Flavones chrysin

B) Inhibition of arachidonic acid metabolism. Most flavonoids tested (flavone, chrysin, phloretin, flavanone, apigenin and kaempferol) inhibited... 

However, the effect of piperine on SULT and flavonoid status across the life cycle remains to be investigated. Induction of phase II metabolism appears to decrease the bioavailability and accelerate the excretion of flavonoids. For example, Siess et al.115 and Walle et al.116 reported flavones induced rat hepatic UGT activity in HepG2 and Caco-2 cells. This induction of UGT enhanced quercetin glucuronidation in Caco-2 cells. In addition to inducing UGT activity, the flavone chrysin inhibits hepatic SULT-mediated sulfation of acetaminophen and minoxidol." The impact of chrysin on the capacity of COMT action toward flavonoids has not been examined. Further, the effect of age on phase II modulation by piperine and chrysin has not been reported. Thus, information on the relationship between age and intake of flavonoids and other phytochemicals that also affect phase II metabolism is required. 

N-methylpiperidinyl, chlorophenyl flavone) (Chrysin) derivative CDK7... 

Flavone dyes having these stmctures are hydroxylated and methoxylated derivatives. The degree of hydroxylation varies from two in chrysin [480-40-0] (17) to six in gossypetin [489-35-0] (18). Those dyes containing not more than three hydroxyls are generally termed flavones whereas those containing up to and including six are flavonols. 

Chrysin (17) was the first flavone to be isolated in a pure form, and its stmcture was elucidated by identification of its alkaline degradation products (72—74). The stmcture was confirmed by synthesis (75,76). The same procedures were used to estabflsh the stmcture of other flavones and in so doing the foundation of flavone chemistry was laid (77). 

A solvent-free synthesis of flavones was recently reported by microwave-assisted reaction of phloroglucinol 231 and differently substituted /1-ketoesters 232 [148]. The reaction was simply carried out by mixing the phenol and the ester in an open test tube followed by irradiation for 2-3 min. The internal temperature reached 240 °C and yields were in the range from 68 to 96%. Scheme 85 describes the application of this procedure to the synthesis of the natural product chrysin 233. 

The retention behaviour of flavonoids has also been extensively studied on silica stationary phases using heptane, benzene or dichloromethane as weaker components of the binary mobile phase and ethyl acetate and methyl ethyl ketone as modifier. Flavones (3-hydroxy, 5-hydroxy and 7-hydroxyflavone, tectochrysin, chrysin, apigenin, genkwanin, baicalein), flavonols (galangin, pilloin, kaempferol, rhamnetin, quercetin, robinetin,... 

There are three categories of constituents in passionflower flavonoids, maltol, and indole alkaloids. Among flavonoids are chrysin (5,7-dihydro flavone), vitexin, coumerin, and umbelliferone (figure 6.6). The greatest accumulation of flavonoids occurs in the leaves (Menghini and... 

Meier B. (1995). Passiflora incarnata L.—Passion flower. Zeitschrift fur Phytotherapie. 16(2) 115-26. Medina JH, Paladini AC, Wolfman C, Levi de Stein M, Calvo D, Diaz LE, Pena C. (1990). Chrysin (5,7-di-OH-flavone), a naturally-occurring ligand for benzodiazepine receptors, with anticonvulsant properties. Biochem Pharmacol. 40(10) 2227-31. 

New 3-desoxyanthocyanidins have been prepared according to a Grignard reaction of some flavones with appropriate alkyl- and aryl-magnesium bromides. The reaction of 5,7-dihydroxyflavone (chrysin) with an excess of phenylmagnesium bromide in THF under reflux conditions, followed by hydrochloric acid hydrolysis, afforded 1 in Scheme 10.2. Flavylium salts bearing a substituent at the 4-position are important compounds since they are known to be less sensitive to nucleophiles, especially water, and they give only minor amounts of the colorless pseudobases. ... 

Seven new aglycones support the C-glycosidic bond in this class 5,7-dihydroxyflavone (chrysin) in Scutellaria5-hydroxy 7-methoxyflavone (tectochrysin) in Piper 5,7,2, 4, 5 -pentahydroxyflavone (isoetin) in Hordeum, 5,7,2, 3, 5, 6 -hexahydroxy-flavone in Polygala 3,5,7,4 -tetrahydroxy 3, 5 -dimethoxyflavone (myricitrin) in... 

Chrysin shows a similar effect which is much enhanced in tecto-chrysin, owing presumably to methylation of the 7-hydroxyl in techto-chrysin leaving only the keto-associated 5-hydroxyl free in that flavone. Opening the flavone heterocyclic ring to produce 2-hydroxychalcone leaves monophenol activity still partly suppressed because of the remaining carbonyl effect on oxidizability and H-bonding. Since the structure is relatively free to rotate about the ring-to-carbonyl bond, the suppression is less than in tectochrysin. 

The conversion of androstenedione to estrone is catalyzed by aromatase. Inhibition of aromatase (human estrogen synthetase) by several naturally occurring flavonoids, including quercetin, chrysin, and apigenin, has been described. The synthetic flavone 7,8-benzoflavone was most active. Aromatization of androstenedione was affected by several flavonoids, of which 7-hydroxy-flavone and 7,4-dihydroxyflavone were the most potent. 

Studies have shown that quercetin, kaempferol, and fisetin inhibited transcription with RNA polymerase II in permeabilized normal human fibroblasts (WI-38 cells) flavone and chrysin exhibited weak activity. Addition of quercetin to an ongoing transcription reaction arrested it promptly, suggesting that quercetin was inhibiting the elongation step. The effects of several flavonoids (quercetin, quercetagetin, myricetin, and baicalein) exhibited complex interactions with DNA and RNA polymerases, depending on the particular flavonoid and the enzyme species. 

Utilizing this reaction, total syntheses of naturally occurring flavones, namely a phytoalexin, homopterocarpin (92), and chrysin (93) and luteolin (94), which are promising chemotherapeutics for AIDS, have been achieved. 

Flavones Apigenin buteolin Chrysin Parsley, celery... 

Honey contains an extensive diversity of phenolic compounds as secondary constituents, notably flavonoids and phenolic acids (Arraez-Roman et al., 2006 Baltrusaityte et al., 2007 Estevinho et al., 2008). The flavonoid content reaches about 6000 mg/kg, consisting mainly of flavanones and flavones (Anklam, 1998). The main flavonoids are myricetin, tricetin, quercetin, hesperidin, luteolin, kaempferol, pinocembrin, chrysin, pinobanksin,... 

Anthraquinones, coumarins, flavonoids, and terpenoids alizarin, anthraflavic acid, bomeol, chrysin, emodin, eugenol, 4-ethylphenol, galangin, 7-hydroxy flavone, menthol (low), 4-methylumbelliferone (low), 1-naphthol, naringen (low),... 

Chrysin (=5,7- Dihydroxyflavone) (flavone) Widespread Passiflora coerulea (Passifloraceae), Pinus spp. (Pinaceae) HIV-1 protease (125 pM) [43]... 

Chrysin (= 5,7- Dihydroxyflavone) (flavone) Populus (Salicaceae), Escallonia (Saxifragaceae) spp. Aminopeptidase N (49% inhibition at 300 pM) [63]... 

Some bioactive flavones include aldose reductase inhibitors (apigenin 4 -methyl ether (acacetin), apigenin 7-0-apioside (apiin), 5,7-dihydroxyflavone (chrysin) and luteolin) antiinflammatory 5-LOX inhibitors (5,6,7-trihydroxyflavone (baicalein), 5,6,3, 4 -tetrahydroxy 7-methoxyflavone (pedalitin), 5,3, 4 -trihydroxy 6,7-dimethoxyflavone (cirsiliol, 6-0-methylpedalitin) and flavone) a COX inhibitor (flavone) iodothyronine deiodinase inhibitors (acacetin, chrysin and luteolin) a NADH and succinate dehydrogenase inhibitor (luteolin) millet-derived, goitrogenic inhibitors of thyroid peroxidase (flavone C-glycosides orientin and vitexin) and protein kinase inhibitors (acacetin, apigenin, baicalein, flavone, luteolin, 5,7,3, 4, 5 -pentahydroxyflavone (tricetin) and tricetin 3, 4, 5 -trimethyl ether). 

Dimethylallyl)-apigenin] (flavone) [8-( 1,1 -Dimethylallyl)-chrysin] (flavone)... 

Flavone, flavonol and flavanone aglycones Eriodictyol, naringenin, isosakuranetin, quercetin, fisetin, kaempferol, galengin, kaempferid, luteolin, apigenin, genkwanin, chrysin. ESi-Trap negative ion mode Fabre et al., 2001... 

---