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Archive 1Archive 2

Melanin Photosynthesizing Capabilities In Humans And Animals

I have read some interesting articles on melanin is now being looked at to having photosynthesis capabilities, and may change the way we assume that plants where the only living things to use light and convert into metabolic use. They are now looking at the possibility that humans and other animals may have these photosynthesis capabilities to using melanin. The articles are not peer reviewed. The same content has been published numerous times and not once has there been a published experiment. The papers are used to sell fraudulent medicines.

References 1.The role of human photosynthesis in predictive, preventive and personalized medicine https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4125832/

2. Melanin directly converts light for vertebrate metabolic use: heuristic thoughts on birds, Icarus and dark human skin. https://www.ncbi.nlm.nih.gov/m/pubmed/18479839/ Ankhael (talk) 15:47, 12 February 2019 (UTC)

I think should be added to the article and possibly having its own page, do to the massive info i seen oh the subject. Ankhael (talk) 15:49, 12 February 2019 (UTC)

These are articles that are not peer reviewed and are from a fraudulent source. Notice that none of the referenced articles include experiments to verify these claims.

Molecular structure: infobox vs. article?

There seems to be a contradiction between the article and the infobox concerning the structure of melanin. The article says at the beginning that melanin "is a broad term for a group of natural pigments". Further down various structures are shown:eumelanin, pheomelanin, neuromelanin, etc. which all have different families of structures.

However the infobox says that melanin has a specific structure with formula C18H10N2O4. This is supported by the references to Chem Spider and PubChem (the CAS link doesn't work), so I presume that the information has some validity. However the article does not make clear why the infobox structure has the same name as the whole family of compounds. Is this a structure from which all the others are derived?? Not very obvious as the infobox structure has five fused rings which is not true for the other structures in the article. Is this the majority component of biological melanin?? If so it would be good to add a representative composition with a source. And if these two guesses are wrong, could someone please clarify the relation between the infobox melanin and the whole family of compounds? Dirac66 (talk) 21:08, 4 May 2019 (UTC)

Editing the infobox

The infobox shows a putative structure of melanin that is always, or very nearly always, incorrect. Others (see above) have noted that this leads to some confusion. The issue is summarised here: "Eumelanin from different sources is heterogeneous in size and in its fine chemical structure. Following the empirical formula (C8H3O2N) suggested by Mason [29], there are still some data on websites giving a defined stoichiometric structure [30] where melanin, ID: 4884931, is defined with the molecular formula C18H10O4N2, an average mass of 318.3 for the minimal unit, and the systematic name 3,8-dimethyl-2,7-dihydrobenzo[1,7]isoindolo[6,5,4- cd]indole-4,5,9,10-tetrone, [30] Figure 2(a). As Mason’s original proposal, these data should be considered as an empirical approximation. The natural occurrence of indole rings condensation assumed at the above tetrone model is very unlikely, although it has been sometimes proposed, as in the eumelanin pigment formed in the insect exocuticle [31]."

So, the main chemical databases also have this issue, so that unless someone really looks into it, they're going to find the wrong structure. I think that best way forward is to just remove the infobox, but I expect someone will just restore it without really looking into it. --Lucaswilkins (talk) 14:43, 13 September 2021 (UTC)

  • I have changed the chembox to a material info box. The issue being that melanin isn't really a chemical. The material infobox might not be the best plan, but I couldn't think of a better way. I've moved the chembox alongside a new section that explains the difficulties discussed here, and renamed it to 3,8-dimethyl-2,7-dihydrobenzo[1,7]isoindolo[6,5,4-

cd]indole-4,5,9,10-tetrone. Lucaswilkins (talk) 16:47, 13 September 2021 (UTC)

What is allomelanin and pyomelanin

What are they the article only says that they are nitrogen free but what are they and what is the effect of them — Preceding unsigned comment added by 64.222.180.90 (talk) 18:16, 9 May 2022 (UTC)


reference 0?

what’s up with reference 0? Anyone know how to fix? JuanTamad (talk) 09:27, 18 November 2022 (UTC)

Gingers are defective, why not just say so?

| Pheomelanin, which is produced when melanocytes are malfunctioning due to derivation of the gene to its recessive format,

Perhaps my genetics is rusty, but not only is this sentence only present to insult red-heads, but i have not the faintest clue what derivation of the gene to its recessive format could possibly mean. 68.123.8.175 (talk) 21:01, 7 January 2024 (UTC)

"Frontiers with the unknown"

The quote in the introductory paragraph is fun, whoever wrote the piece being quoted is clearly enthusiastic about the mysteries of melanin, but is it useful for a lay audience? I feel like it misrepresents the significance of melanin in a larger context. It's not as if biology suffers from a lack of unknowns besides how melanin functions. Mabolle (talk) 10:39, 18 March 2024 (UTC)

I agree, melanin is mysterious and a fruitful area for new research, no doubt, but so are several other different biomolecules I can name off the top of the top of my head… and “last remaining” frontiers? Aside from the fact that we’re nowhere near reaching the “last” frontiers of biology, when one does think of which mysteries will be the last to be solved one thinks of holy grails like cracking abiogenesis and such. 2804:14C:6590:4E59:7DDD:E23D:214B:BBE0 (talk) 02:30, 23 April 2024 (UTC)
It is a mere lyric fragment of the Nature magazine article (a quote, to say exactly), which serves as a source here. It means that melanin is not just a pigment, but it bears other functions, that we are getting to know about. They are described in the article. Probably, it should be rephrased. Tosha Langue (talk) 07:15, 23 April 2024 (UTC)

Exposure

Decreased UV exposure would result in lower melanin production, but what would happen to the existing melanin? Would it be dissolved? If a tanned person stayed out of the sun for months or years, would he become pale?

Hi I have white spots on my skin and I was wondering if eating carrots would help me get rid of these. I have gotten them befor and stayed out of the sun as much as possible and they went away and now I have gotten some more but this time they won't go away no matter how much I stay out of the sun.

If you have any ideas to help please let me know. My email address is oreo@iland.net thanks Laura

I recommend you see a doctor.-Anonymous
Wikipedia is not a medical facility, but a dictionary! -FredrikM
Wikipedia is not a place to seek medical advise, but nor is it a dictionary. Wikipedia is, believe it or not, an encyclopedia. -- Hadal 16:03, 22 Jul 2004 (UTC)

Observation

It is estimated that this color evolution in an immigrated populace takes approximately 10,000 years to complete.

If this is true, then wouldn't Native Americans that lived in northern Alaska/Canada and Tierra del Fuego have evolved lighter skin by now? To my knowledge, the Americas have been populated for about 10,000 years and for the most part, have the same skin hues. Something must be incorrect... --Bletch 22:39, 17 Oct 2004 (UTC)

Maybe it was selective breeding? :P lysdexia 00:27, 24 Nov 2004 (UTC)

Hi, not as simple as all of that. Melanin and pigments play a big role in many, many different things in the animal kingdom (see chromophores, for example, in squids, octopus, colour in birds, etc, for communication, social/sexual interactions, etc). Not only for UV protection, although it certainly does is some species. The exact mechanisms of evolution and their causes are very difficult to test and prove, particularly in human populations. Humans are highly polymorphic, and some reasons for skin colour/eye colour/"tallness" selection might be more related to sexual/sociological preferences/practices than a straightforward biological reason... On the other hand, "Evolution" implies the derivation of one species to another one, but not really an "adaptation" or "selection" of specific traits in a certain "isolated" population. It's not the same by any means...Evolution is by far more complex than that...Achaya (talk)

Melanin Theory and melanin in biotech research

See my recent additions to Black supremacy for some provocative info re the melanin as a superconductor, Melanin Theory, and also for brief references to melanin in biotech. I think all this should be included this article. I'm thinking of doing a separate article on the Melanin Theory in conjunction with (or, possibly, separate from) the Cress Theory on Color and Confrontation. People think Minstrel show is potentially explosive. It oughta be interesting to see the reactions to this on Wiki. deeceevoice 12:01, 5 Feb 2005 (UTC)

I've seen the article on "scientific illiteracy" to which the above link connects. In that particular context, I've already noted that the Melanin Theory has little credibility in mainstream thought in Black supremacy. I'll likely do something similar here -- just in greater detail. In any event, Melanin Theory certainly bears mentioning in this article on melanin -- pro and con.

I could insert more information on melanin here as a superconductor, but -- again -- I'd like someone, perhaps more familiar with the subject than I, to do so. As it stands, this article is far too limited and addresses melanin pretty much only in the context of skin pigmentation. It needs to be broadened and brought into the 21st century. Research into nanotech and plastic electronics applications has been ongoing for some time now. [In fact, I think the 2000(?) Nobel Award in science went to people involved in this kind of research.] I've already inserted information in the Superconductor article on melanin -- but only a brief blurb. Hopefully, the more technically knowledgeable will flesh that out also (no pun intended). I left one contributor to Superconductor a note soliciting input. Unfortunately, most of the major contributors to Superconductor are anonymous -- but, hopefully, someone with some expertise in the field will drop by there and here. deeceevoice 03:38, 6 Feb 2005 (UTC)

Oh, goodness! One cognitive glitch, and all these changes! Anyway, I meant to say "semiconductor" -- not "superconductor." (See talk in Black supremacy for more information. And the additions regarding melanin are actually in organic semiconductor. I still intend to do a section on Melanin Theory here and, if no one else does it, a section on melanin research and biotech applications -- one of these days. deeceevoice 12:18, 6 Feb 2005 (UTC)

List of To Do's

This list was included in the article, so I've preserved it here. If anyone is interested in expanding the piece, here are some suggested areas of interest to contributors: To be covered:

deeceevoice 19:10, 12 Feb 2005 (UTC)

Polyacetylene

There's a note that this article should include material from Polyacetylene. That article is a stub and I'm not sure how if belongs in this article. Does anyone know what needs to be merged into this article? RJFJR 02:08, Mar 10, 2005 (UTC)

Melanin is biological polyacetylene, in much the same way latex of Brazil is polyisoprene. They're two names for the same family of polymers, but one word is used by biologists and the other by materials scientists. I put the merge there (somewhat naively) thinking that materials scientists like myself should know more about the vast quantity of work that's been done on polyacetylene by biochemists. Really, the page should just become a redirect to this one...I'll try to take care of that sometime in the next week if I have the energy. Anyone interested in electronics applications should read this article.--Polyparadigm 06:30, 10 Mar 2005 (UTC)

It's clearer to me now. (The external link nicely shows the polyacetylene chain). So PolyacetyleneS is being used to refer to any molecule with a long chain of carbons with alternating single and double bonds, even if has a lot of side bonds (even ones that form rings with the back bone). The Polyacetylene chem-stub needs a diagram (prefereably, or at least a good description of what happens when you polymerize acetylene). The Melanin article might benefit from drawings of the two monomers. (Anyone have an opinion on whether this would clarify or would it just distract?) Depending how the structure is drawn the polyacetylene backbone may or may not be obvious.

Polyparadigm, I inserted a link to organic semiconductors at the bottom of the page, which I inserted a while back. I also wrote the paragraph referring to electronics applications, with a reference to "plastic electronics," a field for which there doesn't appear to be an article yet. Perhaps it exists on Wiki under another name? If not, perhaps you'd want to tackle the subject. I certainly don't know enough of the field and what's happening research-wise to do so. If there is an article on the subject, but under a slightly different name, perhaps you can insert an appropriate, working link in its stead? Thanks. deeceevoice 17:34, 11 Mar 2005 (UTC)

I'd like to refer those who have an interest in this subject to the talk page of the above-referenced article. I've brought in some additional information regarding melanin-related deafness in mammals, as well more info regarding current melanin research in the fields of quantum chemistry and plastic (or organic) electronics that should appear in this piece. And, yes. Melanin is an organic semiconductor -- a fact which has been known since 1970. deeceevoice 08:20, 18 Mar 2005 (UTC)

Unprotected

This article has been protected for too long, and in any case there is no discussion here in the past week. Unprotected. --Tony Sidaway|Talk 15:24, 27 Mar 2005 (UTC)

Restoration of disputed text

For obvious reasons, I feel user Wareware's objections to the disputed language for the section on the role of melanin in race and social bias are groundless and motivated by something other than the quality and thoroughness of this article. With User:Jiang's block removed, unless there is further and substantive objection, the relevant passages will be reinserted within a few days' time. deeceevoice 11:16, 29 Mar 2005 (UTC)

  • You asked for comment so I'll put my two cents in. Please read with many grains of salt. While melanin is the pigmentation chemical in human skin, I view this article as chemistry, material sciences and biology. But I view the material you want to add as either psychology or sociology. (Melanin molecules have neither psychology nor sociology, only humans have these). A link to other articles on human's perception of skin color, etc., is appropriate. If the material you are seeking to add already exists elsewhere in the Wikipedia then we don't need to duplicate it here but can just link to that material. This raises a related question: does that material exist in one article or is it distributed through many articles? RJFJR 02:06, Mar 31, 2005 (UTC)

Thanks for weighing in. The problem with your view, however, is that the article is about Melanin -- not the Chemistry of melanin. I don't understand why people don't get that; for me, it's a no-brainer. That's like arbitrarily saying an article titled Dog should deal with only the physical attributes of the animal and nothing else. Wikipedia is an encyclopedia, so the subjects it treats should be dealt with encyclopedically. Melanin-based color bias has been (and continues to be) one of the most important phenomena in shaping world history, in determining who are the haves and who are the have-nots: the trans-Atlantic slave trade, white supremacy and racism, segregation and discrimination in American society, India's caste system, rampant color-based bias in Latin America, colonialism, imperialism, etc., etc., etc.

This may not have anything to do with your reaction to the inclusion of such a brief discussion of the matter in this article, but I have to ask: what is it with white folks and racism -- particularly these folks on Wikipedia? Are they afraid of the issue? Is this a means of censoring subject matter and keeping articles confined to only those matters with which certain people are comfortable? I think a major dose of intellectual honesty is in order here.

If you read the disputed text, it is barely an outline of examples of such bias in human societies. It is a way of mentioning related topics in their appropriate context and an intelligent way of guiding readers to these related subjects (rather than via a rather meaningless, "see also list") without going into detail about any of them. I have to say I think your objection is completely wrong-headed and based on an unjustifiably narrow interpretation of what the scope of this article should be. deeceevoice 06:27, 31 Mar 2005 (UTC)

From the beginning of the article: Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. Sounds like Chemistry of melanin to me. Most bias in society is not based just on skin color but also on history, culture, etc. Therefore these things should be discussed elsewhere.
Why do you assume that the people who disagree with you are white folks? pstudier 22:54, 2005 Mar 31 (UTC)

That, it seems to me, is a thoroughly nonsensical argument. Every article must begin somewhere -- usually with the simplest, most basic information and then on to the more complex. That's just simply the way articles generally develop. (WHAT?) If one were to examine just about any article anywhere, it begins with a general statement and then presents additional, more detailed information. (I can't believe I even have to state this.) But to assume that the scope of an article that begins with a simple, introductory fact must be limited to an explication of merely the first one or two statements is patently absurd. Again, there is no rational argument for confining an article on melanin to solely its chemical properties. Further, the article has already breached the confines of chemical properties by discussing "Melanin in human adaptation" -- without dissent. But as soon as one attempts a meaningful, though brief, examination of "Melanin and race and social bias" -- hold up! -- there's a problem. Makes no sense at all.

Something else that makes no sense? Your debatable contention that, "Most bias in society is not based just on skin color but also on history, culture, etc. Therefore these things should be discussed elsewhere." Wrong again. Bias based on things other than melanin should be discussed elsewhere. Melanin-based bias should be addressed here.

Why do I assume that the people who disagree with me are white folks? I don't. Why are you assuming I do? Further, are you assuming that I assumed RJFJR is white? Gee, why assume that? :p deeceevoice 01:33, 1 Apr 2005 (UTC)

Well, from your above comment: what is it with white folks and racism -- particularly these folks on Wikipedia? pstudier 02:34, 2005 Apr 1 (UTC)

Well, that's what assuming things will get you: wrong again. (After all, I didn't say, "... what is it with you folks...?) Actually, the racist (and he is one; I'm not gonna get into it here) I got into an edit war with about this isn't white or black; he's Asian. Is that all you've got to say about the substance of our disagreement? (Jeeze.) deeceevoice 05:02, 1 Apr 2005 (UTC) No objection of any merit, no comeback. Text is restored. deeceevoice 15:49, 16 Apr 2005 (UTC)

Melanin and Ionizing Radiation

1. See this, probably deserves some attention...

2. The statement "It absorbs harmful UV-radiation and transforms the energy into harmless amounts of heat through a process called "ultrafast internal conversion". This property enables melanin to dissipate more than 99.9% of the absorbed UV radiation as heat..." is nonsense. The fraction of absorption always depends on density and thickness. Any real material absorbs 99.9% of uv radiation if the layer is thick enough as transmission goes down exp(-d*alpha), where d is the thickness and alpha the (non zero) absorption coefficient.

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