Talk:Cyclodextrin

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cyclodextrins as drugs

There are currently five (5) clinical trials with “cyclodextrin” against ”NPC1” listed in clinicaltrials.gov . The EFSA has approved a health claim (reduction of postprandial glucose excursions) for alpha-CD. Why is that not enough evidence for cyclodextrins being investigated as treatments?

Untitled

In a cyclodextrin the primary hydroxyls line one rim of the toroid (or '6-rim') and the secondary hydroxyls line the other rim (the slightly wider '2,3-rim', thus alpha- and betacyclodextrin are bucket shaped), the result being that all the hydroxyls are on the outside and the cavity only has C-H bonds within it. This means that the external surface is hydrophilic and the internal surface hydrophobic. Thus in aqueous solution, inclusion complexes readily form with hydrophobic molecules, many of which demonstrate high directional selectivity relative to the axis of the toroid.

An interesting point is that the primary hydroxyls can point inwards towards the axis of the toroid. If the nerve agent sarin is complexed, these primary hydroxyls are perfectly oriented to attack the sarin molecule in an example of supramolecularly catalysed breakdown of a substance.

Cyclodextrin topology

  • The info dealing with the topological positioning of the hydroxyl groups within cyclodextrins was removed by a user with ip 137.43.156.123 in the revision of 20:10, 26 October 2005, maybe because such data was somewhat confusing. However I think this information is quite important to understand why cyclodextrins show their particular complexing capacity: for this reason I decided to put it back into the Structure section in what is hopefully a bit more clear fashion. If anyone has suggestions as to how to simplify the concept, modifications are welcome. Berserker79 13:05, 3 November 2005 (UTC)[reply]
  • I agree that the topology and orientation of the hydroxy groups is of high importance for the understanding of the chemical reactivity of cyclodextrins. I suggest to add the information of 2- and 3-hydroxy being at the wider brim and 6-hydroxy being on the narrow side of the toroid. Kajjo, 25. Jan 06

Chemical Structure

  • I'd like to suggest to update the chemical structure to reflect the correct axial and equatorial orientations of the 2-, 3- and 6-hydroxy groups in each glucose unit. I know this probably requires a redraw of the really nice graphic. However, since the inherent chirality of cyclodextrins is of importance as is the stereochemistry of sugars, this update appears to be desirable. Kajjo, 25. Jan 06
  • I'll try to redraw the cyclodextrins picture in the next days to include the suggested details: that could also help clarify the statament about the molecule topology. Don't know when it will be ready however. Berserker79 12:46, 27 January 2006 (UTC)[reply]

Industrial vs. Scientific Usage

  • I would like to add a paragraph on the analytical applications of cyclodextrins in enantioselective gas chromatography. Any comments on that?
  • Thus, we could change "Uses" to "Industrial Applications" and add the paragraph "Scientific Applications"

Kajjo, 25. Jan 06

  • I added a gamma CD Jpeg showing the torrid shape and spatial arrangement of the glucose monomers. It is simplistic but may give the reader a three dimensional perspective. Thoughts? An "Industrial applications" would be a great idea as it would allow an organized format for others to contribute their respective expertise. MDW 07. Dec.06

Sentence needs rewording

  • This sentence needs rewording: "Recently, the largest well-characterized cyclodextrin contains 32 1,4-anhydroglucopyranoside units, while as a poorly characterized mixture, even at least 150-membered cyclic oligosaccharides are also known."
That is just one example of many, the quality of the English in this article is quite dire and needs a major overhaul Azo bob (talk) 08:55, 19 May 2008 (UTC)[reply]

"Easily" available to whom?

  • Another sentence that needs rephrasing: "The production of cyclodextrins is relatively simple and involves treatment of ordinary starch with a set of easily available enzymes." I'm unaware that you can just walk into a store and buy the enzymes that are mentioned after this sentence. It sounds like they'd only be available to certain institutions that have the right connections. — Preceding unsigned comment added by 174.101.198.62 (talk) 04:10, 16 October 2013 (UTC)[reply]

References needed

This page is full of good information but is sadly lacking when it comes to specific references. M stone 04:05, 2 August 2007 (UTC)[reply]

concentrations

Does anyone know how concentrations are typically determined for cyclodextrins? By weight? What about crystal waters?

Have the long-term health effects of exposure to cyclodextrin been studied?

Have the long-term health effects of exposure to cyclodextrin been studied? —Preceding unsigned comment added by 64.105.0.100 (talk) 23:26, 12 October 2009 (UTC)[reply]

There is nothing to support the statement that cyclodextrins have application in the food industry, as stated. They are not FDA approved food additives. I don't see research showing their safety for consumption. I would like to discuss this issue with whoever inserted that into the listing. But, of course, that's impossible with this screwy Wikipedia game where no one is responsible for anything, and no discussion can take place. Beekeepers (talk) 19:21, 28 February 2010 (UTC)[reply]
The United States is not the only country on Earth, so the fact that they are not approved by the FDA doesn't immediately imply that they don't have application in the food industry somewhere. That said, the statement you're referring to is indeed missing support, so feel free to tag or remove it.
I don't understand what "screwy Wikipedia game" you're talking about. Are you talking about Wikipedia in general? If so, the talk page for the cyclodextrin article is not the place. —Keenan Pepper 23:22, 2 March 2010 (UTC)[reply]
I did a simple Google search and it revealed that you're completely wrong. All three common cyclodextrins are Generally Recognized As Safe by the FDA, so I added the references (from fda.gov) to the article. They were quite easy to find. —Keenan Pepper 23:44, 2 March 2010 (UTC)[reply]

Brain effects

Shu, Zeng, Wang, Covey, Zorumski, Mennerick

Cyclodextrins sequester neuroactive steroids and differentiate mechanisms that rate limit steroid actions

Br J Pharmacol. 2007 January; 150(2): 164–175.

Published online 2006 December 11. doi: 10.1038/sj.bjp.0706973

[C]yclodextrins form inclusion complexes with at least some steroids that are active at the GABA(A) receptor, such as (3alpha,5alpha)-3-hydroxypregnan-20-one (3alpha5alphaP, allopregnanolone). ... gamma-cyclodextrins can be useful, albeit non-specific, tools for terminating the actions of multiple classes of naturally occurring neuroactive steroids. PMID 17160009

PMC 2042897 — Preceding unsigned comment added by 99.190.133.143 (talk) 17:59, 22 April 2012 (UTC)[reply]

SBE-β-CD / SBE beta cyclodextrins (e.g. Captisol)

Captisol® is a patent protected, uniquely modified cyclodextrin, whose chemical structure was rationally designed to maximize safety and optimize interaction to improve the solubility, stability, bioavailability or lessen volatility, irritation, smell or taste.

Captisol® is a patent protected, uniquely modified cyclodextrin, whose chemical structure was rationally designed to maximize safety...

Captisol® is a polyanionic beta-cyclodextrin derivative with a sodium sulfonate salt separated from the lipophilic cavity by a butyl ether spacer group, or sulfobutylether (SBE). Captisol® is not a single chemical species, but comprised of a multitude of polymeric structures of varying degrees of substitution and positional/regional isomers dictated and controlled to a uniform pattern by a patented manufacturing process consistently practiced and improved to control impurities.

The selection of Captisol® and its desirable safety profile and drug solubilization properties was based upon extensive evaluations of the mono, tetra and hepta-substituted dominated compositions. Captisol® is the trade name for Ligand's modified beta-cyclodextrin technology.

Several hundred of pre-clinical and clinical studies have been performed and indicate that Captisol® is safe when administered parenterally or orally and does not exhibit the nephrotoxicity associated with beta-cyclodextrin. Relative to beta-cyclodextrin, Captisol® provides higher interaction characteristics and superior water solubility in excess of 100 grams/100 ml – a 50-fold improvement.[1]

Could any of the above be added as a specific sub-type cyclodextrin of the beta type. It seems if the above doesn't display the nephrotoxic effects usual to the beta class to which it belongs, that it's particular subtype would be note worthy enough for at least mention in a section of this article page. 71.32.253.184 (talk) 06:09, 28 May 2012 (UTC)[reply]

That seems too highly promotional to me. It would have to be rephrased to be added. -- Ed (Edgar181) 11:11, 3 July 2013 (UTC)[reply]

Toxicity (oral)

The renal toxicity of α-CD and β-CD after parenteral administration (Frank et al., 1976) as well as problems with a number of modified CDs have been well documented (Irie and Uekama, 1997; Thompson, 1997; Gould and Scott, 2005).

ABOVE QUOTE FROM:

Stella VJ, He Q

Cyclodextrins

Toxicol Pathol. 2008 Jan;36(1):30-42. doi: 10.1177/0192623307310945.

Full free text: http://tpx.sagepub.com/content/36/1/30.long

PMID 18337219

http://www.ncbi.nlm.nih.gov/pubmed/18337219


CITING

Frank DW, Gray JE, Weaver RN

Cyclodextrin nephrosis in the rat.

Am J Pathol 83:367–82. (1976)


Irie T1, Uekama K.

Pharmaceutical applications of cyclodextrins. III. Toxicological issues and safety evaluation.

J Pharm Sci. 1997 Feb;86(2):147-62.

PMID 9040088

http://www.ncbi.nlm.nih.gov/pubmed/9040088?dopt=Abstract


Thompson DO

Cyclodextrins—enabling excipients: their present and future use in pharmaceuticals.

Crit Rev Ther Drug Carrier Syst 14:1–104. (1997)

PMID 9043816

http://www.ncbi.nlm.nih.gov/pubmed/9043816?dopt=Abstract


Gould S, Scott RC

2-Hydroxypropyl-beta-cyclodextrin (HP-beta-CD): a toxicology review.

Food Chem Toxicol.

2005 Oct;43(10):1451-9.

Epub 2005 Apr 19.

PMID 16018907

http://www.ncbi.nlm.nih.gov/pubmed/16018907?dopt=Abstract



Stella and He state, regarding last cite, that:

An updated toxicology review on HP-β-CD was published recently (Gould and Scott, 2005).


Research: Cyclodextrin clears cholesterol plaques, etc.

In mice fed high-cholesterol diets, cyclodextrin cleared away plaques and helped prevent more plaques from forming, Latz and his colleagues found. The chemical also activated cholesterol metabolism that boosted clearance of the waxy substance from arteries, plus dampened inflammation responses that spur atherosclerosis.

Using blood vessel tissue from human patients with atherosclerosis, researchers found that cyclodextrin induced the same changes in the human cells as it did in the mice.

The study shows that cyclodextrin is a promising new treatment for atherosclerosis in humans. [1] 

Mike dill (talk) 05:28, 9 April 2016 (UTC)[reply]

In accordance with Wikipedia guidelines, a recent review paper was added, 3 Mar 2024.


How was the cyclodextrin administered to those atherosclerotic mice: orally? subcutaneously? IV? parenterally? Please add that to the article.

Phantom in ca (talk) 18:59, 10 April 2016 (UTC)[reply]

Notes on research that should be incorporated into article when we get around to it:

Frappyjohn (talk) 23:12, 28 December 2018 (UTC)[reply]

References

  1. ^ Science Translational Medicine, 2015. DOI: 10.1126/scitranslmed.aad6100

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