Flavonoid citrus

Benavente-Garcia O, Castillo J, Marin FR, Ortuno A and Del Rio JA. 1997. Uses and properties of citrus flavonoids. J Agric Food Chem 45 4505-4515. 

Middleton E Jr. and Kandaswami C. 1994. Potential health-promoting properties of citrus flavonoids. Food Technol November 1994 115-119. 

There have been many survey studies of citrus flavonoids, yet by no means has an exhaustive analysis been performed for all species and cultivars. Surveys often are initiated by hydrolysis of tissue extracts and identification of the flavonoid aglycones present in the tissues. This provides a basis for subsequent identification of the glycosylated compounds present... 

Because of human consumption of plant and plant products, there has been much interest on the impact of flavonoids on human health and this has been recently reviewed [149, 150 and ref therein]. Additionally, Passamonti et al. [151] have recently reviewed the issue of bioavailability of dietary flavonoids. Citrus flavonoids have been shown to have many beneficial effects on human health including anti-inflammatory activity, anticancer activity, antioxidant activity, and protection against coronary heart disease [reviewed in 152-154]. This has led to... 

Benavente-Garcia O, CastiUo J (2008) Update on uses and properties of Citrus flavonoids new findings in anticancer, cardiovascular, and anti- inflammatory activity. J Agric Food Chem 56 6185-6205... 

Datla KP, Christidou MA, Widmer WW, Citrus flavonoid tangeretrn accumulates in the brain and pre-treatment protects against dopaminergic neuronal loss in a rat model of Parkinson s disease, Brit JPharmacol 135 350, 2002. 

Flavones and flavanones were less frequently consumed during the 4-day collection period. Flavones were not consumed at all by 38 participants, while 29 people did not consume any citrus flavonoids — flavanones. The interquartile range of intake of flavones was relatively limited, ranging from 0.0 to 2.0 mg/day. Flavone consumption was not normally distributed and was negatively skewed toward a lack of consumption of foods rich in flavones such as olives and lettuce. Likewise, flavanone intake was also not normally distributed with a mean flavanone intake of 1 mg/day compared to the median intake of 1.2 mg/day. This is accounted for by the fact that the range of flavanone intakes was very wide (0 to 239 mg/day), 36%i of participants not consuming any flavanone-rich foods. The main dietary... 

Manthey, J.A., Guthrie, N., and Grohmann, K., Biological properties of citrus flavonoids pertaining to cancer and inflammation, Curr. Med. Chem., 8, 135, 2001. 

Borradaile NM, de Dreu LE, Huff MW. 2003. Inhibition of net HepG2 cell apolipo-protein B secretion by the citrus flavonoid naringenin involves activation of phosphatidylinositol 3-kinase, independent of insulin receptor substrate-1 phosphorylation. Diabetes 52 2554-2561. 

These compounds are differentiated primarily by the oxidation state of the central three carbon atom unit. Thus, as shown in Figure 1, some compounds are classified as flavones, flava-nones, flavonols, anthocyanins, etc. (The A and B rings have been left off for clarity). A secondary means of differentiating flavonoids is by the position and numbers of attached hydroxy, methoxy or sugar units. In citrus, flavonoids usually occur as glycosides, although the polymethoxylated flavones are a notable exception. 

Hesperidin Solubility. Hesperidin, a tasteless flavanone glycoside, is the least soluble of all citrus flavonoids. It is found in practically every variety of citrus (5) and is the major flavonoid in sweet oranges and lemons. In fruit or leaves, hesperidin is found as a soluble complex which can be extracted with water or alcohol (5). During juice extraction, the complex is destroyed and hesperTdin slowly precipitates as fine, white, needle-shaped crystals. Once in the solid form, hesperidin can be redissolved in formamide, pyridine or in dilute alkali. 

Chromatographic methods were developed to separate a few of the citrus flavonoids from the complex mixture of citrus flavonoids. The early paper chromatographic methods for flavanones (22, 23) were difficult to quantitate because of band broadening and uneven solvent development. Several thin layer chromatographic (TLC) methods were developed to separate the bitter from the nonbitter flavanone glycosides (24, 25, 26, 27). 

Table II. Relative Bitterness of Citrus Flavonoid Aglycones...

Pectin, citrus flavonoids Rutaceae Citrus lemon L. Carper (1988) Potter (1995) Bmneton (1995)... 

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