Flavones and flavonols

Wollenweber, Eckhard

doi:10.1007/978-1-4899-2911-2_7

Cited by 33 publications

(24 citation statements)

References 246 publications

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“…Proanthocyanidins are known to become red in acidic solution (Aguinagalde, 1988), but acetic acid did not induce the red coloration in tt6 seedlings, suggesting that diphenylboric acid 2-aminoethyl ester induced acidification was not responsible. The appearance of visible colors upon staining with diphenylboric acid 2-aminoethyl ester is characteristic of flavones and flavonols with a trihydroxy-substituted A-ring (Wollenweber and Jay, 1988). In short, the red coloration of tt6 upon staining with diphenylboric acid 2-aminoethyl ester is consistant with an orthodihydroxy or orthotrihydroxy flavonoid that remains to be identified.…”

Section: Discussionmentioning

confidence: 99%

The colorless flavonoids of Arabidopsis Thaliana (Brassicaceae). I. A model system to study the orthodihydroxy structure

Sheahan

Cheong

Rechnitz

1998

American J of Botany

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The orthodihydroxy structure may mediate flavonoid coloration or antioxidant activity, making it of interest to floral or health food industries, respectively. In the first of two companion papers, the authors demonstrate a model system to study the orthodihydroxy structure in colorless flavonoids of Arabidopsis, with tools similar to those used upon the colored flavonoids. The system includes a fluorescent staining procedure to visualize colorless orthodihydroxy flavonoids at a subcellular level and to screen seedlings for rare genetic recombinants. The system also includes mutant lines to study the synthesis of colorless orthodihydroxy flavonoids, their potential role as antioxidants, and their potential risk as oxidative mutagens.

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Section: Discussionmentioning

confidence: 99%

The colorless flavonoids of Arabidopsis Thaliana (Brassicaceae). I. A model system to study the orthodihydroxy structure

Sheahan

Cheong

Rechnitz

1998

American J of Botany

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“…It has previously been reported that in several species found in arid environments a dense covering of wax and trichomes might help in decreasing water loss by lowering the amount of light absorbed by the leaf and the accompanying heat load (Ehleringer et al, 1976 ;Vogelmann, 1993). Flavonoids, especially flavonoid aglycones (Wollenweber, 1993), accumulate on the leaf surface of species from arid or semi-arid habitats and can act as filters for UV radiation (Wollenweber & Dietz, 1981 ;Fahn, 1988). In Olea europaea, another member of the Oleaceae that is widely distributed in the Mediterranean basin, the deposition of polyphenols in leaf hairs has been suggested to protect leaf cells from damage by UV radiation (Karabourniotis et al, 1998).…”

Section: mentioning

confidence: 99%

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Tattini¹,

Gravano²,

Pinelli³

et al. 2000

New Phytologist

204

175

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Experiments were conducted on Phillyrea latifolia plants grown under a dense overstorey of Pinus pinea (shade plants) or on seashore dunes (sun plants) in a coastal area of Tuscany (42m 46h N, 10m 53h E). Total integrated photon flux densities averaged 1n67 and 61n4 m mol m −# d −" for shade and sun sites, respectively. A leaf morphological-structural analysis, a qualitative and quantitative analysis of phenylpropanoids of leaf tissue and leaf surface, and a histochemical localization of flavonoids were conducted. The area of sun leaves reached 57% of that of shade leaves, whereas leaf angle (β), sclerophylly index (ratio of leaf d. wt : leaf area), and trichome frequency (trichome number mm −# ) were markedly greater in leaves exposed to full solar radiation than in leaves acclimated to shade. The total thickness of sun leaves was 78% higher than that of shade leaves, mostly owing to a greater development of both palisade parenchyma and spongy mesophyll. The concentration, but not the composition, of leaf tissue phenylpropanoids varied significantly between sun and shade leaves, with a marked increase in flavonoid glycosides in sun leaves. Flavonoids occurred almost exclusively in the upper epidermal cells of shade leaves. By contrast, flavonoids largely accumulated in the upper and lower epidermis, as well as in the mesophyll tissue of leaves that were acclimated to full sunlight. Flavonoid glycosides were found exclusively in the secretory products of glandular trichomes of P. latifolia leaves exposed to high levels of light ; luteolin 7-Oglucoside and quercetin 3-O-rutinoside were the major constituents. By contrast, verbascoside and an unidentified caffeic acid derivative constituted 72% of total phenylpropanoids secreted by glandular trichomes of shade leaves, whereas they were not detected in glandular trichomes of sun leaves. These findings suggest that the light-induced synthesis of flavonoids in glandular trichomes of P. latifolia probably occurs in situ and concomitantly inactivates other branch pathways of the general phenylpropanoid metabolism. This is the first report of the key role of glandular trichomes and of flavonoid glycosides in the integrated mechanisms of acclimation of P. latifolia to excess light.

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“…Methods for the separation and identification of flavonoid aglycones are of interest because of the widespread occurrence of these compounds in higher plants and their significant biological activity (Hahlbrock, 1981 ;Wollenweber, 1982;McClure, 1975). Numerous analytical techniques have previously been applied to the separation and identification of these compounds of which the most common are paper chromatography (Mabry et al, 1970;Van Sumere et al, 1961a, b), column chromatography (Mabry et al, 1970;Markham and Mabry, 1968;Seikel, 1962;Markham, 1975), thinlayer chromatography (TLC) (Mabry et af., 1970;Saleh, 1976;Schmidtlein and Herrmann, 1976) and spectrophotometric methods (Jurd, 1962;Markham, 1982;Agrawal, 1989;Mabry et al, 1970).…”

Section: Introductionmentioning

confidence: 99%

Separation and identification of flavone, flavonol, isoflavone and flavanone aglycones by capillary column gas chromatography

Koupai-Abyazani

Creaser

Stephenson

1992

Phytochemical Analysis

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A rapid and sensitive capillary column gas chromatographic method for the separation and identification of trimethylsilyl derivatives of flavonoid aglycones is reported. Well‐resolved, sharp and symmetrical peaks were obtained for a wide range of flavone, flavonol, isoflavone and flavanone aglycones with a variety of substitution patterns. Chromatographic behaviour and the effects of the number, position and type of the substituents on the retention times of these compounds have been defined.

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Flavones and flavonols

Cited by 33 publications

References 246 publications

The colorless flavonoids of Arabidopsis Thaliana (Brassicaceae). I. A model system to study the orthodihydroxy structure

The colorless flavonoids of Arabidopsis Thaliana (Brassicaceae). I. A model system to study the orthodihydroxy structure

Flavonoids accumulate in leaves and glandular trichomes of Phillyrea latifolia exposed to excess solar radiation

Separation and identification of flavone, flavonol, isoflavone and flavanone aglycones by capillary column gas chromatography

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