Cyanidine

Structural formula
General
Surname	Cyanidine
other names	2- (3,4-dihydroxyphenyl) -3,5,7-trihydroxychromenium chloride; 3,5,7,3 ', 4'-pentahydroxyflavylium chloride; Cyanidine chloride;
Molecular formula	C 15 H 11 O 6 +
Brief description	violet solid (chloride)
External identifiers / databases
PubChem	128861
ChemSpider	114193
Wikidata	Q417606
properties
Molar mass	287.24 g mol −1 322.70 g mol −1 (chloride)
Physical state	solid (chloride)
Melting point	> 300 ° C (chloride, decomposition)
solubility	practically insoluble in water (chloride); soluble in ethanol (chloride); soluble in methanol and 0.1% hydrochloric acid;
safety instructions
GHS labeling of hazardous substances chloride	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Cyanidin is a group of the anthocyanidins counting dye . Cyanidin chloride is practically insoluble in water and is suitable as an indicator , since the red flavylium cation is deprotonated at a pH of 6–6.5 to a red-violet product with a quinoid structure. Up to pH 8, this color changes to royal blue through further deprotonation . At an even higher pH, extracts of black elder or red cabbage also show green color.

Occurrence

Cyanidin is found in glycoside form as anthocyanin in many plants, including red cabbage , red roses , hibiscus , blueberry , raspberry , plum , elderberry , blackberry , blood orange, and rhubarb . In the form of an iron / magnesium / calcium chelate complex , cyanidine causes the blue color of the cornflower ( Centaurea cyanus ).

Antirrhinin, Keracyanin, Prunicyanin, Sambucin (Cyanidin-3-O-rutinosid)
Chrysanthemine, kuromanine (cyanidin-3-O-glucoside)
Sambicyanine (Cyanidin-3-O-sambubiosid)
Cyanidin-3-O-glycoside in elderberry

Methyl ethers of cyanidine ( peonidine and rosinidine ) also occur naturally as glycosides.

Cyanine (cyanidin-3,5- O -diglucoside)
Rosinidine
Peonidin, paeonidin
Peonidin-3- O- glucoside

Cyanidin as an indicator

The structure of cyanidine changes depending on the pH of the environment. Since each structure has a different color, a solution containing cyanidin can be used to determine the pH value over almost the entire pH scale. The 3- O- glycosides and 3,5- O -diglycosides of cyanidine behave in the same way.

pH-related reactions of the anthocyanidins that cause the color changes.

pH approx. 1 - 3 - 5 - 7 - 8 - 9 - 10 - 11 - 13

literature

Norbert Welsch and Claus Chr. Liebmann: colors, nature technology. In: Art. 2nd edition 2006, Spektrum Akademischer Verlag, ISBN 3-8274-1563-2 .

Individual evidence

↑ ^a ^b ^c data sheet Cyanidin chloride, ≥95% (HPLC) from Sigma-Aldrich , accessed on February 12, 2019 ( PDF ).
↑ ^a ^b Entry on anthocyanins. In: Römpp Online . Georg Thieme Verlag, accessed on April 26, 2014.
↑ ^a ^b ^c Sujata V. Bhat, BA Nagasampagi, Meenakshi Sivakumar: Chemistry of Natural Products . Springer Science & Business Media, 2005, ISBN 978-3-540-40669-3 , p. 602 ( limited preview in Google Book search).
↑ Axxora.com: Cyanidin chloride ( Memento of March 11, 2007 in the Internet Archive ), accessed on September 11, 2013.
^ Albert Gossauer: Structure and reactivity of biomolecules , Verlag Helvetica Chimica Acta, Zurich, 2006, p. 422, ISBN 978-3-906390-29-1 .
↑ Peter Keusch, University of Regensburg: Anthocyanins as pH indicators and complexing agents ( Memento from July 9, 2009 in the Internet Archive ).

[Sigma-1] ta sheet Cyanidin chloride, ≥95% (HPLC) from Sigma-Aldrich , accessed on February 12, 2019 ( PDF ).

[röempp-2] Entry on anthocyanins. In: Römpp Online . Georg Thieme Verlag, accessed on April 26, 2014.

[Sujata_V._Bhat,_B.A._Nagasampagi,_Meenakshi_Sivakumar-3] Sujata V. Bhat, BA Nagasampagi, Meenakshi Sivakumar: Chemistry of Natural Products . Springer Science & Business Media, 2005, ISBN 978-3-540-40669-3 , p. 602 ( limited preview in Google Book search).

[4] Axxora.com: Cyanidin chloride ( Memento of March 11, 2007 in the Internet Archive ), accessed on September 11, 2013.

[Gossauer-5] Albert Gossauer: Structure and reactivity of biomolecules , Verlag Helvetica Chimica Acta, Zurich, 2006, p. 422, ISBN 978-3-906390-29-1 .

[test-6] Peter Keusch, University of Regensburg: Anthocyanins as pH indicators and complexing agents ( Memento from July 9, 2009 in the Internet Archive ).