Talk:Polyphenol/Archive 1

toxic?

If the Wikipedia entry for Phenol shows it to be rather toxic, why are Polyphenols so beneficial?

Well, in terms of organic chemistry, just because a certain substance may be toxic to humans, it doesn't necessarily mean that other substances that maybe incorporate it as one of their components will likewise have a similar toxicity. To use benzene as an example, benzene on it's own is a powerful toxin, but when it is found as part of some other synthesized molecules, such as phenylalanine, a component of the sweetener aspartame, it is not inherently toxic. Sorry about the vagueness of my response, but I am not an organic chemist by training, and as a result, am not able to conclusively answer your question. =P wongabird 23:23, 23 March 2006 (UTC)

Phenol, also known as carbolic acid, is a chemical compound. This article is about compounds which contain phenol groups. Unfree (talk) 01:52, 17 February 2008 (UTC)

Both comments are correct. The term "phenol" refers to a specific chemical compound (carbolic acid) which is toxic. However many non-lay people also use the term "phenols" interchangeably with "polyphenols", another term which is vague among chemists. Polyphenols generally refers to aromatic plant compounds and there are many, some which are beneficial, some which are toxic and others of unknown benefit.--Ian Yee (talk) 15:33, 18 May 2008 (UTC)

Polyphenols are less toxic than phenols because of their metabolism. Phenol is metabolised by cytochrome P 450 enzymes to epoxides, which are good electrophiles and alkylate DNA and other cellular structures. If more OH groups are present metabolism by P450 results in formation of quinone structures that are less good electrophiles (but they still are see the so called quercetin paradoxon). — Preceding unsigned comment added by 161.111.147.109 (talk) 14:40, 5 June 2012 (UTC)

polymer?

Polyphenols are not polymers. Why is it listed as polymer-related, and how do you get rid of it? --137.132.3.12 19:30, 13 April 2006 (UTC)

As the "poly" in "polyphenols" suggests, polyphenols typically occur as it turn appel black

polymers of multiple modified or unmodified phenol monomers, although chemical moieties other than phenol can also contribute to their polymeric nature. Yet not all phytochemicals referred to as polyphenols by scientists strictly qualify as "large" molecules, or macromolecules, as in the case of the polymers, proteins and DNA, though some do (see: tannins). Indeed, some phytochemicals referred to as polyphenols consist of a single phenolic group with only a few carbons as side-chain (e.g., cinnamic acid, caffeic acid) (see: Croft, KD. The Chemistry and Biological Effects of Flavonoids and Phenolic Acids. Ann NY Acad Sci 1998;854:435-42). In summary, some so-called polyphenols qualify as polymers, others as oligomers--"small" polymers--while others, as relatively simple molecules, hardly qualify even as oligomers. --TonySebas 00:41, 23 June 2006 (UTC)

I disagree, a phenol is an alcohol on an aromatic ring, the poly revers to more than one alcohol on the ring. Jasoninkid 02:54, 28 March 2007 (UTC)

I suspect you're confusing "alcohol" with "hydroxyl group," Jasoninkid. Attaching a hydroxyl group (-OH) to a carbon atom in benzene changes the ring into phenol, which is by definition an alcohol (the "-ol" suffix gives it away). So phenol groups aren't on rings, they are themselves rings. Unfree (talk) 02:11, 17 February 2008 (UTC)

I agree with TonySebas. "Polyphenols" refers to aromatic plant compounds other than phenol. "Polymers" are repeating units (monomers) or types of chemical units. Many compounds referred to as polyphenols are not polymers because they don't repeat as in DNA polymers or cellulose. --Ian Yee (talk) 16:06, 18 May 2008 (UTC)

Tannins

Aren't condensed tannins phenylpropanoids? Why are they listed as separate group in the introduction? --Kupirijo 04:17, 9 February 2007 (UTC)

The history of the terminolgy has led to a deeply unsatisfying result. Condensed tannins are derived from phenlypropanoids (flavonoids, in this case) and so the venn diagram of what is a tannin and what is a phenylpropanoid overlaps. I have not come up with a good way to write this. MatthewEHarbowy 18:24, 12 February 2007 (UTC)

Tannins can bind with and precipitate protein (which allows for tanning leather) and the others don't. Jasoninkid 23:08, 31 May 2007 (UTC)

False implication that "nonheme iron" means "iron derived from plants"

"Polyphenols bind with nonheme iron (e.g. from plant sources) in vitro in model systems. [4] This may decrease its absorption by the body."

This statement needs revision. Besides the false implication, "model systems" is confusing; the source refers to "model food systems." Unfree (talk) 01:40, 17 February 2008 (UTC)

Organic produce

"A study completed in 2002 reported higher polyphenol levels in organic peaches and pears when compared to their conventional counterparts (6), and in 2003, researchers found higher polyphenol levels in organic marionberries, strawberries, and corn in comparison to conventional products (7). (reference in article - Nutrition Perspectives Vol 30, No. 3 May/June 2005)

WP article presents these studies with "Polyphenols have also been investigated as a source of additional health benefit in organic produce, but no conclusion was made."

I suggest that; (a) the presence of increased polyphenols in organic produce be acknowledged, as per the reference cited, and (b) the "no conclusion" sentence be altered to specifically reflect the studies statements "As with previous investigations, the results of these recent studies have failed to provide conclusive evidence that consumption of organic produce has a positive affect on the nutritional status of an individual. Research in this field is far from being complete and advances in scientific methods may help to provide concrete answers regarding the nutritional content of organic versus conventional produce." 124.169.170.112 (talk) 23:50, 3 October 2008 (UTC)

Quercetin

Moved from the main article. Materialscientist (talk) 23:39, 1 February 2011 (UTC)

Author note:

The titling of this section needs to be discussed at the level of a wikipedia administrator/bureaucrat, because it and its graphical and text content mistakenly and thoroughly ambiguate plant-derived "simple" phenols of all sorts with the truly higher molecular weight, more complex polyphenols. Polyphenols are true to their name in having "many" (e.g., 12-16) phenolic substructures -- as opposed to the 1-4 phenolic substructures currently displayed on this page (range 1-4, median = mean = 2.5). See, for instance, S. Quideau et al, 2011.

Hence, quercetin (deleted from the head of this page) is not by any measure a typical polyphenol, nor are phenol, hydroquinone, or other simple structures currently pictured in this article (see below). In confusing these matters, the current article distorts the relationship between structure and biological function; all chemicals presenting a phenolic group are not polyphenols, and certainly do not afford the health benefits associated with, for instance, tea and wine polyphenol components. Phenol itself caustic to external exposure, and quite toxic if taken internally. As structural complexity increases as one proceeds from phenol, to simpler di-,tri- and oligophenols, through to polyphenols, one engages with industrial dyes, toxins, plant pigments, drugs, and an array of other functional classes, in addition to medically interesting and beneficial simple, oligo-, and poly-phenols.

The fact that the web literatures on nutriceuticals propagate the ambiguities to an extraordinary degree, and that less chemically informed or less rigorous scientific venues also fail to make structure-activity distinctions -- these underlie but do not excuse the confusion that the current page now propagates. Hence, the subject of this article needs to be reviewed alongside these two other other pages -- ("phenols" and "phenol" -- and structural distinctions that underlie functional differences vis-a-vis in health, nutrition, and medicine need to be made, so that readers can draw appropriate practical information and understanding. — Preceding unsigned comment added by Meduban (talk • contribs)

References

recent major changes

I made recent major changes unaware of preceding talk. I hope some of the changes address matters relating to polyphenols as polymers, etc.

Beyond that, even after revising the head of this article, I propose it still needs further major revision. Specifically:

+ Matters pertaining more generally to plant phenolic phytochemicals, rather than to the more specific polyphenol phytochemical structural grouping, should be moved to more general articles. If polyphenols are built up of various smaller phenolic components, those components can and should be more fully discussed elsewhere -- just as there is an "amino acids" article, and a "proteins" article.

PP biosynthesis ought to cross-reference, rather than fully lay out, how these polyphenolic component parts are made -- gallic acid from phenylpropanoid pathway, etc., leaving full treatment for a specific article on phenolic biosynthesis pathways. Likewise, properties and reactivity ought to focus on what is specific to polyphenols, leaving the basics of phenol properties and chemistry to the more general phenol chemistry and plant phytochemical articles.

This suggestion includes the tables, which are far too broad in general phenolic content, rather than polyphenol content. By my count, the "carbon count table" of phenolics has only a single line, maybe two, that are relevant to polyphenols; the rest should appear in a general phytochemical phenolic article.

+ The distinction made between polyphenols and other classes of plant phenolics -- the attempt to diambiguate polyphenols from phenol dimers such as the lignans and flavanoids -- needs to be extended through the article. It now ceases at the beginning of the chemical properties section (creating internal inconsistency). Uses/appearances of "lignan", "lignin", etc., and the (limited / distinct) relationship of these to polyphenols needs to be made consistent and clear.

+ The attempt to be encyclopedic needs to be reviewed, with a paring down perhaps consistent with the content outline appearing in the recent, cited Angewandte Chemie article. The wiki article certainly needs to be **less inclusive** -- most articles from obscure research journals do **not** need to be covered, because they do not constitute accepted state of the art or practice. A rule of thumb might be to pass over articles that are not in high impact journals, and/or that have not been cited ten times over two years since publication (ggogle tracks this!), and/or if it is not from a research group with broad history of work in the area. (E.g., the French polyphenol group is one that meets the "broad history" criterion, and so its articles would be consulted as they appear.)

It is not that newer or lessor labs will fail to make important discoveries; some will, but when they do, they will be cited broadly by others. **Articles in obscure journals and from obscure research groups that are not being frequently cited do not warrant coverage in important secondary science literature (like encyclopedias).** By diluting the high impact science with too many stray reported observations, the real **emphases and priorities** of the literature of polyphenols is lost.

+ Finally, once topics and citations are pared down, the whole article needs to copy edited. At present, various tenses and other grammatical elements do not agree.

I would note that the opening sections on diambiguation / definition are currently too long. If there is a good chemistry editor out there, I would invite editing. But we should not return to the confusing confounding of the term polyphenol with all its various competing dictionary uses, which extract all substantial meaning from the best literature definition -- that polyphenol implies higher molecular weigh, soluble, literal "polyphenolic" structures.

Meduban (talk) 10:36, 11 February 2011 (UTC)

General comment and readings regarding quality of citations

For those editing this and related sections, it's important to take note: Trolling for citations with matching keywords, and other rapid methods at identifying possible citations for concepts or ideas, is fraught with scholarly danger.

First, citing an article **without having read enough of it to assure oneself that the content actually substantially addresses and supports the new text is generally considered to be a form of scholarly and academic sloppiness or dishonesty**. For a case where a pattern of such misuse of sourcing led to the firing of a U. Colorado faculty member, see Report of the Investigative Committee of the Standing Committee on Research Misconduct at the University of Colorado at Boulder, 2006 (1). More generally, and basically, on this subject, see Harvard College Writing Program, 2011 (2). Bottom line: If you do not fully understand a technical subject area, and for that reason haven't access to a practitioner's knowledge of an area, it is most often better to leave a wiki sentence or section without citation—with note that it needs citation, leaving it for another—than to assume or guess that a citation is appropriate based on a limited evaluation. **One must read and understand, before citing.**

Second, in rapidly moving scholarly areas—generally, but especially scientific subspecialties (e.g., nanotechnology, biomedicine, etc.)—all journals "are not created equal", and therefore should not be given equal credence in evaluating material for citation. Bottom line: one has to pay careful to author and/or journal reputation, history, and impact. See Prof lan Fersht, 2009 (3), wiki articles on PageRank, Impact Factor, and Eigenfactor (for journal impact), and Hirsch's h-index (for investigator impact; linked to from Fersht, op. cit.). The need for attention to quality and impact is especially true with regard to newer sources from countries with rapidly growing scientific enterprises; see David Cyranoski, 2010 (4).

In conclusion, I admonish that we cite reliably based on a first hand knowledge of actual source content, and choose citations based on their representativeness of the broad state of the scholarly discourse in an area—rather than ease of location or access!

Meduban (talk) 19:48, 15 February 2011 (UTC)

(1) [1] accessed 15 February 2011.

(2) The Harvard College Writing Program, 2011, "Harvard Guide to Using Sources",[2] accessed 15 February 2011.

(3) A. Fersht, 2009, "The most influential journals: Impact Factor and Eigenfactor, Proc Natl Acad Sci U S A. 2009 (April 28), 106(17): 6883–6884. Published online 2009 April 20. doi: 10.1073/pnas.0903307106,[3] accessed 15 February 2011.

(4) D. Cyranoski, 2010, Strong medicine for China's journals. Nature News, Nature 467, 261 (2010), doi:10.1038/467261a, published online 15 September 2010,[4] accessed 15 February 2011.

Thanks for the discourse, Meduban. Agreed! Edited to enable live links.--Zefr (talk) 21:21, 15 February 2011 (UTC)

Recommend benzenediol and -triol table/image clarification.

I don't know how to do this, but the -diols should all appear first, followed by the -triols.

Also, if desiring this to be authoritative, we should look to be sure there are no other -diols and -triols that appear in the polyphenol literature. An email to the French polyphenol group would probably answer this, as would a Scifinder search for these two structure types, then refined with the polyphenol keyword. Prof D Meduban (talk) 04:08, 23 March 2011 (UTC)

Proficiency at chemdraw, and Wikimedia Commons work?

If there are individuals following this section that are proficient with ChemDraw (or similar), and with getting images into Wikimedia Commons, there are improvements to this page I can suggest, that I myself would not have time to execute. Prof D. Meduban (talk) 04:11, 23 March 2011 (UTC)

Make images larger?

If someone has these skills -- where I would learn from you, by looking at the coding after the edit is done:

The first and third images (tannin example, and phenol equilibrium) would be better if they could be made larger ... Prof. D. —Preceding unsigned comment added by Meduban (talk • contribs) 18:12, 7 May 2011 (UTC)

I have forced fixed image width hoping it is better now. There is a usual problem that graphics is rescaled depending on the personal screen/browser settings. Materialscientist (talk) 00:47, 8 May 2011 (UTC)

Extreme verbosity

Different aims of lexicography vs. chemical nomenclature in polyphenol definition (deleted)

While scholarly, the section I removed today is an example of Wikipedia esoteric verbosity which does not serve the general reader. This has been a trend in the Article over the past year or so. Let's work on making the material understandable and enjoyable for non-specialist users.--Zefr (talk) 14:37, 8 May 2011 (UTC)

Synthetic section need attention ... Prof D

See ref. 1, Quideau, for examples of synthesis that are more in keeping with the common use of the term, and so what people might expect in this section. The two cited articles differ from this, and are at best minor examples of good polyphenol synthesis. Prof D. Meduban (talk) 09:49, 30 August 2011 (UTC)

Returning verbose section, and inviting constructive (rather than dismissive) edit.

Just as the headline says. Prof D. Meduban (talk) 09:51, 30 August 2011 (UTC)

Post it here first please to allow other editors their revisions and opinions. This text pollutes the article with excessive trivia, is not useful to a general reader and should not be reposted without an extensive rewrite. I'm placing it here for comments and editorial review by others. --Zefr (talk) 12:49, 30 August 2011 (UTC)

Historically, the subsection is a rewrite of what was already in place when I began contributing to this article; I did not discard earlier contributions (e.g., the Natl Librar Med example), I reorganized and made sense of them, by introducing and explaining the lexicography-nomenclature dichotomy. The section as it stands is not how I would have written about this, de novo. But to my understanding, carte blanche removals is not how wikipedia works, and so earlier contributions were maintained.

Specifically, in terms of the dichotomy: the subsection addresses the fact, and controversy, of why a definition of polyphenols should be used in the article that is at odds with ones that appears in on-line dictionaries and/or that one might derived by skimming the multitudinous commercial and non-academic websites making use of the term. As the subsection explains, the source of the definitional discord is in the different aims of dictionaries and chemical literature/nomenclature (the explanation of which, apparently, is the pollution and trivia you reject).

As an encyclopedia, information in articles is organized according to some principle, and this subsection makes clear that the organizing principle for the article is structure-based usage, rather than web-driven, rapidly devolving uses of the concepts. Since these edits began, the article as a whole has increasingly made chemical sense out of a complicated literature filled with rabbit trails, and of a web trove of information on various polyphenols that is largely speculative or simply nonsense.

For the record: This subsection was in the article for quite some time before you culled it, and by my understanding of wikipedia practice and policy, should remain there for editing, rather than subjecting all editors and other readers to your individual caveat (see below). You must know that the timescale for change here is months and years, and so your redaction is nothing more than that, your decision to eliminate something that annoys you personally, rather than let it remain in place for normal evolution via edit.

Finally, and also for the record: I take umbrage to your repeated approach of pulling the entire subsection, rather than contributing constructively. Note, please, that before returning the section to the article, I did a significant edit, to streamline, and remove stilted prose. That is, I did not ignore your concerns. You, however, again proceeded autocratically, removing a block of text without discussion. (I see no prior questions being asked about why the section is in place, nor do I see evidence of your reviewing the history to answer the same, nor evidence of your time spent editing the section in place to address specific concerns. Moreover, the communications you have posted regarding the section are, as I think you know, simply insulting. (Words are important, and "polluted", "trivia" and "not useful" are loaded ones, and unequivocally, your opinions). This redaction approach seems lazy and arrogant, and contrary to what was driven into me when I began setting aside time to contribute to wikipedia -- that no one individual sits in judgment over the text.

In short, my challenge: If you are someone in the heirarchy of the organization that gives you such redactive authority, state as much, and indicate where we can go to challenge your decisions. Otherwise, feel free to state your opinions, try to do so constructively, avoiding loaded language, and then, please, play by the rules. Prof D.Meduban (talk) 04:10, 31 August 2011 (UTC)

To Zefr, please place this matter in arbitration.

Zefr, We cannot continue to go back and forth. Your changes are not superficial, and they are not neutral editorially.

Beginning from the first change, removing the idea of necessary flexibility in the ranges within the published polyphenol definition, to the second, introducing the cross-referenced term "flavanol" (a low molecular weight phenol) in a way that it seems it is being offered as an example of a polyphenol (in defiance of the definition just edited), to the third, removal of the explicit reactivities that make polyphenols distinct from other phenols (precipitation reactions), etc., etc. -- you simply are reintroducing inaccuracies and errors that were earlier removed.

Were you to offer good editorial assistance, maintaining the technical message, but making the article more succinct and readable, all would be very welcome -- I was the one who put in the tags asking for such edits, after I first re-drafted the opening of this section. I WANT TO SEE THE SECTION IMPROVED, BUT RESPECTFULLY, AND WITH CLEAR UNDERSTANDING OF CONTENT. However, one should not change something that one does not fully understand, and/or has not taken the time to request clarification from earlier writers, through the discussion section. (You have asked no clarification, you have just begun carte blanche changes.) You appear too impatient to get this done, and are steamrolling.

Bottom line, we do not seem to be able to move this forward productively. PLEASE, PLACE THIS MATTER IN ARBITRATION. I haven't the experience with wikipedia to do so. But I will get it there, somehow, rather than us keeping up this discourse. Prof D Meduban (talk) 23:21, 2 September 2011 (UTC)

Highlighting current article weaknesses, inviting further edits

I added tags today, to encourage further informed editing of this article.

In re: the general quality: I will try to take the whole of the article, as soon it is in a little better shape, to Stéphane Quideau at Groupe Polyphenols in France, and see if they cannot have someone in the group do a further edit. I can do/keep check on the translation. But, they are also more on the chemistry side, and so some biological input is needed.

For more immediate attention:

(1) I added a tag above the "definitions" major section. It still needs work. Specifically, if someone can identify an article, or start one, that can discuss the tension between accepting every appearance of a chemical term on the web as definitive of its correct structure and SAR class, versus adhering to good chemical nomenclature, then much of this overly long section can be moved. It might be an article on "popular chemical terminology", or might be a section under "chemical nomenclature". What do other editors advise?

The above is asked, because this current "definitions" section is a side-bar that appears here, because it appears nowhere else. If it is moved, the article as a whole will be better focused, and can be shortened considerably. **If someone can identify or start that article and give its name here in Discussion, I can do the removing and editing to tighten up this part of the polyphenol article.** (I haven't time to explore the process of starting new articles.)

(2) I added three tags above the chemical properties subsection, intended to apply to the rest of the article. The remainder of the article needs a few things.

(a) The article needs to be reviewed to see if it reflects the preponderance of scientific opinion, and references reflecting that, and not simply be a list of interesting examples found containing polyphenol in title or abstract. That is, the relevance of what is there needs to be evaluated, with a lot staying, but likely, some going.

(b) It needs to be better organized with regard to the themes and concepts that the examples reflect. We have a whole section on polyphenol antioxidants elsewhere. Which of the entries in the article here are examples of that, so that the other Wiki section can be cited? **Much of this is about biology, and so a biomedical expert/trainee should perhaps pay attention to this particular edit.**

(c) Finally, the article needs to be checked for consistency with the top part of the article. Great pains have been taken to say what are, and what are not polyphenols. What of the references in the lower half of the article are actually about polyphenols (as defined in the article)? Some material likely should stay, other related material should likely be added, but some more low to mid-MW generic phenolic content should likely depart (i.e., about phenylpropanoids and flavanoids that are not polyphenolic). Same info might go elsewhere, but not here.

I'll be glad to do more work, but someone with biological expertise, and a willingness to go beyond titles and abstracts (and generalities) needs to look at the last half of the article. I'll come back to it when it I know what can be done to improve the definitions section, and integrate a good set of biological and related descriptions, into the article as a whole. Prof D

Is this a review that misses the forest for all the trees?

The problem with this review visit focuses on all kinds of arcane chemical and terminological issues, instead of the research on polyphenols that demonstrates that they are enormously protective biological compounds with a highly pleiotropic physiologic signature. I doubt very much that people want to read this much arcane chemistry and certainly not this much hairsplitting about chemical terminology. The more important issue is how and why polyphenols are a fundamental component of the human diet and have been for tens of thousands of years, if not longer and exactly how they function as protective compounds. I don't have enough time unfortunately pitch in on this effort, but I'm cutting and pasting below a brief overview from a book chapter (which I wrote) emphasizing the enormously complex and fundamentally protective effects that these compounds have. It's troubling that this review doesn't really address any of these issues. I wish I had time to pitch in on a major rewrite of this, but this is all I can contribute.for referencing on this little snippet, see Watt, DF (2012) The biology of aging: implications for understanding the diseases of aging and healthcare in the 21st century. Contributed chapter in Textbook of Geriatric Neurology. (Eds Nair and Sabbagh). In press for 2012.

"Although conventionally regarded as antioxidants, polyphenols are an enormous class of substances (constituting perhaps as many as 6,000 distinct compounds) found in plants, principally fruits and vegetables, that have enormously pleiotropic effects on human and mammalian physiology. Some of these effects may be more biologically significant than any direct “free radical scavenging” done by a polyphenol; they include many effects on cell signaling, the regulation of growth factors and apoptosis, the regulation of cell cycling, the regulation of inflammation, the modulation of many (if not most) cellular stress pathways, an impact on multiple transcription factors (including those involved in energy homeostasis), and (consistent with their conventional designation) the management of oxidative stress (Virgili and Marino 2008). Many of these effects on aspects of cell signaling require much lower levels of polyphenol than any direct free radical scavenging in serum or tissues. Indeed, from this perspective, polyphenols look less like antioxidants and more like complex cell physiology and cell signaling modulators. However, it seems unlikely that such a designation will replace the catchy title of “antioxidant,” even in the context of increasing evidence that such a title may be fundamentally misleading. Many, if not most, of the phenotypes of aging (oxidative stress, mitochondrial dysfunction, inflammation, and declining autophagy, among others) appear to be partially modulated by various polyphenols. From this perspective, if our ancestors consumed more plants than we do, and did so over tens of thousands of years (if not longer), the relative removal of polyphenols from the human diet (in those eating minimal fruits and vegetables) would be predicted to have complex but potentially profound effects on physiology and the trajectories of aging. Conversely, those eating a rich variety of plants may be more protected against accelerated aging and the diseases of aging. Of these two predictions, the second has been better studied, and is generally supported.

Polyphenols consist of several classes of chemical substances, including nonflavonoid compounds (such as resveratrol, other stilbenes, and curcuminoids), and classic flavonoids (consisting of two large classes, anthocyanins, which are colorful and pigmented, and anthoxantins, which are colorless). Resveratrol and its first cousin, pterostilbene, are both naturally occurring phytoalexins produced by plants in response to fungal infection (phytoalexins are all “plant defense” compounds). Of the anthoxantin family, quercetin is one of the best-known and best-studied members, along with EGCG (a member of the catechins family, with catechins constituting a large group of polyphenols in tea and wine). Dietary sources for polyphenols include many foods that have been ancient components of the human diet for many hundreds and even thousands of years: fruits and their juices (typically containing both anthocyanins and anthoxantins), tea (catechins), coffee (chlorogenic, caffeic and ferulic acids), red wine (anthocyanins, resveratrol, and quercetin), vegetables (many anthoxantins and anthocyanins), some cereals, chocolate (multiple flavonoids, including catechins and proanthocyanidins), and various legumes, particularly soy (isoflavones) and peanuts.

In this context, there are multiple challenges to any emerging science that might explain the roles polyphenols could play in health maintenance and the slowing of at least some aspects of aging. First, there are many thousands of different bioflavonoids in toto, but only a handful with much in vivo research (resveratrol, curcumin, green tea extract, and quercetin are perhaps best studied). Most of the studies of polyphenols use in vitro approaches; although there are increasing numbers of in vivo studies in animal models, very few clinical studies have taken place in humans. As an additional major challenge to potential therapeutic use, virtually all bioflavonoids have relatively poor bioavailability, which may be part of their extraordinarily nontoxic biologic footprint. Most polyphenols are rapidly conjugated (typically sulfated and glucuronided), and variably metabolized, often with an uncertain biological status of their multiple metabolites. The proper study of any polyphenol in potentially slowing or preventing any disease of aging is methodologically challenging and also expensive (long time frames are needed and it is difficult to control for many other positive and negative lifestyle risk factors). With all these scientific and methodological challenges, there is little financial incentive to study polyphenols in humans in relation to the diseases of aging or aging itself, given the poor return on investment with inexpensive agents that cannot be patented. This collection of factors has generated the current situation, where one finds much promising animal-model data for multiple polyphenols in relation to a disease of aging, but a dearth of good human clinical studies. This is changing slowly, and several polyphenols are in clinical trails related to several diseases of aging. 209.6.17.71 (talk) 22:34, 3 January 2012 (UTC) DFWatt, CHA/HMS

Before reading the following further comments, I would respectfully refer Prof Watt to references 1 and 2 in the existing article. If these are accessed, my entire opinion about polyphenols is captured. Prof D Meduban (talk) 23:42, 30 January 2012 (UTC)

Further reply to Prof Watt: I very much appreciate and agree with the comments, and am thankful for the time taken to reply. Perhaps a graduate student in your group could be assigned to further carry your informed opinions into the article. I am a chemist, can and should only edit the chemical portions, and have earlier called for such a "biological intervention" (see above). Prof D Meduban (talk) 23:43, 30 January 2012 (UTC)

Apart from trying to see some of Prof Watts material included in the appropriate sections (see preceding comment), the following is for his and other editors' further consideration/discussion.

Observations. First, as noted, this article has long needed expert biological attention, both to balance the chemical attention and volume it's received, and to make clear the wellspring of biomedical interest in polyphenols that arises from the interesting biological activities that Prof Watt has mentioned. Please see the above talk section, "Highlighting current article weaknesses, inviting further edits". I'd ask that this substantial biological expansion take place in the context of the following further observations, and so in dialog with the article's chemical contributors (who seem to care a bit more that the term polyphenol means something, and that structure-activity inferences have a true structure basis).

Second, it's noteworthy that this section has in past been a much greater, even tremendous hodgepodge of information—e.g., even further long series of one sentence paragraphs—extracted from the literature, with limited helpful article organization imposed. In that period, reference and detail inclusion criterion was, apparently and simply, that the term "polyphenol" appear in the title or abstract of a web or print article, and that a claim of the article regarding polyphenols was interesting to the editor. (One has to look at the whole revision history of an article to understand the trials that has brought it into its present form.)

Hence, there was a period where (i) there were no scholarly criteria based on chemical insight/discrimination operating, and (ii) there was limited appreciation for the need of this encyclopedia article to reflect expert opinion, or at least to accurately reflect the preponderance of scientific opinion in the polyphenol literature. Critically, in that period, the term polyphenol was misapplied to everything from plastics (!; based on Japanese citations) to simple drug-like phenols with as few as one phenolic functional group (e.g., encompassing all flavanoid articles of interest, etc.). Hence, there was nothing that would clue the reader into the developing expert appreciation that there was something special about plant-derived "true" polyphenols (WBSSH definition, phenolics above a particular molecular weight and unit phenol content).

Third, this article has undergone some revision battles, in particular from those wanting to leave the article to encompass any and all phenolic publications of interest, without structure-based discrimination (trend with which I have disagreed), and from those simply disliking the space and form of the content disambiguating polyphenols from other phenolic polymers and types (trend with which I agree, but still insisting that clarity regarding SAR somehow otherwise continue within wikipedia, to avoid a re-descent into earlier chaos).

Conclusion and prospects: I am fully in favor (i) of an immediate, careful edit of all of the biological parts of the article, to beef these up as they should be, since biological expertise has been in short supply for some time in this article; and (ii) for an "ASAP" reduction in focus of the opening nomenclature arguments; these, historically, remained in to prevent reversion to the structurally indiscriminate era, where, every result for an ArOH could be included as a "polyphenol", if the term appeared in the article and caught the eye of an editor.

I would ask in particular that there be continuing conversation here, especially regarding the second of these points. One cannot lead a reader to understand when to confer beneficial or even therapeutic potential to a substance referred to as a polyphenol, if the word has no defined meaning in the hands of the editors. Reiterating: Past experience has made very clear that the term has been used relatively indiscriminately vis-a-vis actual chemical structure in the literature, and so these uses will, without continuing attention, re-appear almost as indiscriminately in this article. If that day returns, I'll cut out all of the overly long clarifying text myself, and let the whole article revert to chemical—and therefore biochemical and biomedical—meaninglessness. On my way out the editing door.

Finally, I would, as I've indicated, be interested in taking the whole article, as soon it is in a little better shape, to Stéphane Quideau at Groupe Polyphenols in France, and see if they cannot have someone in the group comment or do a further edit. I can do the Fr-En translation. But, again, they are also more on the chemistry side, and so some real biological input is still sorely needed, first, and primarily. ProfD Meduban (talk) 00:39, 31 January 2012 (UTC)

Moved from Further reading - potential references

Books

• Daayf, F. / Lattanzio, V. (eds.). Recent Advances in Polyphenol Research (Vol. 1). 2008. Wiley – Blackwell. ISBN 9781405158374
• Santos-Buelga, C. / Escribano-Bailon, M.T. / Lattanzio, V. (eds.). Recent Advances in Polyphenol Research (Vol. 2). 2010. Wiley – Blackwell. ISBN 9781405193993

Review articles

• D’Archivo, M. et al. ”Polyphenols, dietary sources and bioavailability”, Annali dell'Istituto Superiore di Sanità (2007),43(4):348-361.
• Quideau, S. et al. ”Plant Polyphenols: Chemical Properties, Biological Activities, and Synthesis”, Angewandte Chemie International Edition (2011),50(3):586-621.

--Ronz (talk) 17:50, 6 February 2012 (UTC)

Move of interesting paragraph

This paragraph was removed from the phenolic polymers vs polyphenols section, as wrongly positioned. No objection to the text, it is just not about the subject of this section. Prof D.

A phlorotannin is a type of tannin found in brown algae such as kelps and rockweeds[31] or sargassacean species[32]. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol[33] (polyphloroglucinols)[34]. Phlorotannins are further classified as fucols, phlorethols or fuhalols. — Preceding unsigned comment added by Meduban (talk • contribs) 23:20, 15 June 2012 (UTC)

Biology section copy edit tag.

I added a {{GOCEreviewed |user=Dthomsen8 |date=September 2012}} tag to this talk page, and removed the copy edit tag from the Biology section. This section has three tags, specifically {{expert-subject|date=December 2011}}, {{off-topic|date=December 2011}} and {{specific|date=December 2011}}. Until these three tags are resolved, copy editing would not be a worthwhile endeavor. When these three tags are removed, editors can renew the copy editing request if needed. --DThomsen8 (talk) 19:09, 21 September 2012 (UTC)

General comment

I mean, all these reminders, that the sections need to be expanded etc. should be removed. Other language entries for polyphenol are rather short, much more systematic and at least offer a table to compare the most important groups, of these quite diverse natural products. It is obvious that improvements and expansions are necessary. I suggest to revise everything to be more concise. We should draw from the German and French polyphenol entries, and compile a good, and comprehensive article. I will put some time into this. Constructive criticism is welcome.(24.22.2.203 (talk) 05:01, 22 October 2012 (UTC))

Comment

More intelligent comments here on the talk page than in the article itself. Many of the entries overlap with the entries for natural phenols. While it should be reserved for larger tannin structures, many of the smaller phenolics are building blocks for larger polyphenols, and it seems hard to make a differentiation. But even on the natural phenols page, compounds are discussed that don't even have a phenolic group, because they fit in with the biosynthetic pathways. Actually the synthetic part described for polyphenols is pretty good, and I don't even know why a stickler leaves in the "citation needed" comments, when indeed the quoted articles do reflect the conclusions made in the paragraph. One should soon eliminate all the comments about references, and maybe take some of the specifics out and make more general explanations about the biological and ecological role. Chemical ecologists should jump on that, but also material scientists, and green chemists. Osterluzei (talk) 06:24, 31 July 2013 (UTC)

Oster, yes, it is hard to differentiate, but absolutely necessary. As the one who rewrote the opening to this article long ago, and called attention to need for strong editing of the later bioactivity/application sections: Polyphenol nomenclature clarity remains key to meaningful reporting on the critical classes of therapeutically and industrially useful (primarily plant-derived) higher molecular weight polyaromatic, literal polyphenolic substances. The separate natural phenols page arose, in my understanding, because particular editors wished to retain a lack of distinction between strictly defined high MW polyphenols and any other putative or demonstrated isolates or substances with phenolic substructures that bore the term polyphenol in the title or abstract of the paper—that is, to not adhere to polyphenol nomenclature, but rather to bow to web- and primary literature usage trends. At that time, I argued strenuously that the difference between organic nomenclature (which imbues chemical discussion with brevity and chemical structure meaning) and dictionary, esp. web dictionary, definition (which simply tracks and helps to establish language usage, without regard to distortion of original nomenclature/meaning)—that these needed to be understood and respected, and that while differences in definition should be reported, the "line" needed to be "held" at the WBSSH and other expert definitions. (By the usage of some, the lignans I did my doctoral research on could be called polyphenols, though they clearly bear no structural relation to tannic acid, raspberry ellagitannin, etc. As such, my lignans have no utility in tanning, no anti-oxidant health effects to speak of, etc. In chemistry, function follows form, activity arises from structure.) So, yes, Oster, the science of all this is "hard" (meaning both relatively firm, and intellectually challenging). One cannot simply report from primary sources new "polyphenol" bioactivities and clinical indications without being sure that the "thing" being discussed fits nomenclature accepted for the polyphenol class. Bottom lines, not all naturally derived phenolic substances are polyphenols, not all polyphenols will prove to have health benefits. The field (esp. non-journal web-based aspects) is rife with hype, in large part because of ambiguity related to structure-activity fundamentals. In an encyclopedia, the hard work to clarify and parse simply must be done, with experts in each subspecialty being consulted as need be. LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 07:58, 18 November 2013 (UTC)

Revised

I really had to revise all the entries, but I left the meat in there. Included a few more older publications to complete the synthetic section and shortened the Quideau discussion. All "citations needed" etc. tags could be eliminated and the text is condensed enough, as this was suggested esp. in comparison with other language entries. Please correct me, in case there is something wrong, but I eliminated a lot of double talk and redundancies. (Osterluzei (talk) 01:01, 1 August 2013 (UTC))

Thank you for all your work! This article really needed it, so thank you. I think it may still be a little too technical and jargony for your average reader, but you have vastly improved it. Thanks again. Jytdog (talk) 13:51, 1 August 2013 (UTC)

Expansion welcome

Thanks Jydog. There is no real modern chemical use for polyphenols except through tannins, so any expansions on that topic are welcome. Some people misunderstand what a primary source is, and it is perfectly fine to add anything there even if it is just research. We will later collect that material and make a new section from it. The polyphenols are indeed researched for that purpose, meaning their biological role is imitated through a possible chemical use. Too bad, this interesting entry on polyphenol coatings, which I merely edited, was deleted.63.155.133.78 (talk) 01:27, 10 September 2013 (UTC)

Research added

I added some proper research about the health affects of polyphenols. I included a reference to this research. Sadly the additions were deleted by https://wiki.riteme.site/wiki/User:Alexbrn . I would be happy to discuss here. Saul "benqish" Davis 19:49, 16 November 2013 (UTC)

I was deleting your addition at the same time but User:Alexbrn beat me to it. Please read WP:MEDRS and reconsider your edit.. the content you wrote was far too strong and certain for a single clinical study. Jytdog (talk) 19:54, 16 November 2013 (UTC)

I take the point. I am not as savvy a wikiepdia editor as i might but I would suggest that a light and quick edit would be a lot more efficent and polite and would certainly result in a better outcome. My understanding of WP:MEDRS is that identified, reliable sources from reputable, scientific journals are acceptable. The source I quoted (Journal of Nutrition) is a peer-reviwed journal of international repute. Saul "benqish" Davis 20:06, 16 November 2013 (UTC)

If that is your understanding, you did not read MEDRS, nor have you read RS. All content in Wikipedia is meant to be from reliable secondary sources. Not primary sources. The source you relied on is a primary source; under MEDRS the gold standard secondary source is something on par with a Cochrane review. A single clinical study should not be used at all in Wikipedia, and that is what you have done. IF it is used at all, it should be used very cautiously, sticking very close to what the source itself says, and content should be minimal so as not to place too much weight on it. There is a world of hype around "polyphenols" which are a very broad class of compounds, some of which are very dangerous, and some of which ~may~ have positive effects. But the class is so broad as to be meaningless to make broad statements about health effects for the class as a whole.Jytdog (talk) 20:26, 16 November 2013 (UTC)

The re-adding of this source today, especially with the "however", violates a central principle of sourcing on WIkipedia, both WP:PSTS and WP:MEDRS. You cannot use a single primary study to contest a recent-enough secondary source. You cannot. I don't understand the fiery rush to include this source. If it is indeed Very Important, there will be a review soon enough that will pick it up and show its relevant importance in the field. That is one of the key reasons why we rely on secondary sources instead of primary ones, especially for health related content.Jytdog (talk) 06:02, 17 November 2013 (UTC)

The following is offered by a scientific professional, and a primary contributor to the early, non-clinical content of this article: Hear, hear to Jytdog's comments regarding "There is a world of hype around "polyphenols" ... some of which ~may~ have positive effects.", and regarding cautious, close-to-source reporting of results from primary scientific sources. However, as a practicing synthetic/medicinal chemist and contributor to chemistry articles here, I have to point out that the secondary source paradigm at wikipedia has always been held more loosely in some areas than in others. In historical articles regarding criminal subjects, newspaper reporting remains an important and widely used source stream, simply because at times it is the only reliable source of information. And who would say that the NYT Magazine (a secondary source, with its reviews) is a better, more reliable source than the NYT or WashPost front pages? As well, the matter can be obscured for other reasons: maths differs from chemistry in that the primary unit of scholarly publication in maths traditionally was the monograph, while in chemistry it was the journal article—in both cases, where it is impossible to discern at the face whether a citation is necessarily primary or secondary. (Monograph and articles could be either.) In the same way, the primary vs secondary matter has long been only loosely applied in other physical sciences, in part because in many it can take years before a secondary source report on an important primary journal-reported discovery appears. And I would note, again from first-hand experience, that in chemistry some of the most highly cited chemistry articles yet have critically important content that has only ever appeared in primary sources (given chemists overwhelming preference for research publication over review, which developed in the transformative period from the discovery of NMR to the first Nobel in chemical synthesis). Bottom line, I think the primary vs secondary has to be evaluated thoughtfully, and expert advice sought when there is controversy. Specifically, in this case: While I would not wish to shift the later sections of the article back to being a series of one-liners on polyphenol bioactivities and uses based on title reading at Pubmed, I think a short summary of a trial reported in a top-tier journal is in order, if from established investigators/institutions (with the qualification of "One study has suggested..." that Jytdog has hinted at). With regard, LeProf. — Preceding unsigned comment added by 50.179.92.36 (talk) 07:16, 18 November 2013 (UTC)

Noting very substantial early-article content changes over the past year...

...without any discussion or explanation appearing in Talk. This will lead me to review the early chemical portions of the article, and perhaps to do some reversions of edits, where text meaning has changed drastically such that meaning is lost or factual content has become inaccurate. (Of course all editing that improved readability and accuracy is applauded, in advance!) I have already made one such change to the close of the Quideau definition paragraph. Others will follow as opening content accuracy demands and time allows. LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 08:05, 18 November 2013 (UTC)

Line in opening deleted.

The text:

"They may be broadly classified as phenolic acids, flavonoids, stilbenes, and lignans."

referencing "Manach, Scalbert, Morand, et all. (2004) [sic.] was deleted because it significantly contradicts immediately following texts regarding polyphenol definition and nomenclature. Moreover, the statement is categorically and grossly misleading with regard to actual established structural classifications within polyphenols. This is likely a case where a single reference, here nutritional rather than chemical/structural, misses the preponderance of opinion on the matter (that is actually captured in article text following). In short, the lead should summarize main body text, and not introduce distinct paradigms at odds with the main body. LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 09:12, 18 November 2013 (UTC)

Corrected WBSSH definition

Polyphenol precipitation of proteins and alkaloids is part of the original definition contained in the cited source (and so generally understood by practitioners). In general, if the original citation authors (and in this case, original wikipedia editor creating the text) created elements of a definition, only one similarly expert should attempt to alter the presented elements of that definition. I did this, originally, in arranging structural elements of the definition as bullets, and the physical and chemical behaviour elements as parallel constructs in a single sentence. Deleting this sentence misrepresents the definition and source. Editors should not remove content to shorten sections without regard for the accuracy of the content and its remaining true to the cited source. LeProf. — Preceding unsigned comment added by 50.179.92.36 (talk) 09:12, 18 November 2013 (UTC)

Change to chemical reaction section, and to lead.

The reference to precipitation (a physical change) was removed as inaccurate and misleading from the section on the reactivity of polyphenols. A single short sentence was added to the lead, to point the reader to the images of polyphenols. A picture is worth a thousand words. LeProf. — Preceding unsigned comment added by 50.179.92.36 (talk) 09:27, 18 November 2013 (UTC)

Please resize (enlarge) the raspberry ellagitannin image.

This image is currently too small to be meaningful, pedagogically, for the purposes it was intended to serve in the article. Its size should make its rings and groups roughly the same size as the tannic acid (first image in article)—by enlarging this image, or in balance, enlarging this and perhaps somewhat reducing the tannic acid. A main distinction of the class and article is that polyphenols are large and moderately complex molecules (underlying attendant novel chemical and physical behaviours), and the images should reinforce rather than obscure this impression. Thank you for helping in making this change (of which I am incapable). LeProf. — Preceding unsigned comment added by 50.179.92.36 (talk) 09:34, 18 November 2013 (UTC)

Set of sentences not actually pertaining to polyphenol chemical synthesis, or to polyphenols, removed.

The following unreferenced sentences at the head of the chemical synthesis section were removed, for the reasons explained in brackets after them:

"Most polyphenols are extracted from natural sources, such as tannic acid from Quercus spp. and the glycoside rutin from Fagopyrum esculentum. [1. This unreferenced superlative-type statement (in any case) regards the *isolation* of polyphenol natural products from their biologic sources, and *not* to their chemical synthesis. It should be moved to an appropriate section, substantiated ("most"), and referenced.]

"Others have been employed as early polymers from urushiol-based monomers for coatings and lacquers." [2. This statement regards polyphenol *use*, and not chemical synthesis, and is again unreferenced; same course proposed as for preceding sentence.]

"The synthesis of natural polyphenols is experimentally interesting but economically not feasible." [sic.] [3. This unreferenced statement of opinion is indefensible, particularly preceding a paragraph that describes ventures in the US and Europe that *are* economically supporting and accomplishing actual polyphenol chemical synthesis. It is a clearly editorial statement that, if it's returned, must be clarified (infeasible with regard to what end?) and supported by citation. I would note that in this professional's opinion, this statement makes the section/article appear sophomoric, even comical, in terms of its naivete about the aims, role, and importance of endeavors in the chemical synthesis of complex natural products. Such chemical syntheses remain the *only* broadly accepted way in which complex chemical structures are "proven" (X-ray crystallography being essentially inapplicable, NMR being fraught with complexities leading to uncertainty and periodic error; google "structure proof by synthesis"), they are a motivational mainstay in the continuing development of key, new synthetic methodologies, and are the training ground of the most sought-after synthetic organic chemists (in academia, but also in the pharma industry). The individuals in academia experimentally synthesizing polyphenols are among the elite vanguard doing this *wholly feasible work*.]

"Synthetic phenolic compounds, particularly bisphenols have been employed industrially on a large scale for the production of thermoplastic polymers since the early 50's." [4. Same as comment 2. above, vis-a-vis use. The paragraph is on chemical synthesis *OF* polyphenols, not their use as starting materials for other preparations (about which the whole of the paragraph was clear, prior to these tangential additions).]

"Synthetic phenolic compounds, particularly bisphenols have been employed industrially on a large scale for the production of thermoplastic polymers since the early 50's. They were first synthesized in the mid 1930's as synthetic estrogens, and some are now suspected to be endocrine disruptors." [5. Bisphenols are a profoundly interesting and societally important chemical family. However, BY NO DEFINITION (WBSSH OR QUIDEAU) CAN BISPHENOLS BE CLASSIFIED AS POLYPHENOLS. This structure-activity obfuscation makes absurd all the article's earlier careful crafting that has gone on to *distinguish* polyphenols from other chemical classes bearing phenolic substructures. I cannot say this more clearly or pointed: This sentence is completely non-germane to the article, and needs to be moved to an article actually on this subject.]

Finally, a further statement of opinion: I am deeply disappointed that the editing that has taken place in the chemistry sections has been done either with insufficient knowledge of basic concepts in natural products and organic chemistry usage and practice, and/or with complete disregard for the expertise brought to bear in creating the earlier parent version. Edit to make more readable, more approachable, yes! Edit, altering content so that it is no longer sourced (above!), no longer accurate with respect to sources or facts already presented and cited or to standard professional chemical uses of terms and expressions (see preceding 17-18 November edits from this editor)—these are either a waste (for the someone returning the article to accuracy) or a tragedy (if the subject matter expert washes their hands, being unwilling to do the same job over). LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 10:45, 18 November 2013 (UTC)

Thanks for these helpful edits and comments! An editor who was very invested in the mythology of the beneficial effects of natural polyphenols had done a lot of infelicitous editing in this and other articles, which I cleaned up in part. Only in part, as I am not a chemist and I recognize that WP:COMPETENCE matters. Thanks very much for your close scrutiny. 11:12, 18 November 2013 (UTC)

I appreciate the positive comment. After 4 hours of work I can ill-afford, it is worth knowing that these efforts will not be immediately reverted, and that the underlying competence is sensed and appreciated. No hard feelings about the pointed, even vociferous critique, I hope. Cheers. LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 11:20, 18 November 2013 (UTC)

No hard feelings from me. Thanks again - we really need the expertise of people like you. Jytdog (talk) 11:54, 18 November 2013 (UTC)

References

Frist pass re-edit complete...

...through the chemical synthesis section. Much attention needed for chemical/biological sections that follow, which still read like compilations based on Pubmed searching, rather than cohesive presentations. Cheers. LeProf — Preceding unsigned comment added by 50.179.92.36 (talk) 17:00, 29 November 2013 (UTC)

Make it better

I was a bit astonished to see that the section structural features was dumbed down to a high school chemistry textbook. We are not taking synthetic chemistry 101. Polyphenols need to be discussed as such, from their function, biosynthesis and occurrence in the plant cell, and my changes initially aimed at dispelling the notion that everything nowadays is a polyphenol. Now, I reintroduced some of my edits and combined them with the entries of a successor. I mean to write that usually carbon, oxygen, and hydrogen are elements of a polyphenol should be mentioned in the phenol section at most. Now, I don't disagree to be so simplistic but there are plenty of other possibilities for wikipedia entries to describe that these three elements make up a phenolic unit. Thanks.(Osterluzei (talk) 07:45, 6 January 2014 (UTC))

Please see WP:NOTTEXTBOOK, and especially #7 and #8. A "high school chemistry textbook" is about right. Jytdog (talk) 14:10, 6 January 2014 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Polyphenol/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

A nutritionist should come and clarify what's right and wrong. I'm a public health student who is studying antioxidants. From a scientific standpoint, whether antioxidant properties exist is hard to tell. The evidence is available in scientific journals. 98.226.182.19 (talk) 15:18, 22 August 2008 (UTC) "This article may contain an excessive amount of intricate detail that may only interest a specific audience" Isn't this the point of an encyclopedia? — Preceding unsigned comment added by 202.82.161.2 (talk) 12:48, 20 April 2012 (UTC)

Last edited at 12:49, 20 April 2012 (UTC). Substituted at 03:12, 30 April 2016 (UTC)

New use for polyphenols: non-melting ice cream

To be placed somewhere, perhaps under chemical uses:

 Non-melting ice cream has been developed in Kanazawa, Japan, using an unspecified polyphenol derived from strawberries.

The appropriate citation may be found by putting 'Kanazawa ice cream' into your search engine. Login54321 (talk) 10:19, 28 August 2017 (UTC)

This is just news at this point, as there are no peer-reviewed studies published to support it, so it is not justified to be included until supported by a secondary source. The effect is also not likely unique just to strawberries; the same 'extract' could be obtained from any number of cheaper raw materials. WP:NOTNEWS applies. --Zefr (talk) 14:05, 28 August 2017 (UTC)

Pronunciation

The pronunciations previously shown were incorrect -- names of chemical compounds ending in -ol are not normally pronounced /-əl/ by native English speakers. In fact, the source cited, the Merriam-Webster dictionary, shows the expected US pronunciations \ ˌpä-lē-ˈfē-ˌnōl , -fi-ˈnōl \ which translate to IPA ˌpɒliˈfiːˌnoʊl, -fɪˈnoʊl. There were errors in the Merriam-Webster to IPA conversion. M-W conventions use very regular correspondences with IPA symbols. This type of error is quite common when quoting M-W, because people have trouble with the conversion. However, the same dictionary just uses \ə\ for IPA /ə/, see e.g. petrol \ˈpe-trəl\ (not \ˌōl\) = IPA /ˈpetrəl/. I have amended the entry and provided other sources: the Collins dictionary (British) and the Canadian Oxford English (both cited as sources) agree on ˌpɒliˈfiːnɒl, which is typical of and expected for British English. Viktor Laszlo (talk) 20:46, 2 December 2017 (UTC)

Are "polyphenols" polymers of phenol?

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

@Zefr: Are "polyphenols" polymers of phenol? Eric Kvaalen (talk) 19:59, 4 May 2019 (UTC)

"Polyphenolic compounds contain more than one phenolic group," and a polymer is a natural or synthetic "large molecule, or macromolecule, composed of many repeated subunits." A complex polyphenol, such as the ellagitannin shown, has numerous phenolic subgroups, but I would say it is not a true polymer, which would have regular, repeating subunits. I couldn't find a good source clearly defining or refuting whether a polyphenol is a phenol polymer. --Zefr (talk) 21:41, 4 May 2019 (UTC)

Ellagitannin with numerous phenolic subgroups

@Zefr: If a polymer is a molecule composed of many repeated subunits, and if "polyphenols" do not have that, then is there any doubt about the fact that "polyphenols" are not polymers of phenol? And a second question, what is a phenolic group? Eric Kvaalen (talk) 07:27, 5 May 2019 (UTC)

@Zefr: If you don't answer then I will reinstate my edit. Eric Kvaalen (talk) 18:34, 8 May 2019 (UTC)

This revert was made because your edit is not lede information, is an opinion, is poorly written, is unsourced, and there is no consensus to reinstate it; WP:CON. --Zefr (talk) 18:44, 8 May 2019 (UTC)

@Zefr: There are some things that chemists just know. We don't have to reference every single sentence. These compounds simply don't fit the definition! Phenol doesn't polymerize. You still don't admit that "polyphenols" are not polymers of phenol? Do I need to start a "Request for Comment" to get support for this obvious statement? Eric Kvaalen (talk) 15:38, 12 May 2019 (UTC)

"There are some things that chemists just know. We don't have to reference every single sentence." Your statement is arrogant, unencyclopedic, and violates WP:V. That is the standard, and a WP:SCIRS source is needed. You can raise the issue at WT:MED if you wish. --Zefr (talk) 16:17, 12 May 2019 (UTC)

Do we really need a reference to say that "polyphenols" are not polymers of phenol? Eric Kvaalen (talk) 14:57, 2 June 2019 (UTC)

• Nope. Somewhere I read the quote "There are some things that chemists just know." Pelirojopajaro (talk) 15:25, 2 June 2019 (UTC)
• Yes, clearly required under our most basic WP:Verfiability principles. (Summoned by bot) I'm sorry, but no matter how "obvious" (or obviously flawed) an individual editor finds a particular label to be, the phrase "I am an expert in this field, I just know it--you should rely on my judgement" holds no value as an editorial matter under our policies. First off, that argument, were it permitted, would not just be invoked by chemists, but by any self-appointed (or indeed genuine) expert in any field and the idiosyncratic comparisons of....egos as to who has the greater expertise would bring collaboration to a crawl across the project. That is just one of numerous reasons why using one's own personal knowledge or subjective determination as a basis for content is classified as WP:Original research and wholly disallowed here.

Further WP:V leaves very little question as to the burden that must be met whenever a statement has been challenged--to whit, from the lead section of that pillar policy: "All material in Wikipedia mainspace, including everything in articles, lists and captions, must be verifiable. All quotations, and any material whose verifiability has been challenged or is likely to be challenged, must include an inline citation that directly supports the material. Any material that needs a source but does not have one may be removed." And, just a few lines below, under the WP:Burden subsection: "All content must be verifiable. The burden to demonstrate verifiability lies with the editor who adds or restores material, and it is satisfied by providing an inline citation to a reliable source that directly supports the contribution." (emphasis in original). The standard is pretty clear, and while there are plenty of facts that, as a pragmatic matter do not receive support from inline citation, the fact is that once someone does challenge a claim, the onus is on the party who wants the content to remain to provide independent, reliable sourcing. The fact of the matter is, the standard here is verifiability, not truth. I sympathize with the situation here for our chemist friends/colleagues who feel so certain that their interpretation is intuitive and correct--many are the times that I have run into a similar situation creating content in the WP:MEDRS context--but this is the way that the project approaches verifying our material and resolving conflicts arising out of differing perspectives in our editorial corps. Snow ^{let's rap} 05:30, 3 June 2019 (UTC)

• Yes - Sorry Pelirojopajaro and Eric Kvaalen, this is not chemipedia. Our readers are not just chemists, but all sorts of folks. --Nessie (talk) 15:41, 3 June 2019 (UTC)

I see your point, but what Eric Kvaalen tried to add was actually helpful to the non-chemist, not the chemist. I bet there is a reference out there that could be used, but it might take weeks to find it. I personally don't find it to be worthwhile, but I think what he added was useful. Was this really the intention of WP:V? Is someone actually challenging that polyphenols are not polymers of phenol, or are they challenging us to find a reference? Those seem like two very different battles. I looked at the page 4 for an example of basic knowledge which has few references. I never found a reference for the fact that 4 is between 3 and 5 but still, it's on wikipedia. Can we just put a cn template next to it and forget about it? Pelirojopajaro (talk) 07:18, 4 June 2019 (UTC)

• Find A Source. The edit most definitely should be there considering the target audience should be normies like me, but we should find a source for it. (Perhaps place a source needed label on it?) --NikkeKatski [Elite] (talk) 15:22, 4 June 2019 (UTC)

Which my quick attempt to find one failed horribly so perhaps the easier way is to define what polyphenol is in a section and then prove that it isnt a polymer. --NikkeKatski [Elite] (talk) 15:34, 4 June 2019 (UTC)

• No. In reply to what User "Snow Rise" has said above, nobody contests the fact that "polyphenols" are not polymers of phenol. Even Zefr agrees. It's not an opinion. I see that the same issue was raised years ago — see section #polymer?. TonySebas there mentions a book, which I suppose says what Pelirojopajaro and I are saying. Eric Kvaalen (talk) 05:32, 5 June 2019 (UTC)

Unfortunately, that reference doesn't say anything useful for us. The best I have been able to find so far is this reference saying that polymerizing phenol gives you polyoxyphenylenes instead.Pelirojopajaro (talk) 07:18, 5 June 2019 (UTC)

Except our standard for inclusion on this project is WP:verifiability via WP:reliable sources, not "what do out editors personally believe?"; it seems that you've been on en.WP for a cool decade and half now, with (as far as I can tell) a positive track record--so I'll be blunt in saying that I am more than a little mystified as to how this standard (one of the most basic principles embraced by our editorial community for virtually all of that time) is not completely second nature to you by this point. Your complete confidence that a fact is correct is not sufficient to WP:verify it--whether you are a chemist, a doctor, or a baker. Your complete confidence plus that of fifty other editors would not be sufficient under our polices: you need a reliable source once the reliability of a claim has been challenged. I can't know why Zefr decided to challenge the statement here: if they did so despite, as you say, believing that it is an accurate statement, then I would presume they did so in order to make sure our encyclopedic content conforms to a high standard of verification, which is not just permitted, but indeed encouraged by our policies.

Regardless, Zefr did challenge the statement, and the onus is now on you to source it if you want it in. Once again, I sympathize with your position: anyone who contributes content to Wikipedia in STEM fields knows this issue and has had to occasionally bite down and swallow hard on accepting the (usually temporary) absence of a statement in an article that they "know" to be factually correct. But the alternative process (self-appointed guardians of articles shouting their credentials at each-other across talk pages and engaging in unending, recursive debates about the "truth") is untenable for this project. That is why we have the objective standard of verification in reliable sources: it takes our editors and their own idiosyncratic views out of the process so that disagreements about particular points have resolve-able test and further work on the article can proceed--even if it leaves every editor unhappy with the outcome on a particular issue now and again. Snow ^{let's rap} 04:28, 6 June 2019 (UTC)

^ More accurate than I can ever be with my statements albeit unfortunate. --NikkeKatski [Elite] (talk) 13:58, 6 June 2019 (UTC)

Snow Rise, I don't see why you say that Zefr challenged the statement. He even says about one particular "polyphenol" "I would say it is not a true polymer, which would have regular, repeating subunits". He seems to be just looking for statements that don't have proper references (see Talk:Tomato/Archive 2#Energy value). But as Pelirojopajaro said, there are plenty of obvious statements in Wikipedia that don't have references, and that is as it should be. In any case, we now have a reference: Pelirojopajaro has given us one that says that polymerizing phenol doesn't give polyphenols. Eric Kvaalen (talk) 10:20, 7 June 2019 (UTC)

So I edited the article and put in the sentence "Polyphenols are not actually polymers of phenol." (It's the reference that Pelirojopajaro found.) Zefr quickly reverted it. He says the reference is not accessible. That's not a reason to remove it. There's no Wikipedia policy that says every reference has to be easily accessible, or accessible on line. Eric Kvaalen (talk) 18:24, 7 June 2019 (UTC)

UPDATE: Can you quote the statement in the article and/or use Template:Rp? Also should mention that poly as a prefix usually indicates a polymer as discussed IUPAC_polymer_nomenclature#Basic_Concepts otherwise it kinda seems like a random comment. I agree with Eric about accessibility of the reference - maybe break this into a separate discussion? Also I don't think this needs to be in the lead. II | (t - c) 23:44, 7 June 2019 (UTC)

Two separate issues here: 1) Yes, you are correct: a reliable source need not be accesible to all editors: it suffices that it is accesible to some and otherwise meets our RS standards. 2) However, based on Pelirojopajaro's "the closest thing I have found" wording above, it seems that there is a disconnect between what the source says and the statement you wish to support. In other words, I'm guessing, based on the wording of Zefr's edit summary, that they reverted not just because of the lack of accessibility, but also because there has been no consensus established here that "polymerizing phenol results polyoxyphenylenes." (Pelirojopajaro's paraphrasing) is equivalent to saying "Polyphenols are not actually polymers of phenol." In other words, you are still arguably engaging in WP:original research when you introduce this statement--or at least, that is what I take Zefr's continued objection to mean; it would be helpful if they clarified this point themselves, since inaccessibility of a source to some editors is not, standing alone, sufficient objection to discount a source.

Also, as a procedural matter, it is generally considered inappropriate (if not outright WP:disruptive) to continue to edit war over the admittance of a piece of content when there is an RfC or other significant discussion exploring that particular question that is running and has not yet reached a formal consensus--so I'd advise avoiding further edits of this nature until such a consensus resolves here. I agree with ImperfectlyInformed that the best way forward here would be for you to present the exact wording from the new source (the relevant statement plus the paragraph in which it is found would probably suffice), which would allow the editors here to judge together whether it really aligns with the content you want to add without the need for original research or synthesis. Snow ^{let's rap} 00:20, 8 June 2019 (UTC)

Well, I thought that since we now have a reference then this whole discussion was moot, so I went ahead and edited the article. The reference says that polymerizing phenol gives X, not Y (that is, polyoxyphenylenes, not polyphenols). Since we know what X and Y are, it's a bit ridiculous to say that it's "research" (original or not!) to say that Y is not X. Eric Kvaalen (talk) 13:22, 8 June 2019 (UTC)

Ok, maybe this is a better reference, and I think you will all have access. "o,o'-biphenol and o,p'-biphenol were the favored products" of polymerizing phenol. I hope this will bring an end to the discussion, wikipedia has bigger problems, including the biphenol page...Pelirojopajaro (talk) 16:26, 8 June 2019 (UTC)

@Pelirojopajaro: It also requires logging in. Please just tell us what it says about polyphenols not being polymers of phenol. Eric Kvaalen (talk) 09:21, 1 July 2019 (UTC)

• Yes. Even if a statement is a fact, not an opinion, it should still be cited with a reliable source if there is any possibility of confusion or conflict, which is definitely possible since someone could be confused about polyphenol not being a polymer of phenol. Experts may know it, but for people with less knowledge of chemistry, a reference would be appropriate. William2001^(talk) 19:47, 22 June 2019 (UTC)
• Yes - This is not just a case of the sky being blue. A source is needed, because non-chemists could reasonably think otherwise. Robert McClenon (talk) 01:49, 26 June 2019 (UTC)
• No, we do not need the reference that "the sky is not green". We do not need a reference that "polygamy" is not a polymer either. In fact, we do not need this sentence at all, if we cannot readily find the ref which say so. If there is no such references, this means this is a non-issue. What we do need is a properly written section "Etymology" to explain what suffix "poly" refers to in this case: because polyphenols contain multiple phenolic thingies. And that ref is findable even by ignorant me, but I leave it for experts to find the best one. — Preceding unsigned comment added by Staszek Lem (talk • contribs) 17:11, 26 June 2019 (UTC)

@Staszek Lem: Please provide us with at least one of the references you are able to find. Eric Kvaalen (talk) 09:21, 1 July 2019 (UTC)

I stand corrected: none of the references say that polyphenols are called so because... or smth.. They just say "polyphenols are..." . By the way, I have found a more important drawback of the article. From its text one may conclude that polyphenols are a modern invention, while in fact I googled the term in the books from 19th century. In other words, the article misses "History" section. Unfortunately google was of no help: when searching 19th century texts, the early sources reported by google to contain "polyphenol" in fact contained "Polyphemus" :-) Staszek Lem (talk) 21:57, 1 July 2019 (UTC)

• Here is written "it wasn't until 1894 that the first known use of the word polyphenol according to the Internations Scientific Vocabulary. Well, this 1891 book uses the word occasionally. Staszek Lem (talk) 22:14, 1 July 2019 (UTC)
• This 1892 volume of J Chem Soc. uses the word "polyphenolic" in a review of a 1892 article (Sur l'origine des matières colorantes de la vigne; sur les acides ampélochroiques et la coloration automnale des végétaux), A. Gautier Staszek Lem (talk) 22:30, 1 July 2019 (UTC)
• this French 1885 Encyclopédie chimique uses the word " polyphénolique". Staszek Lem (talk) 22:53, 1 July 2019 (UTC)

@Smokefoot: would you care to weigh in? Pelirojopajaro (talk) 18:51, 2 July 2019 (UTC)

References

With the proviso that I am not a subject expert, one suggestion would be to use language like "Ordinarily polyphenols refer to natural products containing several phenolic functional groups." I guess one could electropolymerize phenols, but it is not a big deal (or there would be books or reviews) and Bakelite (phenol-formaldehyde) is perhaps a polyphenol to some folk but I havent heard of it referred to as a polyphenol. Here are some hits ("Showing 1 - 20 of 79 Results for polyphenols") that came up when I searched my institution's library for ebooks with "polyphenols" in the title. This list would imply that the predominant usage is in the area of natural products.

• Plant polyphenols 2 : chemistry, biology, pharmacology, ecology /Published c1999/Call Number: 572.2 P694
• Polyphenols in human health and disease /Published 2014
• Polyphenols : properties, recovery, and applications /Published 2018
• Flavonoids and other polyphenols /Published c2001
• Non-extractable Polyphenols and Carotenoids : Importance in Human Nutrition and Health by Saura-Calixto, Fulgencio Published 2018
• Advances in technologies for producing food-relevant polyphenols /by Cuevas Valenzuela, Jose Published 2017

• According to the chapter entitled "Plant Polyphenols" in Wiley Encyclopedia of Chemical Biology (doi.org/10.1002/9780470015902.a0001913.pub2): "Polyphenols are plant secondary metabolites derived from the phenylpropanoid and polyketide biosynthetic pathways that feature more than one phenolic ring in their basic chemical structure." Hoping that this info helps your discussion.--Smokefoot (talk) 22:41, 2 July 2019 (UTC)

The thing is, we all know what the term "polyphenols" is used for, and we all know that they are not polymers of phenol. The problem is that when I tried to put in a couple sentences pointing this out, it was reverted on the grounds that I didn't give a reference. Then when I gave a reference it was reverted because you have to log in in order to read the reference (which is not a legitimate reason to remove the statement). I'm going to try once again to put in a sentence, in the hopes that Zefr won't revert it again. Eric Kvaalen (talk) 07:21, 14 July 2019 (UTC)

---

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.