Fruit flavone

JUSTESEN u, KNUTHSEN p and LETH T (1998) Quantitative analysis of flavonols, flavones, and flavanones in fruits, vegetables and beverages by high-performance liquid chromatography with photo-diode array and mass specfrometric detection, /C/u matogr A, 799, 101-10. 

Anthocyanins are colored flavonoids that attract animals when a flower is ready for pollination or a fruit is ready to eat. They are glycosides (i.e., the molecule contains a sugar) that range in color from red, pink, and purple to blue depending on the number and placement of substitutes on the B ring (see Fig. 3.7), the presence of acid residues, and the pH of the cell vacuole where they are stored. Without the sugar these molecules are called anthocyanidins. The color of some pigments results from a complex of different anthocyanin and flavone molecules with metal ions. 

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. 

FLAVONE. FLAVONOL AND FLAVANONE CONTENTS IN FRUITS. VEGETABLES AND BEVERAGES PRESENTED AS AVERGAE VALUE STANDARD DEVIATION (MG/G FRESH WEIGHT)... 

Five known natural product HDAC inhibitors can be consumed in the human diet butyrate, diallyl disulfide (DADS), flavones, pomiferin, and sulforaphane (SFN). These compounds are found in fiber, garlic, broccoli, and various fruits. The first clinical use of HDAC inhibitors come from the butyrate class. 

Native to South America and well acclimatized to the Mediterranean, Feijoa sellowiana Berg (Myrtaceae) is an evergreen bushy shrub. These shrubs produce a spherical berry fruit that is edible and consumed as human food. Interestingly, countries that consume this fruit daily have lower cancer incidence. One important component of this fruit is flavone (Fig. 3). 

Flavanones are 2,3-dihydroderivatives of flavones which have a saturated C-ring, and are mainly present in their glycosidic forms. In contrast to other flavonoid classes found in a wide range of foods and plants, flavanones are present mainly in citrus fruit and in some aromatic herbs such as ntint. However, reports on the isolation of antinticrobial flavanones from medicinal plants mainly concerned those belonging to the Leguntinoseae family. 

Normal phases (unmodified silica gel) are rarely employed, except for the occasional separation of weakly polar flavonoid aglycones, polymethoxylated flavones, flavanones, or isoflavones. The polymethoxylated flavones present in citrus fruits can, for example, be separated on silica gel columns. The big drawback is that solvent gradients cannot normally be run with normal phases. 

Jam, confectionery, and herb compositional data are presented in Table 4.12. Honey contains low levels of both flavonols and flavones, and the presence of the flavanone naringenin has also been documented. Fruit jams also contain low levels of flavonols and catechins, which generally reflect the flavonoid profile of the whole fruit. 

A comprehensive and critical review of food flavonoid literature has led to the development of a food composition database for flavonols, flavones, procyanidins, catechins, and flava-nones. This database can now be used and continuously updated to estimate flavonoid intake of populations, to identify dietary sources of flavonoids, and to assess associations between flavonoid intake and disease. However, there is a need for better food composition data for flavones, procyanidins, and flavanones as current literature is sparse particularly for citrus fruits, fruit juices, and herbs. In addition, anthocyanin food composition data are lacking although validated methods of determination are becoming available. 

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