Flavones apigenin

Phlomis consists of about 100 species, a dozen of which occur in Mediterranean Europe (Mabberley, 1997, p. 549). The study of interest here involves a study of the flavonoids of R lychnitys L., a small plant native to Mediterranean Spain (Tomas et ah, 1986). Those workers identified the common flavones apigenin, luteolin, and luteolin 3 -methyl ether (chrysoeriol) 7-0-glucosides and their respective /7-coumaroyl derivatives. A brief review of the literature revealed that Mediterranean species of Phlomis are characterized by the presence of the flavone methyl ether, whereas continental species appear to lack 0-methylated flavones. Species from India have been reported to lack flavones but accumulate flavonols. The suggestion was made that accumulation of flavonols represents an ancestral feature of the genus. 

Flavones Apigenin Artichokes 4.7 US Department of Agriculture 2007a... 

Flavones Apigenin, luteolin Beets, bell peppers, Brussels sprouts, cabbage, cauliflower, celery, chives, kale, lettuces, spinach, peppers, tomatoes, watercress... 

Cinnamic acid OH derivatives H J> H Caffeic acid / -Coumaric acid o-Coumaric acid CH Ferulic acid Cinnamic acid Sinapinic acid COOH Flavonoids Flavones Apigenin q JT 11 Luteolin R2 Flavanonol 1 i IJ R3 V >r (+)-Taxifolin OH 0... 

Flavonols (quercetin + kaempferol + myricetin) Flavones (apigenin + luteolin)... 

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,... 

Unlike the phytoestrogens mentioned earlier, flavones do not possess estrogenic activity. However, the flavones apigenin and luteolin act as potent inhibitors of aromatase and 17P-hydroxy-steroid oxidoreductase, enzymes involved in estrogen metabolism. Studies have also demonstrated these flavones and several glycosylflavones are potent goitrogens, particularly in association with millet consumption. 

Different model systems and different methods are used to evaluate the antioxidant properties of flavonoids. The stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), which changes color after being reduced by an antiradical compound, was employed to study the antioxidant properties of isoflavones genistein (42) and daidzein (40), flavones apigenin (23) and lute-... 

Flavones Apigenin buteolin Chrysin Parsley, celery... 

Methyl ethers and esters are also found as volatile constituents in a wide range of flowers and fragrant herbs. For example, methyleugenol is found in the essential oil of herbs such as sweet basil and in the floral headspace of a wide range of flowers.7"10 Defense compounds and phytoalexins are commonly O-methylated as well. These compounds include the 3 -O-methylated form of the flavonoid quercetin as well as the 7-O-methyl ester of the flavone apigenin (Fig. ll.l).11,12 While not within the scope of this paper, it should be noted that protein O-methylation is common.13,14 One interesting protein modification known to occur in Arabidopsis thaliana is the a-carboxyl methylation of prenylated proteins.15 This modification has been shown in mammals and yeast to be important in protein targeting and membrane association.16,17... 

Flavonoids stimulate spore germination in the soilborne phytopathogenic fungus Fusarium solani. Spore germination of F. solani f. sp. pisi, which causes disease in pea, is stimulated by flavanone hesperetin (141), flavone apigenin (101), the pterocarpan phytoalexin pisatin (142), and so on. In contrast, germination of the bean pathogen F. solani f. sp. phaseoli is stimulated by the pterocarpans maackiain (143) and medicarpin (129), and isoflavones biochanin A (144), and so on but not by pisatin.85... 

Chemical structures of flavonoids. These flavonoids consisted of three groups flavone (apigenin and lutolin), flavonols (flavonol, kaempferol, quercetin, myricetin, tangeretin, and nobiletin) and isoflavones (daizein, genistein, biochanin A, and equol). 

The information obtained from H NMR spectra of flavonoids indicates the skeleton protons and attached groups such as methoxyl and sugar or some acyl groups. Table 10 gives the H NMR data of some simple and methylated flavones apigenin (18), luteolin (6), cirsimaritin (2), genkwanin (16) and thymonin (162). 

Flavones Apigenin, luteolin, diosmin and diosmetin. Found mainly in herbs, parsley, celery, citrus fruits, olives, peppers, red grapes, and some beans. Antiproliferative effect [67,70-73], Antimitotic [79], Inactivation of carcinogenesis mediated by chemicals [90, 91, 92], Inhibition of angiogenesis [108, Cardiovascular properties [99,100, 114], 10-4,000... 

Parsley contains large quantities of the flavone apigenin and low levels of other flavonoids. The herb has been used to determine the effect of apigenin on oxidation status in humans in a short-term study, parsley/apigenin consumption pro-... 

FIGURE 25.1 Structures of nonsteroidal phytoestrogens. The most prevalent classes of phytoestrogens are (1) flavones apigenin (2) kaempferol (3) isoflavones daidzein (4) genistein (5) formononetin (6) biochanin A (7) lignans enterolactone (8) coumestans coumestrol (9) flavanones 8-prenylnaringenin. 

Flavones Apigenin Luteolin Tangeretin Nobiletin Citrus fruits and pear [11,13]... 

Flavones lack the 3-hydroxy group of flavonols and an-thocyanins. Although only two flavones, apigenin (5) and... 

In other instances, flavones and flavonols with particular patterns of oxidation are of sufficiently restricted distribution among plant groups to be useful for systematic purposes. For example, in addition to the usual flavones [apigenin (5), luteolin (4), and chryseriol (38) (Fig. 11.3), usually as the 7-(7-glucuronides], plants of the Lamiaceae, Scrophulariaceae, and related families frequently contain 8-hydroxyflavones, 6-hydroxyflavones, or 6-methoxyflavones in glycosidic combination. 8-Hydroxyflavones based on apigenin and luteolin are restricted to the Lamiaceae (Tomas-Barberan et al., 1988). 

For example, the validity of Dahlgren s proposed Liliiflorae was appraised by an examination of flavonoids (Williams et al., 1988). The flavonols quercetin (7) and kaempferol (6) occurred in about half the plants tested the flavones apigenin (5) and luteolin (4) were found less frequently. The limited diversity of flavonoid patterns argues for a more conservative treatment at the family level (Williams et al., 1988). 

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