2] They often have a strong odor and may protect their hosts by deterring herbivores and by attracting predators and parasites of herbivores. [3] [4]
Terpenes are the major components of rosin and of turpentine produced from resin. They and their derivatives are the primary constituents of the essential oils of many types of plants and flowers. [5] Essential oils are used widely as fragrances in perfumery and traditional medicine, such as aromatherapy.
Terpenes are also major biosynthetic building blocks. Steroids, for example, are derivatives of the triterpene squalene. Synthetic variations and derivatives of natural terpenes also greatly expand the variety of aromas used in perfumery and flavors used in food additives. Alkaloids are obtained by substituting nitrogen atoms for one or more carbon atoms in a terpene.
Extraction of terpenes from plants directly is tedious and labor intensive, so modern industrial processes are used to synthesize them from petrochemicals and byproducts of paper pulp manufacturing.
Terpenes may be conceptualized as consisting of building blocks called isoprenes. The simplest terpene is a pair of isoprenes with formula C10H16. One such simple terpene is pinene, a component of cannabis extracts with a pine forest scent.
"Terpene" is often used interchangeably to refer to the larger class "terpenoid" obtained by substituting (usually oxygen-containing) functional groups for some of the hydrogens in a terpene. Particularly, terpene is often used broadly to refer to terpene alcohols such as linalool.
The current lede is patently deficient, since it does not summarize any part of the article or major sections. Maybe the old lede had deficiencies, but I think it plausible when the current one isn't. I propose replacing the current lede with the old one, and if anyone objects, state exactly what is missing or inaccurate, and let's move to improve it.
Sbalfour ( talk) 23:40, 4 April 2022 (UTC)
Also as currently stated (C5H8)n, the definition of terpene in the lede would include isoprene, correct? I'm going to add n > 1 in the definition and if I've missed something, I'm sure someone will edit it out quicker than a reference to the sticky icky. briardew ( talk) 14:11, 6 November 2022 (UTC)
References
Crot
was invoked but never defined (see the
help page).I am reinstating the sentence about the "Entourage Effect" theory removed recently (for the 2nd time, arbitrarily) by editor Zefr. This was well established as having MEDRS quality review resources back in October, 2021. The theory that terpenes may alter the psychological effects of cannabis is very widespread (do a Google search on "terpene"; about 5 of the first 10 results will involve this), so it is important to have it mentioned here, and to provide a summary of the current scientific evidence related to it. (It will be interesting to see what future clinical research shows.) Finney1234 ( talk) 13:41, 17 July 2022 (UTC)
_______________________________________________________
The deleted sentence (now removed by a second editor ( Smokefoot), so I can't fight it) is the following:
"Terpenes (and terpenoids) are prevalent in cannabis (marijuana) and have been postulated to modulate the medicinal or psychological effects of cannabinoids (e.g., THC or CBD) in humans; this is often referred to as the "entourage effect". However, there is currently minimal human clinical data supporting this hypothesis."
Note that this paragraph, with MEDRS review sources, has existed in the article for 9 months, following earlier discussion with both of the editors involved in the current deletion. As such, the paragraph had effectively reached consensus. The current removal is random.
A Google search on "terpene" clearly demonstrates that their presence in cannabis is one of the dominant topics involving "terpenes". The first 5 links that show up in a Google search all refer to the "entourage effect", the claim that terpenes modify the effects of THC. My attempt to provide scientific data that there is currently *no* human clinical evidence supporting this widespread claim has now been removed. The cannabis industry thanks you for your assistance. Finney1234 ( talk) 16:00, 17 July 2022 (UTC)
Should the following two MEDRS referenced sentences ( [1] diff with references) be included in the article?
"Terpenes (and terpenoids) are prevalent in cannabis (marijuana) and have been postulated to modulate the medicinal or psychological effects of cannabinoids (e.g., THC or CBD) in humans; this is often referred to as the "entourage effect". However, there is currently minimal human clinical data supporting this hypothesis." Finney1234 ( talk) 14:32, 26 July 2022 (UTC)
This
level-5 vital article is rated B-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||
|
This article was the subject of a Wiki Education Foundation-supported course assignment, between 31 March 2020 and 8 June 2020. Further details are available on the course page. Student editor(s): Whaterz.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 10:52, 17 January 2022 (UTC)
I've made some extensive changes to this article, trying to expand it from the bare bones state that it was in. If anyone has any suggestions for improvement or additional information needed, please let me know and I'll try to add it or feel free to just make the changes. I would like to redo some of the images so that they are presented in a consistent style (I used some images from different articles, using them as place-holders for now.) The article is still sparse in the later sections, but at least the current article provides a framework for filling in, I think. Edgar181 05:01, 17 December 2005 (UTC)
I would like a tad more information about how isoprenes combine. The diagram of GPP looks like 2 x DMAPP with the PPi thrown away, but the text says it's IPP + DMAPP. If so, the IPP must have isomerized to DMAPP in the reaction (flipping the double bond 'inward'). So for a complete ignoramus like me looking to learn, this explanation is missing an essential step. Isn't it? And where does the spare PPi go, anyway? ~Anon~
The 'terp' root of the word... where does that come from? Turtles? I suppose the rings can look sort of turtle-like... but seriously, this is something that I have not been able to find out, even after consulting the multivolume Oxford English Dicionary at school.
Any discussion about terpenes and their role in possibly alleopathic plants like salvia leucophylla or eucalyptus?
leathal doses..etc.. —Preceding unsigned comment added by 71.42.147.99 ( talk) 08:08, 18 September 2007 (UTC)
A brief statement about the differences between terpene and terpendoid would be helpful to me. 67.232.173.26 ( talk) 12:15, 26 April 2011 (UTC)IJV
I was reading about beer and noticed that the hops page under "brewing" and the terpene page list different chemicals as the "four major components of hop essential oils". One shows pinene, the other farnesene. I'm not sure if there's a contradiction there, but it should be looked at by someone who knows. Ramireja ( talk) 13:52, 6 January 2012 (UTC)
Many of the examples given are terpenoids rather than terpenes (and therefore do not have the molecular formulas given). I doubt all diterpenes have antimicrobial and antiinflammatory activity; this should probably read "Some are known to be antimicrobial and antiinflammatory." In norisoprenoids peroxydases should be peroxidases. Glycosidases would not produce norisoprenoids. 69.72.92.118 ( talk) 05:42, 10 September 2014 (UTC)
"Terpenes are derived biosynthetically from units of isoprene"
I don't think this phrase is entirely accurate because terpenes are not actually built up from isoprene units. This is clarified in the next paragraph where the article talks about biosynthesis from IPP and DMAPP.
I think it should be clarified that the isoprene rule for predicting the structure and that it is not descriptive of the biosynthetic pathway.
For example, it could say: "Terpenes can be viewed as oligomers of five carbon isoprene units, with the formula C5H8" Beanstash ( talk) 18:22, 18 September 2014 (UTC)
(1) Were aromatic compounds really named for their strong aromas? The aromaticity article says both a qualified, careful no (at the top) and yes (in the body). The terpene article says yes.
(2) Is it really true that terpenes are often (chemically speaking) aromatic? The aromaticity article says no (at the top), the terpene article says yes (at the top).
(3) Do strong-smelling substances and/or terpenes really have a protective function due to their ability to drive off parasites? The terpene article says yes, but in view of the other doubtful statements about strong aromas, I'd like to see some evidence. 84.227.252.224 ( talk) 20:38, 14 October 2014 (UTC)
When organic chemists talk about aromaticity, they are talking about conjugated rings with alternating single and double carbon-carbon bonds. They do not mean to imply odoriferous, a more precise term for the widespread character of terpenes. The important characteristics of 'aromatic' compounds (as used by organic chemists) are their significant absorption in the ultraviolet spectrum and their chemical reactivity. Many polynuclear aromatic compounds (PNAs) are so large that they have little vapor pressure and so have little odor. The word aromatic in this context is a holdover from early chemists' generalizations.
I would like to see the difference between cannabis and non cannabis derived terpenes and a break down of their common uses. Mr Terpenes — Preceding unsigned comment added by 2601:6c1:c000:3370:6923:7c0c:e965:a23b ( talk • contribs)
This artyicle says how terpenes are biosynthaszed, but I did not see an explication of what they are. At a minimum I recommend including the statement from the page Category:Terpenes and terpenoids, "A terpene is a naturally occurring hydrocarbon based on combinations of the isoprene unit." I also recommend including a link to this very helpful page, should there be a way to do that Category:Terpenes and terpenoids.
I don't know why this article has so much to say about terpenoids when there is a separate article about them, but if the terpenoid material must stay, I suggest also including the other statement, "Terpenoids are compounds related to terpenes, which may include some oxygen functionality or some rearrangement, however, the two terms are often used interchangeably." Page Notes ( talk) 13:10, 15 April 2019 (UTC)
Are there about 120 compounds found in Cannabis, or 120 terpenes & terpenoids found in Cannabis?
Terpenes are a vast and interesting class of compounds. I could write a book on this topic and never need to go into this kind of detail. I think this section is abstracted from someone’s PhD dissertation. It dominates the article with intellectual obtuseness. Really. I’m very much more chemically literate than the average American college science graduate, and this section is non-accessible. It has to go. It could be replaced for the average high school or community college American with a one accessible vernacular paragraph about plant synthesis. To write such a paragraph is a substantially greater challenge than the abstract here. Sbalfour ( talk) 21:46, 3 November 2020 (UTC)
The text says: "Terpenes are derived biosynthetically from units of isopentenyl pyrophosphate (IPP)." And this rather complex organic substance IPP magically appears in the water, soil or air? If it doesn't, where does it come from? If plants makes it (dubious), convince me. I'm not a PhD biochemist, but have a decent grasp of organic chemistry. There's a big chunk of stuff (like the most important part of the synthesis) missing here. Sbalfour ( talk) 18:47, 6 November 2020 (UTC)
A large block of info on the general properties of these compounds is missing: i.e. in addition to being smelly and oily generally, they’re highly non-polar liquids at room temperature, so extraction requires petroleum solvents. And they’re often volatile, flammable, toxic, the lighter molecular weight ones may be absorbed thru the skin, and they’re solvents themselves, so how they’re stored and collected needs to be carefully considered. As a practical matter, working with these chemicals requires expertise because they’re not very pleasant, though most of the time we don’t find these outside a chemical laboratory or industrial complex. Turpentine is exemplary of them. Sbalfour ( talk) 11:13, 5 November 2020 (UTC)
Given there are many thousands of named terpenes and terpenoids and probably millions with substantive industrial and commercial applications, do we really want to emphasize recreational cannabinoids? They’re still strictly illegal in most places. I think this whole rather lengthy paragraph would be better placed in the Cannabis sativa article. It’s a subtle brand of ‘aggrandizing erudition’. Sbalfour ( talk) 12:18, 5 November 2020 (UTC)
I don't see why cannabis being "illegal in most places" would make it inherently irrelevant to the article, especially since it's a multibillion-dollar-a-year industry even in the United States alone. I expect cannabis terpenes are the primary terpenes that most non-experts have heard about and the primary terpenes that have been mentioned in the popular press. Therefore, I think it would be odd not to mention cannabis terpenes in an article intended to inform people about terpenes. 2603:8000:D4F0:1D50:8D18:B86D:EFFA:D ( talk) 09:39, 11 March 2024 (UTC)
This section seems superfluous, a whole level 2 section for two sentences? Other organic chemical articles don’t have terminology sections. This is interesting footnote type info. There’s already an elaboration of the term “terpenoid” in the lead, so we don’t need it here. Sbalfour ( talk) 22:49, 5 November 2020 (UTC)
We’ve mentioned beta carotene and α-pinene in the article without any elaboration of what these signify. The isomeric structure of terpenes is evident and prominent, and in various areas like diet and pharmacology, the differences cannot be ignored. I propose some discussion of this on the Structure section. Sbalfour ( talk) 14:36, 6 November 2020 (UTC)
This section is more aptly named "Taxonomy". There's little or nothing here about the structure of terpenes, which would include exposition of isomers, cyclic and chain structures, chirality, homology and possibly crystallography. So I think the section should be split off and renamed, and a separate section Structure added. Sbalfour ( talk) 19:54, 11 November 2020 (UTC)
According to Ullmann's "the industrially most important terpenes":
-- Smokefoot ( talk) 23:36, 13 November 2020 (UTC)
Recent changes to the Applications and Physical and chemical properties sections have lost some information. Specifically, turpentine is for all practical (and even laboratory purposes) pinene, with a few percent volatile contaminants, and the original statement noted the constituents. That has been lost - turpentine is not a generic mixture of turpenes. In the other section, the statements on volatility, miscibility and molecular weight versus volatility were lost. Miscibility is a property separate from solubility, as anyone who has tried to rinse away turpentine with water can readily note. Miscibility is about density, whereas solubility is about polarization. I'm rapidly enlarging the section on properties, and expect it to grow by a factor of 10 or even 20, though I'm starting modestly. So loss or compression of information is not the way to go here. Sbalfour ( talk) 19:14, 15 November 2020 (UTC)
Glad to have some help. I’m not a chemist, but have reasonable general chemistry background. I probably wouldn’t blow up a lab. We’re creeping into the general area of chirality and isomerization in two different sections, and yah, it’s both complex and rather vital. And yes, I agree the biosynthesis section needs a little reorg, and I’m worried about accessibility there. If I can’t understand it with a modest chemical background, the average reader is lost. Sbalfour ( talk) 06:50, 16 November 2020 (UTC)
I know isoprene doesn't have anything to do with the chemistry of terpenes, and I didn’t introduce the precept, someone else sourced it, probably from an elementary text. And calling isoprene a “hemiterpene” is belaboring the point. I like the idea that terpenes are bundles of C5H8 units, though they don’t decompose that way and you don’t build anything starting with isoprene. I’ll see if I can backtrack on it. Sbalfour ( talk) 07:17, 16 November 2020 (UTC)
In any case, take a try. Big articles take effort. Thanks for the robust feedback. Best wishes, -- Smokefoot ( talk) 19:31, 26 November 2020 (UTC)
The second sentence of the Biosynthesis section reads "The isoprene units are provided from isoprenyl pyrophosphate and dimethylallyl pyrophosphate, which exist in equilibrium." But according to the article to which both those links lead, they are two names for the same substance. Maproom ( talk) 22:20, 26 November 2020 (UTC)
I'm not sure what verbose paragraph mentioned above was removed, but the total absence of any mention of the cannabis plant seems like a flaw in this article. Terpenes are (I believe; I'll do the research unless it becomes clear that my change will be reverted) a major component of the effect of cannabis (that is, THC + different native cannabis terpenes can have significantly different psychological effects on humans). Since marijuana is becoming increasingly legal at the state level in the US (and has been effectively legal in Holland and India (a few governmental bhang shops) for a few decades), that seems to be a non-objection. As such, a sentence or two in the "Biological Function" or "Applications" section seems appropriate. Terpenes might (I don't know) even be relevant to the medical uses of cannabis; that would be another relevant area of research.
There are people (such as me) who will do a Wikipedia search on "terpene" to understand their role in the effects of cannabis. It is a reasonable question, and the current article provides *no* relevant information (or any link to a relevant Wikipedia cannabis article).
Thoughts/comments? Finney1234 ( talk) 02:13, 21 August 2021 (UTC)
Not totally surprisingly, some deletions have occurred on the cannabis paragraph in the Terpene article.
1. I consider it important that cannabis be referenced in this article; cannabis is one of the most frequent topics invoked by "terpenes" (do a Google search). Someone who looks up "terpene" for that common reason needs to have some factual information provided.
2. Ferber et al. (2020) is a review article, with 107 primary sources.
3. The 2017 Russo & Marcu review article contains a summary (200 primary sources) of experimentation related to the "entourage" effect. The quote added by 72.249.250.57 is in the abstract of the article, but a (careful) read of the (technical) article shows that that quoted sentence is necessarily based on in-vitro and animal studies, as there are virtually *no* clinical experiments on humans (which is what the original sentence referred to). E.g., Russo's "Conclusion" states "Clinical trials that examine synergistic effects of cannabinoid components are sorely needed". So, currently, it is not known whether the hypothesis is true or false in humans.
4. The widely hypothesized effect of terpenes on cannabinoids is definitely an "application" in the cannabis growth and edibles industry. Again, do a Google search. Finney1234 ( talk) 21:15, 5 October 2021 (UTC)
About a year ago, the lede was fuller, and much more informative. We've lost about 80-90% of it, and I don't know why. Here's what was there:
Terpenes ( /ˈtɜːrpiːn/) are a large and diverse class of hydrocarbons, produced by a variety of plants, particularly conifers, and by some insects. [1] [2] They often have a strong odor and may protect their hosts by deterring herbivores and by attracting predators and parasites of herbivores. [3] [4]
Terpenes are the major components of rosin and of turpentine produced from resin. They and their derivatives are the primary constituents of the essential oils of many types of plants and flowers. [5] Essential oils are used widely as fragrances in perfumery and traditional medicine, such as aromatherapy.
Terpenes are also major biosynthetic building blocks. Steroids, for example, are derivatives of the triterpene squalene. Synthetic variations and derivatives of natural terpenes also greatly expand the variety of aromas used in perfumery and flavors used in food additives. Alkaloids are obtained by substituting nitrogen atoms for one or more carbon atoms in a terpene.
Extraction of terpenes from plants directly is tedious and labor intensive, so modern industrial processes are used to synthesize them from petrochemicals and byproducts of paper pulp manufacturing.
Terpenes may be conceptualized as consisting of building blocks called isoprenes. The simplest terpene is a pair of isoprenes with formula C10H16. One such simple terpene is pinene, a component of cannabis extracts with a pine forest scent.
"Terpene" is often used interchangeably to refer to the larger class "terpenoid" obtained by substituting (usually oxygen-containing) functional groups for some of the hydrogens in a terpene. Particularly, terpene is often used broadly to refer to terpene alcohols such as linalool.
The current lede is patently deficient, since it does not summarize any part of the article or major sections. Maybe the old lede had deficiencies, but I think it plausible when the current one isn't. I propose replacing the current lede with the old one, and if anyone objects, state exactly what is missing or inaccurate, and let's move to improve it.
Sbalfour ( talk) 23:40, 4 April 2022 (UTC)
Also as currently stated (C5H8)n, the definition of terpene in the lede would include isoprene, correct? I'm going to add n > 1 in the definition and if I've missed something, I'm sure someone will edit it out quicker than a reference to the sticky icky. briardew ( talk) 14:11, 6 November 2022 (UTC)
References
Crot
was invoked but never defined (see the
help page).I am reinstating the sentence about the "Entourage Effect" theory removed recently (for the 2nd time, arbitrarily) by editor Zefr. This was well established as having MEDRS quality review resources back in October, 2021. The theory that terpenes may alter the psychological effects of cannabis is very widespread (do a Google search on "terpene"; about 5 of the first 10 results will involve this), so it is important to have it mentioned here, and to provide a summary of the current scientific evidence related to it. (It will be interesting to see what future clinical research shows.) Finney1234 ( talk) 13:41, 17 July 2022 (UTC)
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The deleted sentence (now removed by a second editor ( Smokefoot), so I can't fight it) is the following:
"Terpenes (and terpenoids) are prevalent in cannabis (marijuana) and have been postulated to modulate the medicinal or psychological effects of cannabinoids (e.g., THC or CBD) in humans; this is often referred to as the "entourage effect". However, there is currently minimal human clinical data supporting this hypothesis."
Note that this paragraph, with MEDRS review sources, has existed in the article for 9 months, following earlier discussion with both of the editors involved in the current deletion. As such, the paragraph had effectively reached consensus. The current removal is random.
A Google search on "terpene" clearly demonstrates that their presence in cannabis is one of the dominant topics involving "terpenes". The first 5 links that show up in a Google search all refer to the "entourage effect", the claim that terpenes modify the effects of THC. My attempt to provide scientific data that there is currently *no* human clinical evidence supporting this widespread claim has now been removed. The cannabis industry thanks you for your assistance. Finney1234 ( talk) 16:00, 17 July 2022 (UTC)
Should the following two MEDRS referenced sentences ( [1] diff with references) be included in the article?
"Terpenes (and terpenoids) are prevalent in cannabis (marijuana) and have been postulated to modulate the medicinal or psychological effects of cannabinoids (e.g., THC or CBD) in humans; this is often referred to as the "entourage effect". However, there is currently minimal human clinical data supporting this hypothesis." Finney1234 ( talk) 14:32, 26 July 2022 (UTC)