Corrinoid
{{Short description|Class of chemical compounds}}
Image:Corrin-IUPAC.svg numbering system, there is no 20 position. Positions 21-24 were numbered 20-23 in earlier literature.{{cite journal|jstor=2415001|title=The Structure of the Corrin Nucleus from X-ray Analysis|author=Dorothy Crowfoot Hodgkin|journal=Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences|volume=288|number=1414|date=1965-11-16|pages=294–305|doi=10.1098/rspa.1965.0219|bibcode=1965RSPSA.288..294H|s2cid=95235740}}]]
Corrinoids are a group of compounds based on the skeleton of corrin, a cyclic system containing four pyrrole rings similar to porphyrins.{{cite book
|last1=Cracan|first1=Valentin |last2=Banerjee|first2=Ruma
|editor1-first=Lucia|editor1-last=Banci |series=Metal Ions in Life Sciences |volume=12
|chapter= Chapter 10 Cobalt and Corrinoid Transport and Biochemistry
|title=Metallomics and the Cell |year=2013 |pages=333–374 |publisher=Springer |isbn=978-94-007-5560-4|doi=10.1007/978-94-007-5561-1_10|pmid=23595677 }} electronic-book {{ISBN|978-94-007-5561-1}} {{issn|1559-0836}} electronic-{{issn|1868-0402}}
These include compounds based on octadehydrocorrin, which has the trivial name corrole.{{cite web|url=http://www.chem.qmul.ac.uk/iupac/misc/B12.html|title=The Nomenclature of Corrinoids: Recommendations 1975|year=1975|publisher=IUPAC-IUB Commission on Biochemical Nomenclature (CBN)|access-date=2006-06-19|archive-url=https://web.archive.org/web/20121028035348/http://www.chem.qmul.ac.uk/iupac/misc/B12.html|archive-date=2012-10-28|url-status=dead}}
The cobalamins (vitamin B12) are the best known members of the group. Other prominent examples include cobyrinic acid and its {{chem name|hexaamide}} {{chem name|cobyric acid}}; cobinic acid and its hexaamide cobinamide; {{chem name|cobamic acid}} and cobamide.
Compounds containing the "Cob-" prefix (not corrin) are cobalt derivatives, and may include an oxidation state, as in "Cob(II)alamin". When cobalt is replaced by another metal or hydrogen, the name changes accordingly, as in ferrobamic acid or hydrogenobamic acid.
Reactions with cyanide
A solution of aquacyano-corrinoids, such as cobalamin or cobinamide, reacts with free cyanide in an aqueous sample. The binding of cyanide to the corrinoid cobalt center leads to a color change from orange to violet.{{Cite book|title=Inorganic Chemistry of Vitamin B12|last=Pratt|first=J.M.|publisher=Academic Press|year=1972|page=44}} Quantification of the cyanide content is feasible by UV-vis spectroscopy.{{Cite journal|last=Zelder|first=F.H.|year=2008|title=Specific Colorimetric Detection of Cyanide Triggered by a Conformational Switch in Vitamin B12 |journal=Inorganic Chemistry|volume=47|issue=4|pages=1264–1266|doi=10.1021/ic702368b|pmid=18205304}}{{Cite journal|last=Mannel-Croise, Zelder|year=2009|title=Side chains of cobalt corrinoids control the sensitivity and selectivity in the colorimetric detection of cyanide|journal=Inorganic Chemistry|volume=48|issue=4|pages=1272–1274|doi=10.1021/ic900053h|pmid=19161297}} Absorption of the corrinoid on a solid phase,{{Cite journal|last=Mannel-Croise, Zelder|year=2012|title=Complex samples cyanide detection with immobilized corrinoids |journal=ACS Applied Materials & Interfaces|volume=4|issue=2|pages=725–729|doi=10.1021/am201357u|pmid=22211318}} allows detection of cyanide even in colored samples, rendering this method appropriate for the analysis of cyanide in water, wastewater, blood, and food.{{Cite journal|last=Tivana, Da Cruz Francisco, Zelder, Bergenståhl, Dejmek |year=2014 |title=Straightforward rapid spectrophotometric quantification of total cyanogenic glycosides in fresh and processed cassava products|url=http://www.zora.uzh.ch/id/eprint/106811/1/1-s2.0-S0308814614002519-main.pdf|journal=Food Chemistry |volume=158 |pages=20–27|doi=10.1016/j.foodchem.2014.02.066|pmid= 24731309}}{{Cite journal|last=Mannel-Croise, Zelder|year=2012|title=Rapid visual detection of blood cyanide |url= http://www.zora.uzh.ch/id/eprint/75059/1/c2ay25595b.pdf|journal=Analytical Methods |volume=4|issue=9|pages=2632–2634|doi=10.1039/c2ay25595b|s2cid=96719554 }} Furthermore, this technology is non-toxic and considerably less prone to interference than the pyridine-barbituric acid colorimetry method.
References
External links
- {{MeshName|Corrinoids}}
- [https://web.archive.org/web/20121028035348/http://www.chem.qmul.ac.uk/iupac/misc/B12.html "The Nomenclature of Corrinoids" at chem.qmul.ac.uk]
- [https://archive.today/20071111234517/http://gold.zvon.org/ring_azacyclopentene3.html Goldbook]