Talk:Lichexanthone/GA1

GA Review

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Reviewer: Szmenderowiecki (talk · contribs) 14:26, 18 February 2022 (UTC)[reply]

Dear Esculenta, thank you for your detailed article, which interestingly was only created rather recently. I'd like to share my first thoughts about it before proceeding to the review itself, which is bound to take me an hour or two. Since it is my second good article review only, expect it to be directed for second review unless I am absolutely confident that this passes GA easily - I think more scrutiny over GA nominees never hurts. I admittedly can be rather weak MOS-wise, so input in this domain will be greatly appreciated.

I'd like to say that, checking through WP:GA?, I see no reasons to immediately reject the article, as it has no obvious flaws disqualifying the article, so congrats on this. Other general observations are the following:
The text is written in a rather fact-thick style, which I personally like - this is like proper encyclopedias are often written - but I have concerns about the easiness of comprehension. Sure, few people would read this article without good background in biology or chemistry, but I think making the article just a little less technical or having more cues/explanations/graphics about the chemical syntheses will certainly help. That said, this is not a major flaw and is fixable. I've also noted some minor mistakes, which I'll detail later (e.g. confusing chemical formulas with systematic names), but that's not a very large problem, either.
References generally seem to be listed and formatted properly, though I will have to make a detailed check for compliance with the relevant guideline. Sourcing also seems to be well-made and very reliable. I will look for original research in the more thorough review, but on the first glance, I see no obvious signs of it. Plagiarism check returns a negative result.
This article is thorough and uses some really good sources, and I have to commend you for making thorough queries through biological literature. This criterion seems to be easily passed, but I will look for more literature in case I believe more is needed, or if more coverage is warranted.
It is hard to be non-neutral in an article like this, and I see no issues with this one. Pass.
The article is stable, so it's an immediate check on this criterion.
There are quite enough media files, the one with the chemical formula should preferably be svg and is a public domain image by definition (chemical formulas are not original works).

More to follow by this evening (GMT time). Szmenderowiecki (talk) 14:26, 18 February 2022 (UTC)[reply]

Images

Starting from the last position, as it is usually the easiest one. I've tried to upload the relevant svg images of the structural formula, but for whatever reason MediaViewer won't display the letters in the formula, so I think the png will have to stay. The code seems to be valid, according to w3.org. See File:Lichexanthone numbers.svg and File:Lichexanthone.svg; you may overwrite them with any working version you have so long it's svg. It would be advisable to convert the png scheme to svg, too, but neither of the two things are required - they are just better.

Agree completely about changing the structural images to .svg, but I don't have the tools to do this. Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

Among other news, per WP:MOSALT images must have an alternative text for those whose browsers for whatever reason don't download images - there are none. The captions and images themselves are relevant, rationales are valid; just convert the template for the chemical formulas from CC0 to PD-chem. Any potential changes to captions will be discussed when making the text more accessible for a non-technical audience. Szmenderowiecki (talk) 21:26, 18 February 2022 (UTC)[reply]

Added alt texts, and changed license to PD-chem. Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

Text

Infobox

Please see WP:CHEMVAL and validate the reference numbers. See e.g. acetic acid for reference of how this should look like + ChEBI seems to add 9H to the IUPAC name, so it becomes 1-hydroxy-3,6-dimethoxy-8-methyl-9H-xanthen-9-one - I think this should be corrected

I added 9H to IUPAC name and listed the previous as an alternative name. I also added some verifying parameters to the chembox, but admit that's all beyond my paygrade, and I hope that some other Wikipedian that knows what they're doing will run the bot on the article! Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

Poked around a bit and think I maybe figured this out ... have now added verified id numbers. Esculenta (talk) 23:25, 27 February 2022 (UTC)[reply]

Lead (copyediting)

No need to restate what is already in the infobox, therefore, you should remove the second sentence about the naming. (Note that what you call chemical formulas are actually known in chemistry as systematic (IUPAC) names, while the chemical formulas are the ones that you write inline or the structural one which is the first image in the article).

Trimmed names from lead. Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

as well as a couple of non lichen-forming fungi - I can only see two. If you find more information on the fungi that produce the substance, I will leave it as is, but otherwise it's better to specify that there were two non-lichen-forming fungi. (non- must be hyphenated if used as an adjective, at least in British usage you seem to employ).

Changed the wording to avoid the "non-" construction. Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

[[genus|genera]] -> genera redirects to genus.
Many lichexanthone derivatives are known, some produced naturally in lichens, and others created synthetically; some of these derivatives, like lichexanthone, also have biological activities -> "like" may ambiguously suggest that it is a derivative (of itself?). In any case, either name the derivatives or rephrase the sentence.

I've reworded this bit to hopefully make it less ambiguous. Esculenta (talk) 22:36, 19 February 2022 (UTC)[reply]

The length of the lead seems pretty fine (MOS:LEADLENGTH), so for now, we leave the lead alone. Szmenderowiecki (talk) 22:30, 18 February 2022 (UTC)[reply]

Continuing.

History

a lichen that occurs in Taiwan and Japan -> wikilink Taiwan, Japan.

MOS:OVERLINK recommends to not link topics "with which most readers will be at least somewhat familiar", including countries. Esculenta (talk) 04:59, 22 February 2022 (UTC)[reply]

Notes regarding this work: Aghoramurthy, K.; Seshadri, T.R. (1953). "An improved synthesis of lichexanthone". Journal of Scientific and Industrial Research. 12B: 350–352.

1. Note that the journal is from India, at least in citations, they tend to use "(India)" at the end.

Added (India) to journal title. Esculenta (talk) 04:59, 22 February 2022 (UTC)[reply]

1. The synthesis method is not described in the History section for whatever reason, and apparently that's an improved one, compared with the original. Why the omission?

I don't have much more information other than an unnamed intermediate given in Roberts 1961. I've added a citation to show that the opinion of "simpler synthesis" and the identity of the starting reactants are sourced to him. Esculenta (talk) 04:59, 22 February 2022 (UTC)[reply]

I see. If you happen to have access to the original paper (I would doubt that's the case, but well), that would be good. Szmenderowiecki (talk) 19:19, 25 February 2022 (UTC)[reply]

The earliest syntheses of lichexanthone used orsellinic aldehyde and phloroglucinol in the "Tanase method" for synthesizing polyhydroxyxanthones. This one is way too technical. I know that Tanase method is described in an advanced chemistry textbook (Bioactive Heterocycles III, p. 152), but since there is no article for that, we should either leave out that detail, or create an article explaining the method, or visualise it (obviously, the latter two options are preferred if you have time for that). It seems to be a rather obscure reaction. I'd also leave out "polyhydroxyxanthones" detail, as it doesn't give any help about what happens in the next sentence.

Added a source that suggests that the Tanase Method is one of six standard methods for synthesizing xanthones, and the reason it's used, so perhaps it's worth keeping this bit? Although it's maybe too obscure for a stand-alone article, the six methods should be included in a synthesis section of the xanthone page, someday ... Esculenta (talk) 04:59, 22 February 2022 (UTC)[reply]

I think that unless lichexanthone is commercially produced by that method (which AFAIK isn't) or at the very least if we have a ready scheme showing the original synthesis, we shouldn't dig in so deep in the details (and even if we have the scheme, it's better to put on the scheme). We are not discussing some best-known reactions that an undergrad student learns in their chemistry course, so I think we should better leave it out, but set sights on the xanthone article instead. Szmenderowiecki (talk) 19:17, 25 February 2022 (UTC)[reply]

Merge the sentence with the "Tanase method" and the next one, as the second refers to the same compounds.
The two starting compounds, in the presence of hydrochloric acid and acetic acid, produced a fluorone derivative that was subsequently reduced to give a xanthene derivative, which, after subsequent methylation and oxidation, yielded lichexanthone methyl ether. Well, lichexanthone, as the ending of the methyl name suggests (-one), is technically a ketone, not an ether, so you can't really call it a "methyl ether". Rephrase, so that it is made clear that methylation (wikilink the term) leads to three methoxy groups, then the compound is oxidised, afterwards one of the -OCH₃ groups is demethylated to yield lichexanthone. Szmenderowiecki (talk) 16:26, 20 February 2022 (UTC)[reply]

I've reworded this part more or less according to your suggestions. How does it read now? Also, I'm considering moving the history section to the end of the article, and starting instead with the "Properties" section. Opinions? Esculenta (talk) 04:59, 22 February 2022 (UTC)[reply]

I think it's better. I will add more to the review starting from Saturday evening, as I'm now rather busy. So far I am OK with the changes; just remove the scare quotes from the Tanase method - it is recognised, it's just obscure to an average reader.

I've added a paragraph about synthesis to the parent xanthone article and directed Tanase method to there (without the quotes). Esculenta (talk) 23:24, 27 February 2022 (UTC)[reply]

Thank you, greatly appreciated. Szmenderowiecki (talk) 13:49, 11 March 2022 (UTC)[reply]

As for your question about the order: it won't matter in this particular GA review, but it seems from FA-class articles, which are the crème de la crème of all WP articles, that history section is placed at the end of the article, so I think there's some reason for that. Szmenderowiecki (talk) 19:13, 25 February 2022 (UTC)[reply]

Hello, I've been out for quite a long time (the war and that stuff), but I haven't forgotten about the review. Luckily I'm not in Ukraine, but I have some duties about it right now. I want to finish the review, possibly today, and we'll see later.

Properties

Specifically, it is a 9H-xanthen-9-one substituted by a hydroxy group at position 1, a methyl group at position 8 and methoxy groups at positions 3 and 6. "9H-xanthen-9-one" is exactly xanthone as we know it, so saying "it belongs to a class of xanthones, specifically being a xanthone..." is not really good style. It's a xanthone, substituted by groups in positions as you specified. End of story.

Sorry, I have to disagree with you here. The first sentence is about its general classification. The second gives more details, by providing the actual chemical name of xanthone and a verbal description of how lichexanthone differs. I don't see anything wrong here, but am open to alternate wordings.

Took out "a", which I think reads better? Specifically, it is 9H-xanthen-9-one substituted by... Esculenta (talk) 01:06, 14 March 2022 (UTC)[reply]

Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Its IUPAC name is 1-hydroxy-3,6-dimethoxy-8-methyl-9H-xanthen-9-one. Lichexanthone's molecular formula is C16H14O5; it has a molecular mass of 286.27 grams per mole. -> delete, it's already in the infobox.

Also disagree. In general, the infobox should be a summary of contents in the article; the compound's IUPAC name, mf and mm are basic properties that need to be included in the article (and summarised in the infobox). Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

long wavelength UV light -> hyphenate long-wavelength

Done. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

The sentence about the 2009 study does not give information of relevance of the study. We know it exists, we know the purpose of the study a- what are its results and (possibly, to the extent mentioned in the article) possible applications they outlined due to the reduction of lichexanthone? The interesting fragment I found at the end (not in the abstract) is that they were able to make a ketone out of a xanthone by breaking the middle ring, which they say is unusual. Might be relevant to report here.

I thought for quite a while about what exactly to include here and believe my summary of the study's purpose ("to characterise the reduction mechanism of lichexanthone, and to better understand the nature of its chemical reactivity.") was an appropriate level of detail for Wikipedia. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

See also I.J.C. Vieira, C.M.P. Cecchi, L. Mathias, R. Braz-Filho, E. Rodrigues-Filho, J. Braz. Chem. Soc. 9 (1998) 91. (unfortunately name not given, but if you find it, it will give some information on isolation from natural products).

Got the article, but it doesn't add anything that's not already here. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Its structure is part of the monoclinic crystal system, in the space group called P21/c. Crystallography data is best to move closer to the original sentence where you describe the pure form of lichexanthone to infobox. See also the infobox for sodium chloride, where the structure has all the data for cristalline substances (type of lattice, space group, distances, etc.) - replicate this here.

Done and done. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Biological activities

Information about fighting diseases and potential drug uses is subject to MEDRS, a strict guideline regarding biomedical claims. In vitro studies are all primary, and in fact, all of those listed here are. While I see how the first exemption of WP:MEDFAQ can apply (unlikely to be reported in high-quality secondary literature), you must make a more distanced approach to these studies, as required by MEDRS. Therefore, "it was reported", "it was suggested", "An in vitro study conducted by XYZ" and so on should best be used. We should make it clear to the reader that the studies are primary and preliminary without saying "primary"/"preliminary" outright, so that we don't have any lichexanthone runs on pharmacies who for whatever reason can't get their wife/girlfriend pregnant :) (just like we in COVID times had with ivermectin, or, in Poland, with amantadine). I hope you got my point. For citing these claims, it's best to use the original study + a short review of literature presented in other studies next to it, so that we both have the primary source and the proof that the study was recognised to be good enough to be included in the review. This concerns the whole section and it's super important to get it right. You may consider removing even some of the claims, since they are sourced to primary studies and there is no such drug so far available on the market (particularly the one about fertility).

The opening sentences of both paragraphs in this subsection already explicitly state the nature of these studies ("studied using in vitro experiments"; "In laboratory tests"). I've now doubled up the primary studies with citations to reviews that mention them (except for those where no positive results are reported). Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

This bioactivity is relevant to the field of medicinal chemistry, as there are only a few compounds known to have this effect. Leave out the first part (if you decide to retain the sperm motility claim nevertheless, though I'd consider removing it or making huge disclaimers for this).

Trimmed first bit. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Biosynthesis

Wikilink polyketide, acetate, malonate, enzyme. Otherwise no questions to this section.

Done. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Occurrence

Wikilink Parmelia, cortex.

Done. (cortex already linked as adjectival form "cortical"). Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Related compounds

62 molecules with the lichexanthone scaffold had been described -> present perfect; "scaffold" is not the term used in chemistry - just write 62 derivatives.

Tense is intentional, to go with the "As of" construction used at beginning of sentence; "scaffold" is fine in this context (in medicinal chemistry, scaffold is the core structure upon which derivatives are made as part of drug design process). Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

I've consulted a few webpages, and I'm still at a loss, though present perfect sounds more natural for me. I'll let it stand.

The last sentence must be made compliant with WP:MEDRS.

Added "According to the authors" and "in vitro". Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Eponyms

Wikilink Brazil, genera

Brazil falls into WP:OVERLINK territory, but I linked genera. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

Summary

When this is done, and the infobox values are verified with ticks, I will check the MEDRS compliance in particular and will decide if I will be fine to promote it myself or will have to refer this to another reviewer. Szmenderowiecki (talk) 14:27, 11 March 2022 (UTC)[reply]

Thanks for the suggestions and comments Szmenderowiecki. I've responded to your points above. Esculenta (talk) 22:56, 13 March 2022 (UTC)[reply]

I've made a few tweaks to the text and found that one of the svg images have been substituted to a better (working) version.

Thank you for your cooperation. I think that all policies are followed to the extent that will allow me to grant the GA status myself, and all of the concerns have been appropriately addressed. Congratulations. I will do appropriate changes to the talk page, and an icon will be displayed confirming the status of the article. You might also want to nominate this for WP:DYK. Szmenderowiecki (talk) 13:21, 15 March 2022 (UTC)[reply]