Talk:Caffeine/Archive 3

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Archive 2 Archive 3 Archive 4

numerical discrepancy?

"250 milligrams (more than 2-3 cups of brewed coffee" "The LD50 of caffeine is (...) estimated to be about 150 to 200 milligrams per kilogram of body mass, roughly 140 to 180 cups"

Call average body mass 70kg, to be on the low side. Say a cup contains 125mg of coffee, erring on the high side. 70/.125 = 560, significantly more than "140-180 cups". What am I missing?

The following:
  1. Your signature: 01:11, October 11, 2006
  2. A factor with value: 0.150 to 0.200 g/kg or 5 lbs
  1. The units for the value 70: kg
  2. The units for the value 0.125: g
Jclerman 09:16, 11 October 2006 (UTC)
Also, 70kg may be average for males, not for females except possibly very few parts of the world (USA).
0.175 g/kg * 70kg = 12.25g
12.25g / (0.250g / 3) /cup = 147 cups
Samsara (talkcontribs) 09:32, 11 October 2006 (UTC)


Title: Caffeine in coffee: Its removal. Why and how? Author(s): Ramalakshmi K, Raghavan B Source: CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION 39 (5): 441-456 1999 --Stone 09:15, 21 August 2006 (UTC)

  • I'm working on obtaining this and a couple of other similar articles. The problem I'm facing at the moment is that my institution does not have a subscription to any of these, so I'm going to have to pay the $28 or so each to download them. If nobody else gets a hold of them (especially the above article) in the next day or so, I'm going to buyat least one of them myself. – ClockworkSoul 15:57, 21 August 2006 (UTC)

I hav it !--Stone 07:41, 22 August 2006 (UTC)



  • Fischer, Ach. Ber. 28, 2473, 3135 (1895);--Stone 10:06, 21 August 2006 (UTC)
  • Volume 33, Number 19 / 2003 Pages: 3291 - 3297 DOI: 10.1081/SCC-120023986 A Novel Method of Caffeine Synthesis from Uracil Matthew A. Zajac , Anthony G. Zakrzewski , Mark G. Kowal , Saraswathi Narayan --Stone 10:10, 21 August 2006 (UTC)

Featured article candidacy

Just in case anybody who edits here is unaware, this article is currently being considered for featured article status. If you like, you can comment on the article's FAC page. – ClockworkSoul 20:13, 21 August 2006 (UTC)

Congrats on making FA; and I didn't even get a chance to vote yet! CS you really did amazing work on this article. Drop me a line if any other project needs copyediting. Anchoress 06:37, 5 September 2006 (UTC)
Thanks, Anchoress! It was very much a team effort, but that won't stop me from taking you up on your offer at some time in the future! – ClockworkSoul 14:50, 5 September 2006 (UTC)


I don't think this change is an improvement. Anyone else have an opinion? Anchoress 23:48, 21 August 2006 (UTC)

I changed it because the wording "it is found with" didn't really make sense to me. The key (as I understand it, from the sentence that follows) is that the plants that contain caffeine also contain other stuff, so depending on what plant you're extracting, you get different amounts of that other stuff. That's why, when fixing the wording I didn't like, I used the term "sources" as subject for an active verb instead of a passive voice. DMacks 00:35, 22 August 2006 (UTC)
I like what you guys did with it. Good work! – ClockworkSoul 03:00, 22 August 2006 (UTC)

There is a very funny story about coffee i miss on this page, in the early history of coffee in europe, when coffee got introduced, it supposedly so that so many people got addicted, they started tracing the coffee to the source, resulting in about 200000 coffee addicts moreless living along the road istanbul - venice. Why is it not in? 08:09, 16 September 2006 (UTC)

synthetic caffeine

Here is some proof that synthetic cafeine is used in beverage and pharmaceutical products:

  • Ulrich Flenker, Wilhelm Schänzer (2001). "Determination of 13C in Urinary Excreted Caffeine". European Journal of Sport Science. 1 (2). 

They do 13c with caffeine from:

  • pharmaceutical products δ13C -38
  • energy drinks δ13C -39
  • soft drink δ13C -40
  • green tea produkt δ13C -31
  • black tea produkt δ13C -29
  • coffee product δ13C -27

The value shows that the first products contain caffein produced not by plants in the last years, as there is no hundred year history of caffein storage, it has to be from carbon incorporated into the plants earlier. Oil or gas are the major sources and therefor it is artifical or snthesised caffein.-- 12:11, 31 August 2006 (UTC)

To-do list

The to-do list at the top is huge, and it seems like everything's been done. Could it be removed maybe? Anchoress 06:51, 5 September 2006 (UTC)

  • Indeed, it is time, now that the FA has finally come through. I scrubbed almost all of the contents, but if you prefer, please feel free to just remove the {{todo}} tag itself. – ClockworkSoul 14:48, 5 September 2006 (UTC)
  • Should this talk page be archived as well? Seems like a good time to clean it out. -Ravedave (help name my baby) 16:55, 5 September 2006 (UTC)
Lol I just did, if you look a couple of sections up. I doubt there's going to be too much more to talk about (until or unless Caffeine gets front paged), so I'm comfortable with leaving what's here here for now, but if you want to archive more, go ahead. Anchoress 17:28, 5 September 2006 (UTC)
Yeah actually, now that I look a lot more could be archived. I'll go do that now. Anchoress 17:29, 5 September 2006 (UTC)

I see that there's still one outstanding to-do on the list. How much more information on the subject of it's use to treat apnea of prematurity would be appropriate in the main article? dil 14:25, 7 September 2006 (UTC)

  • Not even a full paragraph, really. I think that two or three sentences should be entirely appropriate and satisfactory. – ClockworkSoul 14:38, 7 September 2006 (UTC)
    • Done. dil 19:32, 8 September 2006 (UTC)
      • Thanks, Dil! Our to-do list is now empty. – ClockworkSoul 02:28, 9 September 2006 (UTC)

Translation of Kurdish (?) title

In 1587, Malaye Jaziri compiled a work tracing the history and legal controversies of coffee, entitled "Umdat al safwa fi hill al-qahwa".

Can we get a translation of this title please? —Keenan Pepper 03:09, 9 September 2006 (UTC)

Front page Heads Up

Those of us who are watching/contributing to this article should keep a very close eye on it when the front page turnover happens. For many of us this will be the afternoon/evening of the 15th. Typically, front page features are vandalism magnets, and they often have 100+ edits (mostly good faith of course) during the 24 hours of FP feature status. Anchoress 17:52, 12 September 2006 (UTC)


The article currently reads:

Its name is derived from the Italian caffè ("coffee") plus the alkaloid suffix -ine.

Is there any reason to think it comes directly from Italian, and not, say, the Neo-Latin caffeum? Given that scientists still frequently wrote in Latin until the 1800s or so, it would not be surprising for such a root to be well known. And Italian caff-, French caf-, and German Kaff- would all be expected results from a Latin caff-, whether or not they actually derived from it. In other words, just because the Italian orthography is closest, does not necessarily mean this word came directly from Italian. So do we have further evidence? [To be fair, I should mention that the word is variously spelled in Neo-Latin, though today caffeum seems the most common.] --Iustinus 00:56, 16 September 2006 (UTC)

From the M-W Dictionary online:
Main Entry: caf·feine; Pronunciation: ka-'fEn, 'ka-" ; Function: noun;
  • Etymology: German Kaffein, from Kaffee coffee, from French café
  • a bitter alkaloid C8H10N4O2 found especially in coffee, tea, cacao, and kola nuts and used medicinally as a stimulant and diuretic.
If Runge published in German in 1819 and he or Goethe named the substance, German might be the origin.
Jclerman 01:08, 16 September 2006 (UTC)
That would seem to dissagree with the article then. My preference would be just to say it was from "the root caffe- (meaning coffee)", without actually specifying languages of origin: since scientific words are supposed to be international anyway, does it really matter which language was the proximal source of the word caffeine? --Iustinus 01:11, 16 September 2006 (UTC)
If Runge published in German in 1819 and he or Goethe named the substance, German might be the origin. Give credit to the discoverer. It would be wise to cross-check with the OED. Jclerman 01:15, 16 September 2006 (UTC)
It just seems to me that worrying about whether the source is the German word for coffee, or the Italian one is pointless: we certainly don't worry which language was the first to coin words like archosaur, or cnidarian, or ribosome, so why should we worry about this? On the other hand, tracking down the earliest usages of the word might be fun. Unfortunately, the OED is not terribly helpful (I had already checked it before asking here):
[ad. F. caféine, f. café coffee + -INE; see prec.]
A vegetable alkaloid crystallizing in white silky needles, found in the leaves and seeds of the coffee and tea plants, the leaves of guarana, maté, etc.
1830 LINDLEY Nat. Syst. Bot. 206 Coffee is..supposed to owe its characters to a peculiar chemical principle called Caffein. 1863 WATTS Dict. Chem. I. 707 Caffeine was discovered in coffee by Runge in the year 1820. Oudry, in 1827, found in tea a crystalline substance which he called theine, supposing it to be a distinct compound; but Jobat showed that it was identical with caffeine. 1869 Daily News 22 July, A piece of kaffeine, of the size of a breakfast plate, produced from 120 pounds of coffee.
So the OED actually seems to attribute this word to French, though the 1869 quote, spelled with k, implies a German origin. But as I said above, it doesn't seem necessary to worry about that specifically. Unfortunately, the OED rarely provides non-English citations, so we can't trace it back farther than 1830 by that means. --Iustinus 02:38, 16 September 2006 (UTC)

I commented out the sentance, we should reach consensus before re-adding it. Also we apparently have conflicting sources so the uncertain nature should be added if that is the case. Lets compile a list. -Ravedave (help name my baby) 04:53, 17 September 2006 (UTC)

List of sources for etmology:


Does anyone think it's worth mentioning Honoré de Balzac in terms of caffeine addiction? I'm pretty sure over-consumption of coffee hastened his death.

Here's a link: [1] O'Hara 01:33, 16 September 2006 (UTC)

  • That article seems to want to make an implication that caffeine caused his death, but it doesn't directly state it. I doubt if there's any solid evidence that caffeine hastened his death. Tnek46 03:33, 10 October 2006 (UTC)


Is theine an isomer of cafiene or is it exactly the same thing? I heard on jeopardy that it was.whicky1978 talk 04:11, 16 September 2006 (UTC)

exactly the same thing Jclerman 05:18, 16 September 2006 (UTC)


Every time I click on the caffeine page, I swear it has vandalism on it. Couldn't the article have minor protection until it's off the main page. It's a bit of an annoyance to see, and I quote:

[quote removed] -User talk:

What if an African-American was doing an essay or something on caffeine, and saw that. That'd be racist. Couldn't some kind of protection be placed on the page just temorarily? --andrewI20Talk 06:21, 16 September 2006 (UTC)

Well, it'd still be racist even if nobody saw it ;-) --Grey Knight 06:35, 16 September 2006 (UTC)
Sorry no, it's very unusual for front page FAs to be protected. Anchoress 06:36, 16 September 2006 (UTC)
A more long term solution is being considered, where rogue edits don't appear to casual readers. Stephen B Streater 08:56, 16 September 2006 (UTC)

I'm pretty sure this page has been vandalised with the photograph that supposedly shows a spiders web when affected by caffine - seems awfully similar to which is a well known spoof.

Evolutionary convergence?

It seems to me that the presence of caffeine in diverse plants is an example of convergence: it evolved separately as an insecticide in diverse plants, rather than evolving once in a common ancestor. Is that the case? Dynzmoar 12:33, 16 September 2006 (UTC)

It's an interesting idea. Do you think you could do the research? Best, Samsara (talkcontribs) 15:26, 16 September 2006 (UTC)

Unsourced statement

There is one: "It is speculated that this reduction in bronchopulmonary dysplasia is tied to a reduction in exposure to positive airway pressure".

--Brand спойт 12:51, 16 September 2006 (UTC)

Structure images

I didn't like the 3D structure on this page, because it doesn't differentiate between single, double and aromatic bonds. I uploaded my own image, but the creator of the original one replaced it. Just thought I'd let editors know my version exists, in case they prefer it too and would like to use it.

Ben 15:36, 16 September 2006 (UTC).

I like the space-filling one. How come that isn't in the article? —Keenan Pepper 20:12, 16 September 2006 (UTC)
Plus, the one in the article now has a white background instead of a transparent one. I vote for Caffeine-3D-vdW.png. Who's with me? —Keenan Pepper 20:15, 16 September 2006 (UTC)
Sorry for the (too) bold replacing. I have added in the above gallery also the spacefill version. IMHO I think that ambient occlusion, cast shadows and silhouettes really help the perception of the 3d shape of the molecule. Probably this is more evident for molecules more complex than caffeine... The observation about the transparent background is pertinent. I'll correct the images. ALoopingIcon 20:40, 16 September 2006 (UTC)
ALoopingIcon, I like your space-filling model. I've put it in - hope this is OK.
Ben 20:52, 16 September 2006 (UTC)
The NCBI site ChemId Plus has several 3D renderings which I suggest you compare. I chose the one I prefer: E. It should be nice if all chem articles would use the same style. The ChemId pics can be rotated and zoomed. Can we introduce such things in the Wikipedia pics? Jclerman 23:01, 16 September 2006 (UTC)
JPEG compression is inappropriate for these images. —Keenan Pepper 23:05, 16 September 2006 (UTC)


This article has one particular weakness, and that's the way the following sections are organised:

# 3 Effects
   * 3.1 Overuse
         o 3.1.1 Caffeine intoxication
         o 3.1.2 Anxiety and sleep disorders
# 4 Pharmacology
   * 4.1 Metabolism
   * 4.2 Mechanism of action
   * 4.3 Tolerance and withdrawal

All of these should be under one heading, with five or six subheadings, and some logical progression from one section to the next. I hope to contribute something along those lines in the near future unless someone else gets there first. Regards. Samsara (talkcontribs) 09:12, 17 September 2006 (UTC)

whence ?

"...whence (like thence) is most often used nowadays to impart an archaic or highly formal tone to a passage and ... this effect is probably better realized if the archaic syntax of the word—without from—is preserved as well." From The American Heritage® Dictionary Jclerman 17:35, 17 September 2006 (UTC)

The very essence of the word originate suggest a separation from something. Thus, while "archaic", whence is a better word here. I don't see what the problem is with trying to impart an air of formality into an encyclopaedic article. Also to respond to second half of the american heritage entry, I deliberately didn't put in a "from"...that was a subsequent author. If you absolutely must have a more simple construction, at least change it so you don't barbarically end this sentence with a preposition. The beauty behind whence is it a)is a better word for the sense of the verb, and b) does away with the necessity of the preposition.--Josh Rocchio 21:02, 17 September 2006 (UTC)

Sky Rocket Caffeinated Syrup

Sky Rocket Caffeinated Syrup contains 100mg/oz caffeine. It comes in a 24.5oz bottle. The full bottle thus contains 2540mg of caffeine. If one was to drink the bottle within minutes, what would be the effect on this person? More importantly, would the person be all...dead?

I suggest that you carry this question to the reference desk. bibliomaniac15 03:54, 22 September 2006 (UTC)


Moved to Wikipedia:Reference_desk/Science#Overdose. - Samsara (talkcontribs) 15:33, 5 October 2006 (UTC)


In the second paragraph, it is stated that, "in North America, 90% of adults consume caffeine daily.[1]" The reference cited, [1], merely states the same, unsubstantiated claim. Is this a valid reference? I'd rather see the study from which the number is derived.

Phlake 05:59, 16 October 2006 (UTC)

If that article does not cite its sources, you should consider writing to the author of it to ask where he got his info. DMacks 19:05, 16 October 2006 (UTC)

L-theanine and tea

It appears that L-theanine (derived from tea) counteracts the jittery effect of caffeine. Can anyone advise on the particular pathway here - whether it is a linear response, whether it counteracts all the adverse side effects of caffeine, or is it more selective ?


Pete (email address removed)

Hang on...

'The first coffee house in Europe was opened Paris in the 1800's'

'In Britain, the first coffee houses were opened in London in 1652'

Does anyone else find it hard to believe these are both true? Indigenius 13:44, 22 October 2006 (UTC)

It sounds fishy. But consider this: a) Many, many people, when they say 'Europe', do not include the UK (I know, odd, but true). b) With colonialism, it is possible that one country or region could have easy access to a resource that would be impossible for another region to have. c) Now that I think about it, I read recently (in the Readers Digest of all things, I'll check it out) that the first coffee house in Europe was in Vienna, when a bag of beans was left there by the fleeing Ottomans. d) Just so you know, this article seems to support that there was a coffee house in London in the 17th century. Anchoress 13:07, 2 November 2006 (UTC)
External evidence for the London info, from the very reliable S. Pepys source. Mentions the Turks. Anchoress 13:09, 2 November 2006 (UTC) says the first coffee house in Europe was in Vienna. But this article says the first Viennese coffee house was the first in Central Europe. Ana... I haven't checked the sources in the Caffeine article at all yet. Anchoress 13:12, 2 November 2006 (UTC)
Given that the comment about Paris in the 1800s has been tagged {{citeneeded}} for a long time and we have other cites and WP articles that appear to contradict it, I've removed it. DMacks 10:27, 8 January 2007 (UTC)

Caffeine Allergy Supposed 08:19, 2 November 2006 (UTC)


It says in the article that increased urination is a symptom of caffeine overuse. Isn't that a normal effect of caffeine? You drink some coffee and it happeds, so why is it said in the overdose section?

I'm just curious, is it possible to inject caffeine? Any difference if I use coffee to get 100mg into my system or if I inject 100mg into my blood? No, I'm not going to try it^^. Cybesystem 16:29, 8 November 2006 (UTC)

I'm not answering from my knowledge of the article, but from my knowledge of caffeine, it has been shown that the diuretic function of the drug is more associated with 'spikes' in consumption; when a person consumes a consistent quantity of caffeine, the body quickly adapts and the diuretic effects are all but nullified. I believe one or more of the references in the article attest to that, if not I'm sure I can find some because it's now well-documented. Anchoress 16:58, 8 November 2006 (UTC)
I'm sure it would work to inject it, if you mixed it in a saline solution. I think the difference would be that all 100 mg would hit your system within seconds, instead of gradually entering from the gastric tract. You would feel it almost instantly, and it would be very uncomfortable. I've heard of people insufflating caffeine, and I personally have made a caffeine nasal spray. It kicks in all at once, and frankly it's rather scary. --BennyD 03:38, 13 November 2006 (UTC)

Missing info

Caffeine causes increased passage of stool and withdrawl causes constipation. I am not sure of the mechanism. —Preceding unsigned comment added by (talkcontribs)

Do you have a source? – ClockworkSoul 19:01, 9 November 2006 (UTC)

Molecular Formula does not Match the Pictures

The above picture does not represent the molecular formula: C8H10N4O2. Can someone please upload a correct picture. —The preceding unsigned comment was added by Thejox (talkcontribs) .

What specifically is wrong? Remember that carbon atoms in organic structure drawings are are sometimes not labeled explicitly, and that those implicit carbon atoms carry additional implicit hydrogen atoms to satisfy the valency of those carbon atoms? DMacks 07:42, 22 November 2006 (UTC)

The image is correct.

Topical caffeine

Today, I removed this bit from the article:

Caffeine is also in many topical products. The caffeine absorbs through the skin, directly into the bloodstream. Some of these products include caffeinated soap, caffeinated lip balm, caffeinated lotions, and even a caffeine patch.

Can anybody provide a source for the assertion that these products are more than a gimmick, that the caffeine is actually absorbed? – ClockworkSoul 19:15, 22 November 2006 (UTC)

Search PubMed/Medline with keywords "transdermal caffeine" and you'll find many references. Jclerman 20:13, 22 November 2006 (UTC)