Talk:Polyphenol

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)

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)

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)