Talk:Small molecule

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"Small molecule" gets 8082 hits in pubmed, so I'm sure we can find a few... :)

To start, how about these:

Just as a start... — Scientizzle 21:23, 8 May 2008 (UTC)

I have the feeling I have asked a silly question: I was looking for a paper with a definition in it, which is a waste of time, in particular, I was looking for a nature reviews as they give a definition of some words on the side. but I suppose that if everyone concurs on the definition I can just cite one of these (I might actually read more than the abstract on the first one, it seems interesting (and short)). Thanks --Squidonius (talk) 22:44, 8 May 2008 (UTC)
As if to ask. I check Artificial transcription factor which refers to protein only. --Squidonius (talk) 22:59, 8 May 2008 (UTC)

See also: too specific?[edit]

Does anyone else think that See Also section is getting populated with items that are overly specific. I might focus on adding broader terms, such as neurotransmitter, where appropriate. Since the article is rated top importance for the pharmacology project, I think that we should aim the material for as broad of an audience is possible. Shanata (talk) 11:23, 4 November 2009 (UTC)

Agreed. I went ahead and trimmed the list. Boghog (talk) 13:42, 10 February 2011 (UTC)

Molecular weight cutoff[edit]

is that really so that the upper limit for a small molecular weight molecule goes to 800 daltons. however as far as absorption is concerned, we generally draw the line at 300 daltons. —Preceding unsigned comment added by (talk) 12:09, 10 February 2011 (UTC)

A reasonable MW cutoff is at least 500 (see Lipinski's Rule of Five) and there are orally active antibiotics whose MW is as high as 800. So I think 800 is a reasonable cutoff. Boghog (talk) 13:42, 10 February 2011 (UTC)

It's a reasonable cutoff if you can cite a source for it. --Genya Avocado (talk) 23:31, 28 May 2013 (UTC)

A small molecule is defined as one that can rapidly diffuse across cell membranes and hence have the possibility to be orally available. Of orally available drugs, the macrolide antibiotics are at the high end of the molecular range, 700–900 Daltons.[1] Boghog (talk) 03:42, 29 May 2013 (UTC)


  1. ^ Macielag MJ (2012). "Chemical properties of antibacterials and their uniqueness". In Dougherty TJ, Pucci MJ. Antibiotic Discovery and Development. p. 801–2. ISBN 978-1-4614-1400-1. The majority of [oral] drugs from the general reference set have molecular weights below 550. In contrast the molecular weight distribution of oral antibacterial agents is bimodal ... between 340 and 450 Da but with another group in the 700–900 molecular weight range. 

Small molecules are often considered superior........[edit]

With all due respect to the parties involved, the material inserted with this edit seems to represent a severely limited understanding of pharmacology.

On top of just being plain wrong, there are a number of obvious WP policies which the statement seems to contravene, including WP:WEASEL and, given the fact this thing is cited to an unrecoverable 1991 Toronto star article, apparently WP:V.

I would highly recommend we take a second look at eliminating this line. NickCT (talk) 20:21, 30 July 2013 (UTC)

Actually rereading, I see the "considered superior" part was removed which mitigates the WP:WEASEL concerns; however, this statement is still just plain wrong on the basis that many many small molecule drugs can't be administered orally. NickCT (talk) 20:32, 30 July 2013 (UTC)
With all due respect, the above statement seems to represent a severely limited understanding of drug development. No biologic can be orally administered whereas most small molecules that have been approved as drugs (see table below) can. The key word is small molecule drug. Of course not all small molecules can be given orally. However the pharmaceutical industry works quite hard (as documented in [3], [4], and [5]) in making sure that the majority that are brought to market are orally active. Hence oral bioavailability is a key differentiator between small molecule drugs and biologics. Boghog (talk) 21:23, 30 July 2013 (UTC)
I agree that we need a working citation. Here is one that could be used to support the statement:[1]


  1. ^ Ganellin CR, Jefferis R, Roberts SM (2013). "Chapter 5.2 How do SMDs differ from biomolecular drugs?". Introduction to Biological and Small Molecule Drug Research and Development: theory and case studies (Kindle ed.). New York: Academic Press. ASIN B00CXO99RG. Table 5.13: Route of Administration: Small Molecules: oral administration usually possible; Biomolecules: Usually administered parenterally 
I have replaced the 1991 Toronto Star citation with the one directly above. Boghog (talk) 22:04, 30 July 2013 (UTC)
I have also modified the sentence to remove any possible misinterpretation. Boghog (talk) 22:56, 30 July 2013 (UTC)
Below is a table of the top 20 drugs by total prescriptions in 2011 ("Top products of 2011 by total prescriptions" (PDF). Pharmacy Times. ) (note: duplicates are the same drug from different manufacturers). It is striking that every single one of these is a small molecule that is also orally bioavailable.
Top 20 drugs by total prescriptions
rank drug class route of administration
1 hydrocodone / acetaminophen small molecule oral
2 hydrocodone / acetaminophen small molecule oral
3 levothyroxine sodium small molecule oral
4 lisinopril small molecule oral
5 Lipitor small molecule oral
6 Simvastatin small molecule oral
7 Plavix small molecule oral
8 Singulair small molecule oral
9 Azithromycin "small molecule"
(macrolide antibiotic)
10 Crestor small molecule oral
11 Nexium small molecule oral
12 levothyroxine sodium small molecule oral
13 metoprolol tartrate small molecule oral
14 hydrocodone / acetaminophen small molecule oral
15 Synthroid small molecule oral
16 Lexapro small molecule oral
17 Proair HFA small molecule oral
18 Ibuprofen small molecule oral
19 Trazodone HCl small molecule oral
20 Amoxicillin small molecule oral
The top 20 drugs by dollars ("Top products of 2011 by total dollars" (PDF). Pharmacy Times. ) include the biologics Humira, Enbrel, Remicade, Neulasta, Rituxan, and Epogen, none of which are orally bioavailable. The remainder of this top 20 list are all orally bioavailable small molecules. Boghog (talk) 06:14, 31 July 2013 (UTC)
Ok. Well with the rephrasing and re-referencing of the sentence in question I think most of my concern were essentially addressed. Thanks for your time and attention. NickCT (talk) 12:09, 31 July 2013 (UTC)


Humans have obviously been making "small molecules" for a long time -- well before the need for the term itself. The article should provide a citation that indicates when this term was introduced, and if identifiable, by whom. Google Ngram Viewer suggests that the collocation took off between 1950 and 1970, but I haven't examined the actual matches to see whether these represent the pharmaceutical sense or not. (talk) 17:24, 26 April 2015 (UTC)

No Longer my Quality Question[edit]

§I am just wondering if " sonic hedgehog " is correct terminology mentioned in inset at bottom right of article, i.e.: Cell culture example of a small molecule as a tool instead of a protein. in cell culture to obtain a pancreatic lineage from mesodermal stem cells the retinoic acid signalling pathway must be activated while the [--see-- sonic hedgehog --] pathway inhibited, which can be done by adding to the media anti-shh antibodies, [--see-- Hedgehog --] interacting protein or cyclopamine, the first two are protein and the last a small molecule.[8] [1]

p.s. NOTE: I found interesting terminology clarification at (talk) 23:43, 6 February 2016 (UTC)

  1. ^ this article