Flavonol pigments

Bloor, S.J. and Falshaw, R., Covalently linked anthocyanin-flavonol pigments from blue Agapan-thus flowers. Phytochemistry, 53, 575, 2000. 

Thompson, W. R., J. Meinwald, D. Aneshansley, and T. Eisner, Flavonols Pigments responsible for ultraviolet absorption in nectar guide of flower, Science, 177, 528-530 (1972). 

An examination of the flavonoids of Villarsia (Bohm et al., 1986) revealed a heterogeneous array of flavonol glycosides, based upon kaempferol, quercetin, and isorhamnetin, with each species exhibiting a unique assortment. Surprisingly, there were greater similarities between the pigment profile of V capensis and species from eastern Australia, V exaltata (Soland. ex Sims) G. Don from Tasmania and V. reniformis R. Br. from New South Wales, than with species native to... 

Fruifs and vegetables also contain ofher bioactive substances such as polyphenols (including well-known pigments anthocyanins, flavonols) and non-provitamin A carotenoids (mainly lycopene, lutein, and zeaxanthin) that may have protective effects on chronic diseases. Polyphenols and carotenoids are known to display antioxidant activities, counteracting oxidative alterations in cells. Besides these antioxidant properties, these colored bioactive substances may exert other actions on cell signaling and gene expression. 

The purpose of this chapter is to provide an overview of our present knowledge about the health benehts of pigments, particularly their effects on chronic diseases. We examine the effects of lipophilic (carotenoids, chlorophylls) and hydrophilic pigments (anthocyanins and flavones-flavonols), and curcumin. Descriptive and mechanistic studies are reviewed in regard to common chronic diseases. 

Asen, S., Eactors affecting formation of anthocyanin-flavonol co-pigment complexes and their importance on flower color. Plant Physiol, 47, 20, 1971. 

Flavonoids are a complex group of polyphenolic compounds with a basic C6-C3-C6 structure that can be divided in different groups flavonols, flavones, flavanols (or flavan-3-ols), flavanones, anthocyanidins, and isoflavones. More than 6,000 flavonoids are known the most widespread are flavonols, such as quercetin flavones, such as lu-teolin and flavanols (flavan-3-ols), such as catechin. Anthocyanidins are also bioactive flavonoids they are water-soluble vegetable pigments found especially in berries and other red-blue fruits and vegetables. 

Cuadra, P., Harborne, J.B., and Waterman, P.G., Increases in surface flavonols and photosynthetic pigments in Gnaphalium luteo-album in response to UV-B radiation. Phytochemistry, 45, 1377, 1997. 

Two classes of dimeric anthocyanins isolated from plants (section 10.2.6) have been identified in plants for the first time. One class includes pigments where an anthocyanin and a flavone or flavonol are linked to each end of a dicarboxylic acyl unit. The other class includes four different catechins linked covalently to pelargonidin 3-glucoside. During the last decade, seven new desoxyanthocyanidins and a novel type of anthocyanidin called P)Tanoanthocyanidins have been reported (Section 10.2.2). Toward the end of the 20th century, several color-stable 4-substituted anthocyanins, pyranoanthocyanins, were discovered in small amounts in red wine and grape pomace.Recently, similar compounds have been isolated from extracts of petals of Rosa hybrida cv. M me Violet, scales of red onion, and strawberries. About 94% of the new anthocyanins in the period of this review are based on only six anthocyanidins (Table 10.2). 

The occurrence of the diester structures of the malonic acid moiety in natural anthocyanin pigments has so far been reported in pigments from flowers of Eichhornia crassipes and chive. Allium schoenoprasum, where the anthocyanin-flavone and anthocyanin-flavonol disubstituted malonate structures were exhibited, respectively (Figure 10.8 and Figure 10.9). In some anthocyanins from flowers of Anemone coronaria, malonic acid is esterified with galactose in one end and tartaryl in the other end. ... 

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