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Flavones, Flavonols

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. [Pg.128]

Fig. 2.38. Basic chemical structure of flavones, flavonols and flavonoids (chalcones and aurones). Fig. 2.38. Basic chemical structure of flavones, flavonols and flavonoids (chalcones and aurones).
FLAVONE. FLAVONOL AND FLAVANONE CONTENTS IN FRUITS. VEGETABLES AND BEVERAGES PRESENTED AS AVERGAE VALUE STANDARD DEVIATION (MG/G FRESH WEIGHT)... [Pg.206]

Various analytical methods exist for flavonoids. These range from TLC to CE. With the introduction of hyphenated HPLC techniques, the analytical potential has been dramatically extended. Gas chromatography (GC) is generally impractical, due to the low volatility of many flavonoid compounds and the necessity of preparing derivatives. However, Schmidt et al. ° have reported the separation of flavones, flavonols, flavanones, and chalcones (with frequent substitution by methyl groups) by GC. [Pg.9]

For the analytical HPLC of a given subclass of flavonoids (flavones, flavonols, isoflavones, anthocyanins, etc.), the stationary phase, solvent, and gradient have to be optimized. [Pg.13]

Markham, K.R., Flavones, flavonols and their glycosides, Meth. Plant Biochem., 1, 197, 1989. [Pg.129]

Fabre, N. et al.. Determination of flavone, flavonol, and flavanone aglycones by negative ion liquid chromatography electrospray ion trap mass spectrometry, J. Am. Soc. Mass Spectrom., 12, 707, 2001. [Pg.132]

There are many branches to the flavonoid biosynthetic pathways, with the best characterized being those leading to the colored anthocyanins and proanthocyanidins (PAs) and the generally colorless flavones, flavonols, and isoflavonoids. Genes or cDNAs have now been identified for all the core steps leading to anthocyanin, flavone, and flavonol formation, as well as many steps of the isoflavonoid branch, allowing extensive analysis of the encoded enzymes (Table 3.1). In addition, several DNA sequences are available for the modification enzymes that produce the variety of structures known within each class of compound. [Pg.145]

The key enzymes involved in the formation of the hydroxycinnamic acids (HCAs) from phenylalanine and malonyl-CoA are now discussed in detail, while later sections address the branches of the flavonoid pathway leading to anthocyanins, aurones, flavones, flavonols, PAs, and isotlavonoids. This is followed by brief reviews of the regulation of flavonoid biosynthesis and the use of flavonoid genes in plant biotechnology. To assist the reader. Figure 3.1 presents the carbon numbering for the various flavonoid types discussed. [Pg.149]

Although flavonoids are found in many cellular compartments, it is only the mechanisms for vacuolar import that have been characterized in any detail. Alternative import mechanisms have been found that involve direct uptake, carrier proteins, or secondary modifications triggering importation. While commonalities are found for the import of anthocyanins, flavones, flavonols, and PAs, differences have also been observed for the different types of flavonoid. [Pg.180]

One of the hypotheses regarding evolutionary aspects of flavonoid diversification concerns the concept of flavonol accumulation in basal Angiosperms versus flavone accumulation in advanced families. Recently, some further efforts have been made towards defining the flavone/flavonols ratio in Dicotyledonae and their relation to lignification, indicating an increased tendency towards flavonol accumulation in lignified plants, whereas herbaceous species tend to accumulate more of the flavones. From the presented entries, it appears that flavone derivatives are more abundant in Lamiaceae than flavonols. In the Asteraceae, however, more data concern the flavonols. Both families are more or less herbaceous and members of the more advanced Angiosperms. [Pg.714]

Markham, K.R., Flavones, flavonols and their glycosides, in Methods in Plant Biochemistry, Dey, P.M. and Harbome, J.B., Series Editors, Vol. 1, Plant Phenolics, Harborne, J.B., Ed., Academic Press, London, 1989. [Pg.791]

Biogenetically, chalcones are the immediate precursors of flavanones, and some flavanones isomerize by ring opening into chalcones during isolation from plants or after chemical treatment with alkali. In turn, flavanones are intermediates in the biosynthesis of most other flavonoid groups, including flavones, flavonols, and isoflavonoids. For more information on the biosynthesis of flavonoids and flavanones in particular, the reader is referred to Chapter 3 and reviews by Heller and Forkmann. ... [Pg.919]

N.A. Flavonoids, flavones, flavonols, flavanones, coumaric acid, cinnamic acid, terpenoids.190 Treat diabetes, high blood pressure, asthma. [Pg.227]

The major types of bioactive constituents reported from Broussonetia papyrifera are the prenylated flavonoids, which include compounds of the diphenylpropane, chalcone, flavan, flavanone, flavone, flavonol, and aurone classes (Table 2), Fig. (7). An early study on B. papyrifera resulted in the isolation of two diphenylpropanes, broussonins A (29) and B (30), and a coumarin, marmesin (52), with antifungal activity [39]. Also, a diprenylated diphenylpropane derivative, kazinol F (31) [40], was reported as an antioxidant and tyrosinase inhibitory constituent [34]. [Pg.16]

Electron impact mass spectral data for conjugated, reduced and higher flavonoids have been summarized (B-75MI22201) and a review of electron impact, chemical ionization and field desorption mass spectra of flavones, flavonols, isoflavones and flavanones has been published (B-80MI22201). [Pg.603]

Table 5.38 b. Structures and 13C Chemical Shifts (<5C in ppm) of Selected Chalcones, Flavones, Flavonols, Isoflavones, Dihydro-flavones, Dihydroflavonols and Flavons (Aglycones). Spectra were Recorded in DMSO-d6, Except those of Flavone (CDC13) and 2 -Hydroxy-, and 2,2 -Dihydroxychalcone (D20/DMS0-d6 (2 7)) [989, 990]. [Pg.452]

An HPLC separation method with diode array detector and mass spectrometric (MS) detection equipped with atmospheric pressure ionization (API) was developed to determine flavone, flavonol, and flavanone in various vegetables, including green bean, broccoli, brussels sprouts, celery, kale, leek, onion, parsley, pepper (green, yellow, and red), and tomato (118). The flavonoids were analyzed as aglycones after acid hydrolysis. The extraction and acid hydrolysis conditions are based on previous work by Hertog et al. (119). Quercetin is the overall major flavonol, followed by kaempferol. The flavones, apigenin and luteolin, were found only in limited foods,... [Pg.808]

Flavonoids are widely distributed colored phenolic derivatives. Related compounds include flavones, flavonols, flavanonols, xanthones, flavanones, chalcones, aurones, anthocyanins, and cat-echins (see Chapter 29). Plants containing flavonoids with anticancer properties include ... [Pg.572]

Flavonoids are more or less intensely yellow colored pigments belonging either to the group of 2-phenyl-chromones 39 (flavones, flavonols) or 2-phenyl-chromanones 391 (flavanones, flavanonols) both groups have a backbone of 2-phenyl-l,4-benzopyrones ... [Pg.195]

Vaclavikova et al. [216] have investigated the effect of 13 flavonoid derivatives—aurones, chalcones, flavones, flavonols, chromones, and isoflavones—on 14 C-paclitaxel transport in two human breast cancer cell lines, the doxorubicin-resistant NCI/ADR-RES and sensitive MDA-MB-435. The compounds with known binding affinity toward the NBD of P-gp were selected. The four aurones studied most effectively inhibited P-gp-related transport in the resistant fine in comparison with other groups of flavonoids. The aurones also most effectively increased the intracellular accumulation of paclitaxel and decreased its efflux. The results obtained did not always correlate with the binding of flavonoid derivatives to P-gp, so this indicated that the binding was not the only factor influencing the transport of paclitaxel. The different aspects of inhibition of P-gp by polyphenols was recently reviewed by Kitagawa [212],... [Pg.274]

ATBC Flavones Flavonols 6.1 25,732 M Reduction of fatal myocardial infarction, no reduction of stroke (167,168)... [Pg.227]

The flavonoid group is very diverse and contains several compounds including flavanones, flavones, flavonols, dihydroflavonols, isoflavonoids, anthocyanins, flavan-3,4-diols, flavan-4-ols, and flavan-3-ols. Flavan-3-ols are the structural units of the polymeric compounds termed condensed tannins abundant in plants. [Pg.375]

Cytochrome P450 monooxygenases play two important roles in flavonoid biosynthesis. One involves the modification of ring C of flavanones, where they attack nonphenolic carbon atoms, thus resulting in the creation of new flavonoid classes such as flavones, flavonols, and isoflavonoids. The other involves the introduction of new hydroxyl groups on phenolic rings A and B, thus increasing the... [Pg.7]


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