Category:FL7

Revision as of 20:21, 22 September 2009

Anthocyanidin, Anthocyanin

Upper classes : FL Flavonoid

2nd Class
FL7A	Anthocyanin	FL7D	3-Deoxyanthocyanin

Overview

Anthocyanin is ubiquitous, whereas 3-Deoxyanthocyanin is found in sorghum (Sorghum bicolor), maize (Zea mays), and gloxinia (Sinningia cardinalis).

The Greek word origin of anthocyanin is "flower" ἀνθός (anthos) and "blue" κυανός (kyanos). It was first used by Marquart (1835) to describe water-soluble pigments in red, blue, and purple from flowers. Nowadays, such water-soluble pigments from flowers and fruits are called anthocyan. The flavonoid backbone without sugar (shown below) is called anthocyanidin (it is called aglycon because it is devoid of glyco moiety), and structure with sugars is called anthocyanin. Except for carotenoid (yellow) or indigo (deep blue), most pigments of plant origin are anthocyanins.

References

• Marquart LC. "Die Farben der Bluethen. Eine chemisch-physiol." Abhandlung, Bonn, 1835 (Cited by Onslow MW. "The Anthocyanin Pigments of Plants," Cambridge University Press, 1925).

Target of fruit and flower color engineering

Anthocyanin contains 3 aromatic rings, and glycosylation at the 3-OH position is necessary for stabilizing the aromatic ring. The general color of anchocyanin is red in acidic environment and purple/blue in alkali. The colors are, however, dependent on many other factors such as additional modifications and metal ions as is suggested by multi-color flowers such as pansy (yellow, orange, purple, violet, deep blue).

References

• Kroon J. et al. Plant J. 1994 Jan;5(1):69-80 PMID 8130799
• Boss PK. et al. Plant Mol Biol. 1996 Nov;32(3):565-9 PMID 8980508
• Fukuchi-Mizutani M. et al. Plant Physiol. 2003 Jul;132(3):1652-63 PMID 12857844 (research paper on Blue Rose)

Biodiversity

The six common anthocyanidins are the product of three different branches.

Biosynthesis (continued from the chart in Flavonoid)
(red or orange)		(blue or magenta)		(blue or purple)
pelargonidin	hydroxylation	cyanidin	hydroxylation	delphinidin
		peonidin		petunidin
methylation by anthocyanin O-methyltransferase (AOMT)
				malvidin

All three classes exist in most angio- and gymnosperm orders, and hydroxylating enzymes (F3'H and F3'5'H) show high sequence homology throughout orders. However, genetic changes cause genus-specific inactivation of these pathways.

Database statistics データベース統計