# Optochin

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Optochin
> Markdown URL: https://mediated.wiki/source/Optochin.md
> Source: https://en.wikipedia.org/wiki/Optochin
> Source revision: 1329687213
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 424978166
| ImageFile=Optochin.png
| ImageClass = skin-invert-image
| ImageSize=180px
| IUPACName=(4β,8α,9''R'')-6'-Ethoxy-10,11-dihydrocinchonan-9-ol
| OtherNames=Ethylhydrocupreine
|Section1= {{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo=522-60-1
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 4W030VS2OG
| PubChem=71542
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 534999
| MeSHName=Optochin
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 79283
| ChEBI_Ref = {{ebicite|changed|EBI}} 
| ChEBI = 86455
| SMILES = CC[C@H]1CN2CC[C@H]1C[C@H]2[C@@H](c3ccnc4c3cc(cc4)OCC)O
| InChI = 1/C21H28N2O2/c1-3-14-13-23-10-8-15(14)11-20(23)21(24)17-7-9-22-19-6-5-16(25-4-2)12-18(17)19/h5-7,9,12,14-15,20-21,24H,3-4,8,10-11,13H2,1-2H3/t14-,15-,20-,21+/m0/s1
| InChIKey = SUWZHLCNFQWNPE-LATRNWQMBV
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C21H28N2O2/c1-3-14-13-23-10-8-15(14)11-20(23)21(24)17-7-9-22-19-6-5-16(25-4-2)12-18(17)19/h5-7,9,12,14-15,20-21,24H,3-4,8,10-11,13H2,1-2H3/t14-,15-,20-,21+/m0/s1
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = SUWZHLCNFQWNPE-LATRNWQMSA-N
  }}
|Section2= {{Chembox Properties
| Formula=C<sub>21</sub>H<sub>28</sub>N<sub>2</sub>O<sub>2</sub>
| MolarMass=340.46 g/mol
| Appearance=
| Density=
| MeltingPt=
| BoilingPt=
| Solubility=
  }}
|Section3= {{Chembox Hazards
| MainHazards=
| FlashPt=
| AutoignitionPt=
  }}
}}

'''Optochin''' (or '''ethylhydrocupreine hydrochloride''') is a derivative of [quinine](/source/quinine) introduced in 1911 by Morgenroth and Levy with the intention to treat pneumococci infection.<ref>{{cite journal | pmc = 2125335 | pmid=19867915 | volume=22 | year=1915 | journal=J. Exp. Med. | pages=269–85 | author=Moore HF | title=The Action of Ethylhydrocuprein (Optochin) on Type Strains of Pneumococci in Vitro and in Vivo, and on Some Other Microorganisms in Vitro | issue=3 | doi=10.1084/jem.22.3.269}}</ref> In very high dilutions, it inhibits the growth of representatives of all four groups of pneumococci [in vitro](/source/in_vitro). That is the main reason it is now used in bacteriology for the differentiation of ''[Streptococcus pneumoniae](/source/Streptococcus_pneumoniae)'', which is optochin-sensitive, from the other, resistant [alpha-hemolytic](/source/alpha-hemolytic) streptococci, sometimes called the viridans streptococci because of the green colouration on blood agar around colonies.

The growth of [bacteria](/source/bacteria) that are optochin-sensitive will show a [zone of inhibition](/source/Antibiotic_sensitivity) around an optochin disc, while the growth of bacteria that are resistant to optochin will not be affected.   In vitro, a [minimum inhibitory concentration](/source/minimum_inhibitory_concentration) (MIC) of 1:10,000,000 will inhibit the growth of pneumococci, and 1:500,000 is bactericidal.<ref>{{cite web | url=http://chestofbooks.com/health/materia-medica-drugs/Pharmacology-Therapeutics-Prescription-Writing/Ethylhydrocupreine.html | title=Ethylhydrocupreine }}</ref>

==Resistance==
For decades, ''Streptococcus pneumoniae'' has been considered susceptible to optochin; but some strains have been found to be resistant to optochin in laboratory testing. This is notable because the emergence of optochin-resistant strains would invalidate the distinguishing test described above.<ref>{{citation |title=Optochin resistance in Streptococcus pneumoniae: mechanism, significance, and clinical implications |journal=Journal of Infectious Diseases |volume=184 |issue=5 |pages=582–590 |vauthors=Pikis A, Campos JM, Rodriguez WJ, Keith JM |year=2001 |pmid=11474432 |doi=10.1086/322803 |jstor=30137322|doi-access=free }}</ref>

== See also ==
* [Quinine](/source/Quinine)

==References==
{{reflist}}
{{Clinical microbiology techniques}}
Category:Bacteriology
Category:Quinolines
Category:Quinuclidines
Category:Phenol ethers
Category:Secondary alcohols
Category:Ethoxy compounds

---
Adapted from the Wikipedia article [Optochin](https://en.wikipedia.org/wiki/Optochin) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Optochin?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.