Talk:Xanthine

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What about monomethyl xanthines? Surely they play some important part in the human metabolism of di- and tri- metyhlxanthines. Fuzzform (talk) 05:49, 19 November 2008 (UTC) i dont know what the hell is this —Preceding unsigned comment added by 71.129.56.208 (talk) 21:24, 29 January 2009 (UTC)

The link to CAS in the chembox shows another tautomere as Xanthine. I think the tautomere on the Common Chemistry page is better, as it shows how Xanthine relates to Caffeine for example, just by changing the substituents. --217.87.182.103 (talk) 17:52, 1 November 2010 (UTC)

Incorrect Images?

This file, correctly show a hydrogen bonded to a nitrogen at 9', but this picture, , which is on the xanthine page, shows the hydrogen at 7'. This image of xanthine also appears wrong: . Also one of the bonds is in a different location. In addition, the xanthosine image, , also correctly has a hydrogen bonded to the nitrogen at 9' prime in order to connect with the ribose. According to this site: http://www.pearsonhighered.com/mathews/ch22/xanthine.htm the xanthosine picture is correct. Does anyone else agree that both pictures on the xanthine page should be changed? Kittenono (talk) 18:03, 4 July 2011 (UTC)

It's June, 2020, and the chemical diagram still obviously does not agree with the tinkertoy pic shown. I'm a physicist, not a chemist, I don't know how to fix it. Someone please correct this obvious error.

This file, Xanthine oriented.png correctly show a hydrogen bonded to a nitrogen at 9', but this picture, Xanthin - Xanthine.svg, which is on the xanthine page, shows the hydrogen at 7'. This image of xanthine also appears wrong: Xanthine-3D-balls.png

Hello, i'm not a chemist either but i believe the two structures shown above are tautomers (see Tautomerism), meaning they can readily interconvert, therefore it is not incorrect to label both structures as xanthine, a quick google search gives this thread on stackexchange which agrees with my claim: https://biology.stackexchange.com/questions/67453/is-xanthosine-xanthine-plus-ribose I hope this clears up the confusion. — Preceding unsigned comment added by 37.237.84.9 (talk) 19:20, 5 April 2022 (UTC)

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Sorry, like saiid, i‘m no chemist: what I, and I think the medical professions, call anthines or xanthine drugs, are all purines =

“merely a second-line ...”—>“ a merely second-line ...” BTW, Don’t undo without grasping the distinction between these constructions. (I’m a chemist only to the extent that physicists who don’t get a ways beyond the intro chem courses need a better excuse than “why should I ever need to?” had better plan to work as high school physics teachers, or at least spend their careers shackled to, if not under the supervision of one or more degreed chemists. See related talk.}
—JerzyA (talk) 16:23, 25 December 2019 (UTC) & (Ex-) JerzyA, --173.162.211.85 (talk) 19:55, 13 October 2021 (UTC)

modified clinical significance

Date: Oct 20, 2020 The statement "Due to widespread effects, the therapeutic range of xanthine is narrow, making it a merely second-line asthma treatment. The therapeutic level is 10-20 micrograms/mL blood; signs of toxicity include tremor, nausea, nervousness, and tachycardia/arrhythmia" was removed. This info refers specifically to the drug theophylline which has its own page. Theophylline is not referred to as "xanthine" by people in medicine or science in any English-speaking country from my searching. If this was meant to refer generally to the trends of xanthine derivatives then such specific numbers would be irrelevant and should be cited appropriately.

I am not a botanist, but I don't think it makes sense to refer to both "holly" as well as "guayusa" and "yerba mate". Guayusa and yerba mate are Ilex guayusa and Ilex paraguariensis, respectively, and are both considered hollies. It might make more sense to say "holly (yerba mate, guayusa)" instead of listing them separately if it seems appropriate to mention that the plants are hollies. If that's the case, it omits other hollies which contain caffeine, Ilex vomitoria and Ilex tarapotina. If this is supposed to be an exhaustive table, then there are other organisms which are omitted. I think it is just more clear to remove "holly" from the table as a vast majority of the 400+ species of holly do not contain caffeine. I am doing this for theobromine in the table as well. — Preceding unsigned comment added by 2601:1C0:6E01:16D0:FD88:1276:3083:B158 (talk) 18:45, 20 October 2020 (UTC)