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This article contains a translation of Алкалоиды from ru.wikipedia. ( 366360255 et seq.) |
A fact from Alkaloid appeared on Wikipedia's
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Did you know column on 9 June 2010 (
check views). The text of the entry was as follows:
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There's no reason to include a picture of a decapitated and deformed animal in this article. The image serves no educational or informative value for the subject at hand. The article already clearly explains that the substance in question is known to cause deformities. A reader does not gain any better education on the topic by being subjected to the image. Its inclusion here serves NO purpose, other than to create shock. — Preceding unsigned comment added by 2600:4040:B078:6C00:7CC0:956C:48D:58E4 ( talk) 10:56, 5 July 2023 (UTC)
Why is this substance in two groups? __ meco 01:34, 15 July 2006 (UTC)
I added an example and citation of an organism that uses alkaloids for protection: Utetheisa ornatrix to “The Biological Role” section. Kzyoung ( talk) 20:18, 14 November 2013 (UTC)
The {{ Commons}} box looks awful at the top. Can we please not put it there? — Keenan Pepper 09:52, 4 August 2006 (UTC)
it does not appear naturally, so why is it included here? if noone objects, I'll remove it. -- Rwst 08:07, 7 August 2006 (UTC)
Historically to be considered an alkaloid a chemical had to:
1 come from a plant 2 contain at least 1 nitrogen atom in its structure 3 have a physiological effect on animals
A minor synthetic change doesn't matter,
Heroin is not found in nature, but is a simple derivative of morphine, and is an alkaloid.
So is LSD.
75.15.209.116 ( talk)jimmy2000 Dec 2011 —Preceding undated comment added 07:51, 4 December 2011 (UTC).
The article on cocaine has "The name comes from the name of the coca plant plus the alkaloid suffix -ine". Can this suffix use be confirmed and documented here? TIA
Jerome Potts 03:35, 21 August 2006 (UTC)
I think noting that many trivial names for alkaloids end in "-ine" is probably uncontroversial enough to be added without a source, although sourcing it would be preferable. We could say something like "many alkaloids have names ending in -amine or simply -ine" for example. Calling "-ine" the alkaloid suffix might not be the best practice though, as many synthetic amines end in "ine" (e.g. drugs with names ending in "amine" or "-caine"). The use of "-in" would be good to document also. Names with "-in", when they occur, seem to be applied to alkaloids discovered in animals (bufotenin aka bufotenine) or fungi (psilocybin), but I think "-ine" may even be more common.-- Eloil 01:42, 26 April 2007 (UTC)
I'm adding Category: Chemistry to this article, for obvious reasons. Mihovil 18:42, 30 August 2006 (UTC)
What about pyrrolizidine alkaloids? Does this category merit a mention in the list of alkaloid groups? They are of interest for their hepatotoxicity and have already been mentioned in a number of other articles- for example, borage, comfrey, fuki, Roger Adams. Krnntp 17:20, 1 September 2006 (UTC)
I am a novice on this area but would like someone to direct me what to analyse for (not myself but competent biochemists) if I would like to look at the metabolites of an alkaloid, mesembrine. If I want to see if it was taken up in animal metabolic pathways when consumed, what would I look for. or if I need to analyse for residues. Could anyone give me clues? Pstrydom Pstrydom 13:59, 19 October 2006 (UTC)pstrydom
The classification section could use a bit of cleanup. It is not clear that the examples given are not exhaustive. Also, what are the criteria for choosing specific compounds to list as examples? If it is by their importance, I would suggest adding Synephrine. With the FDA's restrictions on Ephedrine, Synephrine is becoming a popular alternative despite the fact that it may be just as dangerous. 70.100.3.62 03:20, 2 November 2006 (UTC)
If anyone has time, the {{ Alkaloids}} would really benefit from your expertise. Thanks! :) Willow 19:07, 27 January 2007 (UTC)
Currently the article opens as follows:
The wording of the first sentence seems to suggest that the "strict" definition (must be found in plants) is the most correct somehow, but the third sentence suggests that this interpretation was predated by a much broader one (any nitrogen-containing base). My feeling is that we should go by usage and not by someone's conservative interpretation of what should "strictly" be called an alkaloid. If "alkaloid" is widely used in scientific literature to describe nitrogen-containing bases that have been found in animals or fungi but not (or not yet) in plants, then I think those chemicals are alkaloids. This usage might be considered mildly controversial by some, which is worth noting, but I don't think we're justified in implying it's not "strictly" correct.
from Wiktionary:alkaloid:
The "heterocyclic" qualifier is interesting. Phenethylamine alkaloids like mescaline have only carbons in their rings, and I'd guess there are many other example non-heterocyclic alkaloids. Are there alkaloids with no rings at all? It seems like most have some type of ring structure. -- Eloil 09:51, 1 April 2007 (UTC)
An alkaloid always has some type of physiological effect on animals.
So amino acid's generally don't meet that definition. 75.15.209.116 ( talk)jimmy2000 dec 2011
Mesembrine is Alkaloid which can be added. —Preceding unsigned comment added by 196.209.60.35 ( talk) 17:36, 7 June 2008 (UTC)
I think the classification in the article needs some revising. Namely, the quaternary ammonium salts are listed as if they were part of steroids... and they aren't:) In either way they're not terpenoids so they would better fit under separate entry somewhere below. And also the Indolic alkaloids. Reserpine and yohimbine have no more relation to beta-carbolines than to simple tryptamines. They'd better be listed as a separate subgroup amongst other indoles, possibly "Yohimbans". Mytraginine has also much similarity to that particular structure. Vinca alkaloids are too indolic, so why not place them as a sub to indoles? Same about Strychnine and Ibogaine, they deserve a mention as structurally unrelated Indoles. And also, capsaicin is not an alkaloid at all, it's a vanilloid, not an amine (it's rather an amide) and thus not basic. Correct me if I'm wrong. Angsaar ( talk) 20:26, 18 July 2008 (UTC)
Fixed that, now saying it is a "steroid alkaloid", containing both a nitrogen, and a steroid skeleton as components of the structure. Linking them to "steroid" is misleading. 70.137.149.127 ( talk) 11:13, 5 August 2008 (UTC)
Regardless of the synthesis pathway, these three differ so much from the structure of the other isoquinoline alkaloids, that a separate category is justified. 70.137.149.127 ( talk) 12:26, 5 August 2008 (UTC)
I have seen the discussion about amides, leading to removal of colchicine. I think that is overzealous, piperine is an amid too, capsaicin too. 70.137.149.127 ( talk) 12:38, 5 August 2008 (UTC)
A more appropriate definition of alkaloids includes the amides. This seems to be in line with current nomenclature. Colchicine should be put back. The xanthines are also alkaloids after all. piperine and capsaicin belong in too. 70.137.180.142 ( talk) 04:59, 9 September 2008 (UTC)
See here
and here
http://www.sciencemadness.org/library/books/the_plant_alkaloids.pdf
Cacycle: your edit reverted for that reason.
70.137.180.142 ( talk) 05:25, 9 September 2008 (UTC)
I would not call the loosening of the definition arbitrary. First we would have to verify the correctness of the current definition in the alkaloid entry. I have given two book references you call sloppy. There are many more. IMO alkaloids are "nitrogen containing small molecules, naturally occuring in plants, animals and fungi, developed for defense, characterized by high physiological activity". This narrows the definition sufficiently from "natural products". In this sense the common amino acids would not be alkaloids, but "domoic acid" would be. Colchicine, piperine and capsaicin would be. The concept is a practical one, I want readers to find things where they expect them, and where they find them in scientific literature. The concept is not only a practical one but also a historical one. The line I follow here is historically founded, I don't want a new but incompatible definition, but we will do what the majority of literature does, even if it appears sloppy. After all the concept of alkaloids was introduced historically, to cover the active nitrogen containing plant substances after they were investigated, it is an ad hoc approach to nomenclature of already existing discoveries, and of a developing topic. If the books count piperine and colchicine as alkaloids, then we do too. 70.137.143.23 ( talk) 21:50, 10 September 2008 (UTC)
Please take also a look at the other ref I have given above, which is a modern teaching book, and what definition it uses. I am also not sure if the IUPHAR definition is strict and trustworthy, indeed what does "normally" mean. And are the pharmacologists competent for providing a definition, or is this a matter to be left to the researchers in the field? I will tag the current definition in the article with a fact tag. Colchicine should be in. You say:
The part "biogenetically related to basic alkaloids" means that they fall under this definition if the basic parent compound has been isolated from natural sources (preferably the same source).
This is OR.
This is for including all family members of alkaloids, even if they are quaternized or N-acetylated. I am not sure if that would include colchicine and it definitely excludes capsaicin.
This is OR too.
Furthermore: The xanthines are amides too, not very basic. The amides are basic too, only weakly. And: "mere teaching books" are good enough for inclusion as a ref. See reliable sources. 70.137.143.23 ( talk) 17:24, 11 September 2008 (UTC)
I think a historical perspective is also welcome in this century old topic; insofar a text book from the 40's would be fine. 90% of the materials is quite a bit dated, as the research of plant alkaloids has been a focus of pharmacology already 100 years ago. Think of the malaria research etc. and the research into modified opium alkaloids. I think we have to look at common and historical use to be useful in general, and not to be more catholic than the pope. 70.137.143.23 ( talk) 18:25, 11 September 2008 (UTC)
For a recent teaching book see here, it still agrees with the old refs:
http://books.google.com.br/books?id=guD67lsXymgC&printsec=frontcover&dq=Modern+Alkaloids.+Structure,+Isolation,+Synthesis+and+Biology&sig=ACfU3U2ItEZqMh72a8Xc_AZGEijQ-i-A_Q
also see the two recent articles I included as a reference. See below. I hate to bring two old book refs, (1906 and 1947), one recent book ref (brand new) and two recent peer reviewed articles, and they are all "arbitrary" and don't understand the issue, "confuse" things etc. 70.137.143.23 ( talk) 01:36, 12 September 2008 (UTC)
Acoording to this ref
http://www.pnas.org/content/103/36/13315.full
capsaicin is an alkaloid, synthesized from vanillylamine by capsaicin synthase. There you are. No OR. 70.137.143.23 ( talk) 18:40, 11 September 2008 (UTC)
Sorry, the REF SAYS THAT IT IS AN ALKALOID (literally). Thats not my funny idea. So they don't know what they are talking? 70.137.143.23 ( talk) 01:48, 12 September 2008 (UTC)
According to this review article
But see also the book sources above. (They are not hippie books, how to grow your own etc. or popular science)
Cacycle: What you are doing here is WP:Synth from the IUPHARM/IUPAC definition, which is rather mushy. (*are NORMALLY not regarded..*)
Now don't tell me all these sources are wrong: 2 teaching books, one peer reviewed primary source, one peer reviewed review article. 70.137.143.23 ( talk) 19:14, 11 September 2008 (UTC)
Further historical context:
Pictet, "The vegetable alkaloids", 1906 (and 1896)
download pdf as a google book here:
says piperine is an alkaloid, weakly basic, does not form salts with weak acids, but does form salts with concentrated mineral acids. These salts are dissociated by water. The book gives in its introduction also a history of alkaloid research and the development of the definition, from initially only pyridine compounds to what we have as of 1906. It also lists, like above book references (Not: "How to grow your own" by M.R. Hippie, The Hippiepress) Colchicine as an alkaloid. This overrides Wp:Synth from the IUPAC definition. 70.137.143.23 ( talk) 20:09, 11 September 2008 (UTC)
Certainly Pictet has not confused salt formation with hydrolysis; neither would I. Read it. 70.137.143.23 ( talk) 01:07, 12 September 2008 (UTC)
What makes you disagree with this ref
http://www.pnas.org/content/103/36/13315.full
and this ref
70.137.143.23 ( talk) 01:05, 12 September 2008 (UTC)
Thats exactly what "Pictet, The vegetable alkaloids, 1906, 1896" says. Formation of salts with strong mineral acids. Also formation of salts ("double salts") with Platinum chloride and others like that. Same for "Henry, The plant alkaloids, 1947". So we may conclude piperine is rightfully an alkaloid, historically, from its basicity, its ability to form salts. 70.137.143.23 ( talk) 15:56, 12 September 2008 (UTC)
Cacycle: look at wp amides for the weak basic character of amides. and: The chemists of the early 20th century KNEW the difference between hydrolysis and salt formation. We are not dealing with k12 students here, and we wikipedia readers usually have a GED. 70.137.143.23 ( talk) 15:56, 12 September 2008 (UTC)
I'm replying to a request for comments at Wikipedia talk:WikiProject Chemistry. All I can say is: Oh, my, this is about as productive as debating the definition of organic compound! (Something on which we have, sadly, spent too much time.) There is no unique definition and the distinction is blurry and arbitrary. You will always find some compounds that are called alkaloids by some authors and not by others. The article should reflect this reality.
One comment about the IUPAC Gold Book reference. I love the Gold Book and cite it a lot, but we should remember what it is: basically a collation of glossaries. IMHO, glossaries are meant to be useful for reference by providing a quick definition that is good enough, but should not be interpreted as "legislation". I've found some definitions in the Gold Book that I think are incomplete or deficient and, although I'm no alkaloid expert I suspect this definition may have its limitations too.
This book could be useful: Alkaloids:Nature's curse or blessing?, pages 1-5 (it's also readable on amazon.com, where I could read pages 5 and 6, which I couldn't read on Google books). The good thing about these pages is that they quote several definitions from the 19th and 20th centuries and compare them. Some focused on the plant origin, some on the basicity, some on the heterocyclic rings, but there were always exceptions. The vague definition that the author ends up proposing is "nitrogen-containing organic substances of natural origin with a greater or lesser degree of basic character". -- Itub ( talk) 09:35, 12 September 2008 (UTC)
- Returning to the question in the title of this section, capsaicin does not fall into any of the three classic types of nitrogen-bearing plant natural products, being neither a true alkaloid, a protoalkaloid, or a pseudoalkaloid. Capsaicin is of limited distribution in Nature and shows pharmacological activity, but it is non-basic, structurally unsophisticated, and not directly derived from an amino acidic precursor. On the other hand, the lack of attributes such as basicity, complexity, and an “amino acidic pedigree” can also be found in compounds commonly perceived as alkaloids. Thus, colchicine is neutral, ephedrine is structurally unsophisticated, and the nitrogen atom of the potato alkaloid solanine is not derived from an amino acid […]. For the sake of clarity and consistency, it seems therefore convenient to adopt the modern definition of alkaloids, and consider capsaicin, as well as alkylamides such as piperine and pellitorine, as such.
I have added some Literary references to alkaloids as seen in some famous novels. I thought this would broaden this interesting topic. I hope no one has a problem with it being included. Please add more to it. Proquence ( talk) 18:31, 22 November 2008 (UTC)
just raised the importance rating from mid to top.personally I don't know how anybody see this topic as mid importance!!! alkaloids are a major class in both pharmaceutical and phytochemistry that include very important drugs like morphine,quinidine and many others in a very long and ever expanding list. I am know jammed with exams so as soon as they are over I'll work on improving it-- 7amada'sback:) ( talk) 17:59, 5 January 2009 (UTC)
Morphine etc. is sometimes grouped with the benzylisoquinoline alkaloids because of its natural synthesis pathway. Morphine, codeine, thebaine, oripavine are however so different in structure from the other opium alkaloids, that they are usually grouped together as phenanthrene alkaloids. They are also pharmacologically different from the others (narcotine, papaverine...) in that they are opioid agonists, while the others are not. Looking at the structure, they are more related to each other than to narcotine etc. See entry "phenanthrene alkaloids" in the list 70.137.172.47 ( talk) 05:02, 21 September 2009 (UTC)
You will find that in pharmacological literature this distinction generally has been made, based on the high structural similarity and receptor action of morphine, codeine,thebaine, oripavine. They really make up a distinct group of substances. Your recent addition of classification and the reference supports a view where biosynthetic pathway, structural similarity and pharmacological action may be criteria in this highly complex question. Separation into the phenanthrene group would be supported by structural and pharmacological relation. 70.137.139.237 ( talk) 20:07, 22 September 2009 (UTC)
Here a recent book source stating that e.g. morphine, codeine etc. contain a hydrophenanthrene nucleus, and that "these phenanthrene alkaloids" are derived from benzylisoquinoline intermediates in the biosynthesis.
page 252. Take a look. I am not making it up. 70.137.139.237 ( talk) 21:22, 22 September 2009 (UTC)
The isoflavones with estrogenic action are a false analogy. In the phenanthrene alkaloids we have a group of opium alkaloids, which are extremely closely related in structure, synthesis pathway AND pharmacological action, but quite distinct from the other opium alkaloids in structure, synthesis pathway AND pharmacological action. The isoflavones, in contrast, have no such close structural relation to the estrogens and no common biosynthetic pathway with the estrogens. There are also synthetic opioids, which have no close relation to the phenanthrene alkaloids, sometimes also called morphinans, and there are many synthetic opioids built around the morphinan skeleton. The structure-activity relationships of morphine like alkaloids and their synthetic derivatives are very well investigated for 100 years. Alone the importance of the morphinan backbone for semisynthetic and synthetic analgetic substances justifies grouping them from the other benzylisoquinoline alkaloids.See Morphinan 70.137.139.237 ( talk) 21:40, 22 September 2009 (UTC) 70.137.139.237 ( talk) 21:40, 22 September 2009 (UTC)
To find the prevailing classification is probably beyond the scope of WP editing, as it would require a review of contemporary literature. Using an existing review would include the task, to find if this existing review came to the prevailing conclusion etc. At least the given reference is recent and it states the morphine and alike alkaloids as phenanthrene alkaloids and as derived from benzylisoquinoline by biosynthetic pathway. They are actually benzylisoquinoline alkaloids by biosynthesis, phenanthrene and morphinan alkaloids as a subgroup. The situation may be similar to the carboline alkaloids, which are also indole alkaloids. If this recent ref treats them as phenanthrene alkaloids, then I don't care if this is maybe a bit outdated. We don't need to know this better than they do. 70.137.169.140 ( talk) 22:38, 23 September 2009 (UTC)
Since when bufotenine is a poison? Tryptamines ( talk) 09:34, 29 March 2012 (UTC)
Is it necessary to have the picture of cyclopia in a sheep in this article? I'm sure I'm not the only person who doesn't like to see unexpected body horror in academic articles! Obviously, the story about the lambs receiving birth defects as a result of their mother eating the alkaloid is important - but does the picture need to be on this page? Is there some way in wiki markup to hide it, on the basis that it might be upsetting to some viewers, so you have to consciously click to see it? Baratron ( talk) 00:43, 24 June 2014 (UTC)
Hello fellow Wikipedians,
I have just added archive links to one external link on
Alkaloid. Please take a moment to review
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Cheers.— cyberbot II Talk to my owner:Online 20:28, 13 July 2015 (UTC)
I changed the solubility description. was originally:
Changed it to slightly and very slightly soluble in water (for the alkaloids, not the salts), corresponding to the Remington's table ( http://pharmlabs.unc.edu/labs/solubility/intro.htm, or http://www.sigmaaldrich.com/united-kingdom/technical-services/solubility.html):
Descriptive term | Volume (ml) of Solvent Needed to Dissolve 1g of Solute |
---|---|
Very soluble | < 1 |
Freely soluble | 1-10 |
Soluble | 10-30 |
Sparingly soluble | 30-100 |
Slightly soluble | 100-1000 |
Very slightly soluble | 1000-10,000 |
Practically insoluble or insoluble | > 10,000 |
In a medical context these substances might be considered highly soluble by some ( for example: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399483/ "Solubility is based on the highest-dose strength of an immediate release product. A drug is considered highly soluble when the highest dose strength is soluble in 250 mL or less of aqueous media over the pH range of 1 to 7.5."), but I doubt this definition is widely used (and is only useful for oral medication, you don't inject someone with 250 ml... ). Prevalence ( talk) 15:17, 22 December 2015 (UTC)
The Actions of Ergot Alkaloids in the table under the Applications heading is completely false. Whether this is by accident or ignorance, it is very misleading and may undermine the credibility of Wikipedia.
Specifically, ergot alkaloids are seldom if ever "sympathomimetic". There are no ergot alkaloids listed within the article Sympathomimetics. Second, ergot alkaloids are predominantly vasoconstricting, not vasodialating. For example, Ergotism is a disease marked by acute and chronic vasoconstriction leading to dry gangrene and vascular dementia after consumption of the alkaloids of the ergot fungus. Third, ergot alkaloids, causing vasoconstriction, are not antihypertensive. The vasoconstriction they cause increases blood pressure directly.
I'll fix it myself in a few weeks if no-one can argue why I shouldn't.
69.92.196.11 ( talk) 18:58, 16 November 2017 (UTC)
Corrected content with information found on the topic's article
Ergoline#Uses
69.92.196.11 (
talk) 15:19, 18 November 2017 (UTC)
I'm looking around for sources that would support the statement with citation [12] in the article that was marked as failed verification. This article implies that a typical alkaloid that inhibits hyperglycemia/diabetes through insulin stimulation is berberine, though that isn't mentioned among the many purported health effects that haven't been tested in humans for that chemical, and it's from J Diabetes Metab Disorder which is cited 4 times on Wikipedia in total. This article from Molecules (journal) says pretty much the same as the previous article, listing all the same alkaloids. Do either of these seem like plausible supporting evidence for the statement that alkaloids are effective against hyperglycemia or diabetes mellitus? Reconrabbit ( talk| edits) 20:25, 15 December 2023 (UTC)
This is the
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Alkaloid article. This is not a forum for general discussion of the article's subject. |
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Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
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This article contains a translation of Алкалоиды from ru.wikipedia. ( 366360255 et seq.) |
A fact from Alkaloid appeared on Wikipedia's
Main Page in the
Did you know column on 9 June 2010 (
check views). The text of the entry was as follows:
|
There's no reason to include a picture of a decapitated and deformed animal in this article. The image serves no educational or informative value for the subject at hand. The article already clearly explains that the substance in question is known to cause deformities. A reader does not gain any better education on the topic by being subjected to the image. Its inclusion here serves NO purpose, other than to create shock. — Preceding unsigned comment added by 2600:4040:B078:6C00:7CC0:956C:48D:58E4 ( talk) 10:56, 5 July 2023 (UTC)
Why is this substance in two groups? __ meco 01:34, 15 July 2006 (UTC)
I added an example and citation of an organism that uses alkaloids for protection: Utetheisa ornatrix to “The Biological Role” section. Kzyoung ( talk) 20:18, 14 November 2013 (UTC)
The {{ Commons}} box looks awful at the top. Can we please not put it there? — Keenan Pepper 09:52, 4 August 2006 (UTC)
it does not appear naturally, so why is it included here? if noone objects, I'll remove it. -- Rwst 08:07, 7 August 2006 (UTC)
Historically to be considered an alkaloid a chemical had to:
1 come from a plant 2 contain at least 1 nitrogen atom in its structure 3 have a physiological effect on animals
A minor synthetic change doesn't matter,
Heroin is not found in nature, but is a simple derivative of morphine, and is an alkaloid.
So is LSD.
75.15.209.116 ( talk)jimmy2000 Dec 2011 —Preceding undated comment added 07:51, 4 December 2011 (UTC).
The article on cocaine has "The name comes from the name of the coca plant plus the alkaloid suffix -ine". Can this suffix use be confirmed and documented here? TIA
Jerome Potts 03:35, 21 August 2006 (UTC)
I think noting that many trivial names for alkaloids end in "-ine" is probably uncontroversial enough to be added without a source, although sourcing it would be preferable. We could say something like "many alkaloids have names ending in -amine or simply -ine" for example. Calling "-ine" the alkaloid suffix might not be the best practice though, as many synthetic amines end in "ine" (e.g. drugs with names ending in "amine" or "-caine"). The use of "-in" would be good to document also. Names with "-in", when they occur, seem to be applied to alkaloids discovered in animals (bufotenin aka bufotenine) or fungi (psilocybin), but I think "-ine" may even be more common.-- Eloil 01:42, 26 April 2007 (UTC)
I'm adding Category: Chemistry to this article, for obvious reasons. Mihovil 18:42, 30 August 2006 (UTC)
What about pyrrolizidine alkaloids? Does this category merit a mention in the list of alkaloid groups? They are of interest for their hepatotoxicity and have already been mentioned in a number of other articles- for example, borage, comfrey, fuki, Roger Adams. Krnntp 17:20, 1 September 2006 (UTC)
I am a novice on this area but would like someone to direct me what to analyse for (not myself but competent biochemists) if I would like to look at the metabolites of an alkaloid, mesembrine. If I want to see if it was taken up in animal metabolic pathways when consumed, what would I look for. or if I need to analyse for residues. Could anyone give me clues? Pstrydom Pstrydom 13:59, 19 October 2006 (UTC)pstrydom
The classification section could use a bit of cleanup. It is not clear that the examples given are not exhaustive. Also, what are the criteria for choosing specific compounds to list as examples? If it is by their importance, I would suggest adding Synephrine. With the FDA's restrictions on Ephedrine, Synephrine is becoming a popular alternative despite the fact that it may be just as dangerous. 70.100.3.62 03:20, 2 November 2006 (UTC)
If anyone has time, the {{ Alkaloids}} would really benefit from your expertise. Thanks! :) Willow 19:07, 27 January 2007 (UTC)
Currently the article opens as follows:
The wording of the first sentence seems to suggest that the "strict" definition (must be found in plants) is the most correct somehow, but the third sentence suggests that this interpretation was predated by a much broader one (any nitrogen-containing base). My feeling is that we should go by usage and not by someone's conservative interpretation of what should "strictly" be called an alkaloid. If "alkaloid" is widely used in scientific literature to describe nitrogen-containing bases that have been found in animals or fungi but not (or not yet) in plants, then I think those chemicals are alkaloids. This usage might be considered mildly controversial by some, which is worth noting, but I don't think we're justified in implying it's not "strictly" correct.
from Wiktionary:alkaloid:
The "heterocyclic" qualifier is interesting. Phenethylamine alkaloids like mescaline have only carbons in their rings, and I'd guess there are many other example non-heterocyclic alkaloids. Are there alkaloids with no rings at all? It seems like most have some type of ring structure. -- Eloil 09:51, 1 April 2007 (UTC)
An alkaloid always has some type of physiological effect on animals.
So amino acid's generally don't meet that definition. 75.15.209.116 ( talk)jimmy2000 dec 2011
Mesembrine is Alkaloid which can be added. —Preceding unsigned comment added by 196.209.60.35 ( talk) 17:36, 7 June 2008 (UTC)
I think the classification in the article needs some revising. Namely, the quaternary ammonium salts are listed as if they were part of steroids... and they aren't:) In either way they're not terpenoids so they would better fit under separate entry somewhere below. And also the Indolic alkaloids. Reserpine and yohimbine have no more relation to beta-carbolines than to simple tryptamines. They'd better be listed as a separate subgroup amongst other indoles, possibly "Yohimbans". Mytraginine has also much similarity to that particular structure. Vinca alkaloids are too indolic, so why not place them as a sub to indoles? Same about Strychnine and Ibogaine, they deserve a mention as structurally unrelated Indoles. And also, capsaicin is not an alkaloid at all, it's a vanilloid, not an amine (it's rather an amide) and thus not basic. Correct me if I'm wrong. Angsaar ( talk) 20:26, 18 July 2008 (UTC)
Fixed that, now saying it is a "steroid alkaloid", containing both a nitrogen, and a steroid skeleton as components of the structure. Linking them to "steroid" is misleading. 70.137.149.127 ( talk) 11:13, 5 August 2008 (UTC)
Regardless of the synthesis pathway, these three differ so much from the structure of the other isoquinoline alkaloids, that a separate category is justified. 70.137.149.127 ( talk) 12:26, 5 August 2008 (UTC)
I have seen the discussion about amides, leading to removal of colchicine. I think that is overzealous, piperine is an amid too, capsaicin too. 70.137.149.127 ( talk) 12:38, 5 August 2008 (UTC)
A more appropriate definition of alkaloids includes the amides. This seems to be in line with current nomenclature. Colchicine should be put back. The xanthines are also alkaloids after all. piperine and capsaicin belong in too. 70.137.180.142 ( talk) 04:59, 9 September 2008 (UTC)
See here
and here
http://www.sciencemadness.org/library/books/the_plant_alkaloids.pdf
Cacycle: your edit reverted for that reason.
70.137.180.142 ( talk) 05:25, 9 September 2008 (UTC)
I would not call the loosening of the definition arbitrary. First we would have to verify the correctness of the current definition in the alkaloid entry. I have given two book references you call sloppy. There are many more. IMO alkaloids are "nitrogen containing small molecules, naturally occuring in plants, animals and fungi, developed for defense, characterized by high physiological activity". This narrows the definition sufficiently from "natural products". In this sense the common amino acids would not be alkaloids, but "domoic acid" would be. Colchicine, piperine and capsaicin would be. The concept is a practical one, I want readers to find things where they expect them, and where they find them in scientific literature. The concept is not only a practical one but also a historical one. The line I follow here is historically founded, I don't want a new but incompatible definition, but we will do what the majority of literature does, even if it appears sloppy. After all the concept of alkaloids was introduced historically, to cover the active nitrogen containing plant substances after they were investigated, it is an ad hoc approach to nomenclature of already existing discoveries, and of a developing topic. If the books count piperine and colchicine as alkaloids, then we do too. 70.137.143.23 ( talk) 21:50, 10 September 2008 (UTC)
Please take also a look at the other ref I have given above, which is a modern teaching book, and what definition it uses. I am also not sure if the IUPHAR definition is strict and trustworthy, indeed what does "normally" mean. And are the pharmacologists competent for providing a definition, or is this a matter to be left to the researchers in the field? I will tag the current definition in the article with a fact tag. Colchicine should be in. You say:
The part "biogenetically related to basic alkaloids" means that they fall under this definition if the basic parent compound has been isolated from natural sources (preferably the same source).
This is OR.
This is for including all family members of alkaloids, even if they are quaternized or N-acetylated. I am not sure if that would include colchicine and it definitely excludes capsaicin.
This is OR too.
Furthermore: The xanthines are amides too, not very basic. The amides are basic too, only weakly. And: "mere teaching books" are good enough for inclusion as a ref. See reliable sources. 70.137.143.23 ( talk) 17:24, 11 September 2008 (UTC)
I think a historical perspective is also welcome in this century old topic; insofar a text book from the 40's would be fine. 90% of the materials is quite a bit dated, as the research of plant alkaloids has been a focus of pharmacology already 100 years ago. Think of the malaria research etc. and the research into modified opium alkaloids. I think we have to look at common and historical use to be useful in general, and not to be more catholic than the pope. 70.137.143.23 ( talk) 18:25, 11 September 2008 (UTC)
For a recent teaching book see here, it still agrees with the old refs:
http://books.google.com.br/books?id=guD67lsXymgC&printsec=frontcover&dq=Modern+Alkaloids.+Structure,+Isolation,+Synthesis+and+Biology&sig=ACfU3U2ItEZqMh72a8Xc_AZGEijQ-i-A_Q
also see the two recent articles I included as a reference. See below. I hate to bring two old book refs, (1906 and 1947), one recent book ref (brand new) and two recent peer reviewed articles, and they are all "arbitrary" and don't understand the issue, "confuse" things etc. 70.137.143.23 ( talk) 01:36, 12 September 2008 (UTC)
Acoording to this ref
http://www.pnas.org/content/103/36/13315.full
capsaicin is an alkaloid, synthesized from vanillylamine by capsaicin synthase. There you are. No OR. 70.137.143.23 ( talk) 18:40, 11 September 2008 (UTC)
Sorry, the REF SAYS THAT IT IS AN ALKALOID (literally). Thats not my funny idea. So they don't know what they are talking? 70.137.143.23 ( talk) 01:48, 12 September 2008 (UTC)
According to this review article
But see also the book sources above. (They are not hippie books, how to grow your own etc. or popular science)
Cacycle: What you are doing here is WP:Synth from the IUPHARM/IUPAC definition, which is rather mushy. (*are NORMALLY not regarded..*)
Now don't tell me all these sources are wrong: 2 teaching books, one peer reviewed primary source, one peer reviewed review article. 70.137.143.23 ( talk) 19:14, 11 September 2008 (UTC)
Further historical context:
Pictet, "The vegetable alkaloids", 1906 (and 1896)
download pdf as a google book here:
says piperine is an alkaloid, weakly basic, does not form salts with weak acids, but does form salts with concentrated mineral acids. These salts are dissociated by water. The book gives in its introduction also a history of alkaloid research and the development of the definition, from initially only pyridine compounds to what we have as of 1906. It also lists, like above book references (Not: "How to grow your own" by M.R. Hippie, The Hippiepress) Colchicine as an alkaloid. This overrides Wp:Synth from the IUPAC definition. 70.137.143.23 ( talk) 20:09, 11 September 2008 (UTC)
Certainly Pictet has not confused salt formation with hydrolysis; neither would I. Read it. 70.137.143.23 ( talk) 01:07, 12 September 2008 (UTC)
What makes you disagree with this ref
http://www.pnas.org/content/103/36/13315.full
and this ref
70.137.143.23 ( talk) 01:05, 12 September 2008 (UTC)
Thats exactly what "Pictet, The vegetable alkaloids, 1906, 1896" says. Formation of salts with strong mineral acids. Also formation of salts ("double salts") with Platinum chloride and others like that. Same for "Henry, The plant alkaloids, 1947". So we may conclude piperine is rightfully an alkaloid, historically, from its basicity, its ability to form salts. 70.137.143.23 ( talk) 15:56, 12 September 2008 (UTC)
Cacycle: look at wp amides for the weak basic character of amides. and: The chemists of the early 20th century KNEW the difference between hydrolysis and salt formation. We are not dealing with k12 students here, and we wikipedia readers usually have a GED. 70.137.143.23 ( talk) 15:56, 12 September 2008 (UTC)
I'm replying to a request for comments at Wikipedia talk:WikiProject Chemistry. All I can say is: Oh, my, this is about as productive as debating the definition of organic compound! (Something on which we have, sadly, spent too much time.) There is no unique definition and the distinction is blurry and arbitrary. You will always find some compounds that are called alkaloids by some authors and not by others. The article should reflect this reality.
One comment about the IUPAC Gold Book reference. I love the Gold Book and cite it a lot, but we should remember what it is: basically a collation of glossaries. IMHO, glossaries are meant to be useful for reference by providing a quick definition that is good enough, but should not be interpreted as "legislation". I've found some definitions in the Gold Book that I think are incomplete or deficient and, although I'm no alkaloid expert I suspect this definition may have its limitations too.
This book could be useful: Alkaloids:Nature's curse or blessing?, pages 1-5 (it's also readable on amazon.com, where I could read pages 5 and 6, which I couldn't read on Google books). The good thing about these pages is that they quote several definitions from the 19th and 20th centuries and compare them. Some focused on the plant origin, some on the basicity, some on the heterocyclic rings, but there were always exceptions. The vague definition that the author ends up proposing is "nitrogen-containing organic substances of natural origin with a greater or lesser degree of basic character". -- Itub ( talk) 09:35, 12 September 2008 (UTC)
- Returning to the question in the title of this section, capsaicin does not fall into any of the three classic types of nitrogen-bearing plant natural products, being neither a true alkaloid, a protoalkaloid, or a pseudoalkaloid. Capsaicin is of limited distribution in Nature and shows pharmacological activity, but it is non-basic, structurally unsophisticated, and not directly derived from an amino acidic precursor. On the other hand, the lack of attributes such as basicity, complexity, and an “amino acidic pedigree” can also be found in compounds commonly perceived as alkaloids. Thus, colchicine is neutral, ephedrine is structurally unsophisticated, and the nitrogen atom of the potato alkaloid solanine is not derived from an amino acid […]. For the sake of clarity and consistency, it seems therefore convenient to adopt the modern definition of alkaloids, and consider capsaicin, as well as alkylamides such as piperine and pellitorine, as such.
I have added some Literary references to alkaloids as seen in some famous novels. I thought this would broaden this interesting topic. I hope no one has a problem with it being included. Please add more to it. Proquence ( talk) 18:31, 22 November 2008 (UTC)
just raised the importance rating from mid to top.personally I don't know how anybody see this topic as mid importance!!! alkaloids are a major class in both pharmaceutical and phytochemistry that include very important drugs like morphine,quinidine and many others in a very long and ever expanding list. I am know jammed with exams so as soon as they are over I'll work on improving it-- 7amada'sback:) ( talk) 17:59, 5 January 2009 (UTC)
Morphine etc. is sometimes grouped with the benzylisoquinoline alkaloids because of its natural synthesis pathway. Morphine, codeine, thebaine, oripavine are however so different in structure from the other opium alkaloids, that they are usually grouped together as phenanthrene alkaloids. They are also pharmacologically different from the others (narcotine, papaverine...) in that they are opioid agonists, while the others are not. Looking at the structure, they are more related to each other than to narcotine etc. See entry "phenanthrene alkaloids" in the list 70.137.172.47 ( talk) 05:02, 21 September 2009 (UTC)
You will find that in pharmacological literature this distinction generally has been made, based on the high structural similarity and receptor action of morphine, codeine,thebaine, oripavine. They really make up a distinct group of substances. Your recent addition of classification and the reference supports a view where biosynthetic pathway, structural similarity and pharmacological action may be criteria in this highly complex question. Separation into the phenanthrene group would be supported by structural and pharmacological relation. 70.137.139.237 ( talk) 20:07, 22 September 2009 (UTC)
Here a recent book source stating that e.g. morphine, codeine etc. contain a hydrophenanthrene nucleus, and that "these phenanthrene alkaloids" are derived from benzylisoquinoline intermediates in the biosynthesis.
page 252. Take a look. I am not making it up. 70.137.139.237 ( talk) 21:22, 22 September 2009 (UTC)
The isoflavones with estrogenic action are a false analogy. In the phenanthrene alkaloids we have a group of opium alkaloids, which are extremely closely related in structure, synthesis pathway AND pharmacological action, but quite distinct from the other opium alkaloids in structure, synthesis pathway AND pharmacological action. The isoflavones, in contrast, have no such close structural relation to the estrogens and no common biosynthetic pathway with the estrogens. There are also synthetic opioids, which have no close relation to the phenanthrene alkaloids, sometimes also called morphinans, and there are many synthetic opioids built around the morphinan skeleton. The structure-activity relationships of morphine like alkaloids and their synthetic derivatives are very well investigated for 100 years. Alone the importance of the morphinan backbone for semisynthetic and synthetic analgetic substances justifies grouping them from the other benzylisoquinoline alkaloids.See Morphinan 70.137.139.237 ( talk) 21:40, 22 September 2009 (UTC) 70.137.139.237 ( talk) 21:40, 22 September 2009 (UTC)
To find the prevailing classification is probably beyond the scope of WP editing, as it would require a review of contemporary literature. Using an existing review would include the task, to find if this existing review came to the prevailing conclusion etc. At least the given reference is recent and it states the morphine and alike alkaloids as phenanthrene alkaloids and as derived from benzylisoquinoline by biosynthetic pathway. They are actually benzylisoquinoline alkaloids by biosynthesis, phenanthrene and morphinan alkaloids as a subgroup. The situation may be similar to the carboline alkaloids, which are also indole alkaloids. If this recent ref treats them as phenanthrene alkaloids, then I don't care if this is maybe a bit outdated. We don't need to know this better than they do. 70.137.169.140 ( talk) 22:38, 23 September 2009 (UTC)
Since when bufotenine is a poison? Tryptamines ( talk) 09:34, 29 March 2012 (UTC)
Is it necessary to have the picture of cyclopia in a sheep in this article? I'm sure I'm not the only person who doesn't like to see unexpected body horror in academic articles! Obviously, the story about the lambs receiving birth defects as a result of their mother eating the alkaloid is important - but does the picture need to be on this page? Is there some way in wiki markup to hide it, on the basis that it might be upsetting to some viewers, so you have to consciously click to see it? Baratron ( talk) 00:43, 24 June 2014 (UTC)
Hello fellow Wikipedians,
I have just added archive links to one external link on
Alkaloid. Please take a moment to review
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Cheers.— cyberbot II Talk to my owner:Online 20:28, 13 July 2015 (UTC)
I changed the solubility description. was originally:
Changed it to slightly and very slightly soluble in water (for the alkaloids, not the salts), corresponding to the Remington's table ( http://pharmlabs.unc.edu/labs/solubility/intro.htm, or http://www.sigmaaldrich.com/united-kingdom/technical-services/solubility.html):
Descriptive term | Volume (ml) of Solvent Needed to Dissolve 1g of Solute |
---|---|
Very soluble | < 1 |
Freely soluble | 1-10 |
Soluble | 10-30 |
Sparingly soluble | 30-100 |
Slightly soluble | 100-1000 |
Very slightly soluble | 1000-10,000 |
Practically insoluble or insoluble | > 10,000 |
In a medical context these substances might be considered highly soluble by some ( for example: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399483/ "Solubility is based on the highest-dose strength of an immediate release product. A drug is considered highly soluble when the highest dose strength is soluble in 250 mL or less of aqueous media over the pH range of 1 to 7.5."), but I doubt this definition is widely used (and is only useful for oral medication, you don't inject someone with 250 ml... ). Prevalence ( talk) 15:17, 22 December 2015 (UTC)
The Actions of Ergot Alkaloids in the table under the Applications heading is completely false. Whether this is by accident or ignorance, it is very misleading and may undermine the credibility of Wikipedia.
Specifically, ergot alkaloids are seldom if ever "sympathomimetic". There are no ergot alkaloids listed within the article Sympathomimetics. Second, ergot alkaloids are predominantly vasoconstricting, not vasodialating. For example, Ergotism is a disease marked by acute and chronic vasoconstriction leading to dry gangrene and vascular dementia after consumption of the alkaloids of the ergot fungus. Third, ergot alkaloids, causing vasoconstriction, are not antihypertensive. The vasoconstriction they cause increases blood pressure directly.
I'll fix it myself in a few weeks if no-one can argue why I shouldn't.
69.92.196.11 ( talk) 18:58, 16 November 2017 (UTC)
Corrected content with information found on the topic's article
Ergoline#Uses
69.92.196.11 (
talk) 15:19, 18 November 2017 (UTC)
I'm looking around for sources that would support the statement with citation [12] in the article that was marked as failed verification. This article implies that a typical alkaloid that inhibits hyperglycemia/diabetes through insulin stimulation is berberine, though that isn't mentioned among the many purported health effects that haven't been tested in humans for that chemical, and it's from J Diabetes Metab Disorder which is cited 4 times on Wikipedia in total. This article from Molecules (journal) says pretty much the same as the previous article, listing all the same alkaloids. Do either of these seem like plausible supporting evidence for the statement that alkaloids are effective against hyperglycemia or diabetes mellitus? Reconrabbit ( talk| edits) 20:25, 15 December 2023 (UTC)