Talk:Xylose isomerase

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This article was the subject of an educational assignment in 2015 Q1. Further details were available on the "Education Program:University of Toronto/CHM437S Bioinorganic Chemistry (Winter 2015)" page, which is now unavailable on the wiki.

Xylose isomerase ≠ Glucose isomerase[edit]

The article claims that xylose isomerase is sometimes reffered to as glucose isomerase and "is used industrially to convert glucose to fructose in the manufacture of high-fructose corn syrup".

Please note that Glucose isomerase, the product used in corn syrup processing, is something different. The article i linked above also states clearly "Not to be confused with D-xylose isomerase." 77.6.202.122 (talk) 16:14, 10 June 2012 (UTC)[reply]

Thanks for the note. I don't understand, though: these two sources both say high-fructose corn syrup is made with D-Xylose isomerase, and both name "glucose isomerase" as a synonym. Has the process changed since those articles were published in the mid-90s? Or is "glucose isomerase" a widely used but technically incorrect colloquialism? I can't see that the other glucose isomerase, formally Glucose-6-phosphate isomerase, would be used in high-fructose corn syrup production as its substrate is phosphorylated glucose, not the glucose that is produced by glucoamylase activity. Adrian J. Hunter^{(talk•contribs)} 10:23, 11 June 2012 (UTC)[reply]

Indeed, this article is very misleading. Xylose isomerase DOES NOT CONVERT GLUCOSE TO FRUCTOSE, but does the opposite: converts fructose to glucose. It is sold to people with fructose intolerance/malabsorption to help them digest fructose and convert it to glucose. See for example this product: Xylosolv.

Here is a possible explanation for the misunderstanding: “High-fructose corn syrup (HFCS) is a mixture of glucose and fructose as monosaccharides”. So, the secret is to add the right amount of xylose isomerase to fructose to get around half of it converted to glucose, and the rest will remain as fructose: The end result is–right, you got it!–HFCS. Mazarin07 (talk) 18:07, 10 July 2016 (UTC)[reply]

D-Glucose isomerase = D-xylose isomerase[edit]

Quote from authoritative review "D-Glucose isomerase (EC 5.3.1.5, also referred to as D-xylose isomerase..." citation: DOI: 10.1021/acs.jafc.8b06293 J. Agric. Food Chem. 2018, 66, 13343−13345.--Smokefoot (talk) 13:55, 19 July 2020 (UTC)[reply]

Dietary supplement section removal[edit]

Greetings, I am relatively new to Wikipedia, yet strive to add information where I can (and it seems appropriate). I was just about to add a section here about its usage as a dietary supplement, only to find out that such a section used to exist and was removed. Jytdog, could you explain to me why this was the case? I understand there is just a single scientific study about this yet, but it claims to be double-blind and placebo-controlled, and is published in a legitimate journal - which to my (arguably amateurish) understanding means it can be used as a source. Or not? LordPeterII (talk) 11:43, 19 July 2020 (UTC)[reply]

The usual reasons content is removed for chemistry/biochem articles are:

the material is seen as specialized (primary literature vs adherance to WP:SECONDARY, WP:TERTIARY. Often folks get aggitated about soome insight/cause that they wish to communicate widely. Advocacy is always awkward in Wikipedia.
the contributing editor is promoting their own contributions (COI) or those of their pals
WP:MEDRS, often advocacy for a therapy that is insufficiently supported by citations.

If you really want a contribution to stick, write content supported by a (good) textbook citation. My two cents.--Smokefoot (talk) 12:59, 19 July 2020 (UTC)[reply]

Data: 1953 articles, reports etc discuss this enzyme, of which 78 are books and reviews (i.e., WP:SECONDARY, WP:TERTIARY). So if there are nearly 2000 papers, one has to ask, what distinguishes your paper from the many hundreds of others?--Smokefoot (talk) 13:03, 19 July 2020 (UTC)[reply]

Okay, I see. That certainly does make sense. However, I think I might have phrased it a bit wrong: My primary goal is not to include this one paper, but to add information to Wikipedia. Because this is an encyclopedia, which aims to present facts (or as close as we can get to them). And it is a fact that Xylose-Isomerase is sold as a dietary supplement. Whether it works in the advertised way is a different question altogether, and you are very right in being skeptical there, given that there is just this one primary study. Heck, there is a reason why this isn't sold as a medication, and just a "dietary supplement". But imo that makes it especially important to be discussed here, to emphasize the limited clinical support for the claims. Wikipedia has pages on official bogus even (see Pseudoscience), obviously primarily with the aim of debunking these. But yeah, removing the entire section because the scientific support for such claims is weak is counter-productive imo - the weakness should instead be prominently and unambiguously stated. LordPeterII (talk) 08:28, 20 July 2020 (UTC)[reply]

Hey, give it a try. Good luck! --Smokefoot (talk) 14:21, 20 July 2020 (UTC)[reply]

Thanks, will do. I just wanted to make sure because I'm still new and didn't want to actively go against senior editors/rules. Feel free to criticize if you think it fell short of the desired quality; I understand anything related to health needs to be given special attention on Wikipedia. --LordPeterII (talk) 10:48, 23 July 2020 (UTC)[reply]