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Wiki Education Foundation-supported course assignment

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This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Hgiarami.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 06:08, 17 January 2022 (UTC)[reply]

Assessment comment

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The comment(s) below were originally left at Talk:Paraxanthine/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

It states that Paraxanthine is not found in plants - is this accurate?

I have found a paper that states that Paraxanthine has been isolated in Citrus flowers, was this later debunked?

Kretschmar J A, Baumann T W. (1999). Caffeine in Citrus Flowers. Phytochemistry, 52 (19-23).Megabunus (talk) 11:53, 20 February 2009 (UTC)[reply]

Last edited at 11:53, 20 February 2009 (UTC). Substituted at 02:16, 30 April 2016 (UTC)

A patent titled Use Of 1, 7-Dimethylxanthine for the manufacture of a non-anxiogenic psychoanaleptic drug for the treatment of a neuropsythiatric disorder states that Sinomenium acutum contains paraxanthine and cites article Isolation of lipolytic substances caffeine and 1,7-dimethylxanthine from the stem and rhizome of Sinomenium actum. --Custoo (talk) 19:41, 31 January 2018 (UTC)[reply]

I have found a textbook that says that paraxanthine is also a major metabolite of caffeine in humans; it is formed by removing a methyl group from the N3 position of caffeine.[1] Hgiarami (talk) 14:08, 1 October 2018 (UTC)[reply]

References

  1. ^ Caffeine : chemistry, analysis, function and effects. Preedy, Victor R.,, Royal Society of Chemistry (Great Britain),. Cambridge, U.K. ISBN 9781849734752. OCLC 810337257.{{cite book}}: CS1 maint: extra punctuation (link) CS1 maint: others (link)

Proposed additions

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Hi, I have been researching the existing literature on paraxanthine, and I would like to add the following to the section titled "Production and metabolism": Paraxanthine is also a major metabolite of caffeine in humans and other animals, such as mice[1]. Shortly after ingestion, caffeine is metabolized into paraxanthine by hepatic cytochrome P450[2], which removes a methyl group from the N3 position of caffeine[3]. After formation, paraxanthine can be broken down to 7-methylxanthine by demethylation of the N1 position[4], which is subsequently demethylated into xanthine or oxidized by CYP2A6 and CYP1A2 into 1,7-dimethylaric acid[5]. In another pathway, paraxanthine is broken down into 5-acetylamino-6-formylamino-3-methyluracil through N-acetyl-transferase 2, which is then broken down into 5-acetylamino-6-amino-3-methyluracil by non-enzymatic decomposition[6]. In yet another pathway, paraxanthine is metabolized CYPIA2 forming 1-methyl-xanthine, which can then be metabolized by xanthine oxidase to form 1-methyl-uric acid[7].

Following the statement that paraxanthine is not produced by plants, I would also like to add that paraxanthine is a natural metabolite of caffeine in some species of bacteria[8].

Additionally, in the introduction I believe it would be helpful to include a citation for the information explaining that paraxanthine, like coffee, is central nervous system stimulant[9].

Summary of these new additions

For this page, I think it would be beneficial to improve the production and metabolism section. For these edits, I clarified in more detail how caffeine is metabolized into paraxanthine. From this, I logically decided to explain several pathways in which paraxanthine can then be broken down further. On the current page, the production and metabolism section focused on paraxanthine in animals, but in these new edits, I included how paraxanthine is also present in humans as a metabolite of caffeine. After the pre-existing sentence that paraxanthine is not produced by plants, I also would like to add that it is a natural metabolite of caffeine in some species of bacteria. My thought process is to include my short section following the first existing paragraph in the production and metabolism section.

Hgiarami (talk) 01:47, 4 December 2018 (UTC)[reply]

References

  1. ^ Fuhr, Uwe; Doehmer, Johannes; Battula, Narayana; Wölfel, Catherine; Flick, Ingrid; Kudla, Christine; Keita, Yango; Staib, A.Horst (October 1993). "Biotransformation of methylxanthines in mammalian cell lines genetically engineered for expression of single cytochrome P450 isoforms. Allocation of metabolic pathways to isoforms and inhibitory effects of quinolones". Toxicology. 82 (1–3): 169–189. doi:10.1016/0300-483x(93)90064-y.
  2. ^ Graham, Terry E.; Rush, James W. E.; Soeren, Mary H. van (June 1994). "Caffeine and Exercise: Metabolism and Performance". Canadian Journal of Applied Physiology. 19 (2): 111–138. doi:10.1139/h94-010.
  3. ^ Mazzafera, Paulo (2004). "Catabolism of caffeine in plants and microorganisms". Frontiers in Bioscience. 9 (1–3): 1348. doi:10.2741/1339.
  4. ^ Summers, Ryan M.; Mohanty, Sujit K.; Gopishetty, Sridhar; Subramanian, Mani (May 2015). "Genetic characterization of caffeine degradation by bacteria and its potential applications". Microbial Biotechnology. 8 (3): 369–378. doi:10.1111/1751-7915.12262.
  5. ^ Mazzafera, Paulo (2004). "Catabolism of caffeine in plants and microorganisms". Frontiers in Bioscience. 9 (1–3): 1348. doi:10.2741/1339.
  6. ^ Preedy, Victor R. Caffeine : chemistry, analysis, function and effects. Cambridge, U. K.: Royal Society of Chemistry (Great Britain). ISBN 9781849734752.
  7. ^ Preedy, Victor R. Caffeine : chemistry, analysis, function and effects. Cambridge, U. K.: Royal Society of Chemistry (Great Britain). ISBN 9781849734752.
  8. ^ Mazzafera, Paulo (2004). "Catabolism of caffeine in plants and microorganisms". Frontiers in Bioscience. 9 (1–3): 1348. doi:10.2741/1339.
  9. ^ Hagedorn, Charles; Weisberg, Stephen B. (30 June 2009). "Chemical-based fecal source tracking methods: current status and guidelines for evaluation". Reviews in Environmental Science and Bio/Technology. 8 (3): 275–287. doi:10.1007/s11157-009-9162-2.