Glycoside naringin

Naringenin (5, 7, 4 -trihydroxyflavanone), isolated in pure form from dormant peach flower buds, strongly inhibited the growth of Avena coleoptiles at 4.6 X 10-4 M (71). Naringenin is the aglycone of the glycoside naringin. 

Acylations of carbohydrate derivatives such as alkyl glucosides and galactosides have also been successfully performed in ionic liquids [63]. Similarly, the flavonoid glycosides naringin and rutin were acylated with vinyl butyrate in ionic liquid media in the presence of a number of lipases, e.g., CaLB (Novozym 435), immobilized TIL, and RmL [119]. The products are of interest for application as strong antioxidants in hydrophobic media. 

However, a recent study reported that the glycoside naringin was recovered (0.02% of the administered dose) in urine as unchanged molecule, hence confirming those glycosides are absorbable [66],... 

Another important interaction is that of limonin with the bitter flavanone glycoside naringin. Both of these bitter substances are present in grapefruit juice and Guadagni et al. (25) found that they interact at subthreshold levels in an additive way. Less than threshold amounts of limonin or naringin contribute to the bitterness of a mixture of the two compounds. The bitterness of the mixture can be predicted by adding the taste-unit contribution of each component (taste unit = concentration/ threshold). 

Pig. I Aiiranlii pericarpiurn (1) two characteristic red-orange zones of tlavonoid glycosides naringin/neohesperidin (bitter), rutin/eriocitrin (non-bitter) at jRf 0,4-0.5. 

Flavanone-7-O-glycosides (naringin, prunin, narirutin, hesperidin, neohesperidin, and eriocitrin) in lemon juice DL-Lactic acid yoghurts, and beverages (wine, sake, beer, and a soft drink)... 

The glycoside naringin, prepared easily from grapefruit canning wastes, has also been suggested as a source of L-rhamnose 113),... 

Neohesperidose 0-a-L-Rhap-(l —> 2)-D-Gl(y> Glycosides (naringin, neohes-peridin)... 

Both enantiomers of rhamnose, 6-deoxy-mannose, occur naturally. L-Rhamno-se is a constituent of glycosides such as naringin (89) as well as hesperidin, and a constituent in plant tissues as well as of bacterial cell walls. a-L-Rhamnosida-ses have been employed to debitter fruit juices [145]. 

Figure 6.4 Esters of flavonoid mono- or di-glycosides (isoquercitrin 20, quercitin 21, rutin 22, naringin 23) produced by enzyme-catalyzed regioselective acylation.

The glycosides of normal flavonoids (Table VII), except naringin, showed some precipitation alone, and without exception, precipitation increased considerably when they co-reacted with a few moles of phloroglucinol. The chalcones tended to precipitate more completely than the true flavonoids, probably because of the more free and reactive phloroglucinol moiety. 

Dilute citrus juice (5 ml) with dimethylformamide (DMF, 10 ml) and 50 mM ammonium oxalate (10 ml), and then steam-bath for 10 min at 90°C. Cooling, adjust the volume to 50 ml with water, centrifuge (10 min at 2500 g), and then filter (Acrodisc, 5 and 0.45 /nm) the clarified juice. For standard preparation, prepare hesperidin (20 ppm) in DMF-water (2 1) solution and other flavanone glycosides (neohesperidin, eriocitrin, neoeriocitrin, naringin, and narirutin, 10 ppm) in the mobile phase. 

Spices (rosemary, sage, thyme) contain considerable amounts of flavonols and flavones, mainly in the glycoside form (154). Thus, phenolic analyses in spices were often considered in order to determine the optimum time for plant collection to give maximum flavonoid contents and for health benefits (154,155). Flavonoids (naringin, luteolin, apigenin, and chrysoeriol) were extracted from spices using a percolation process at room temperature with solvents (MeOH and EtOAc), and HPLC analysis was carried out (155). 

He suggested that the method might also be suitable for the determination of flavones and flavonols. This method is still widely used to measure naringin in grapefruit juice albeit it is not specific for naringin, it is a simple, rapid and inexpensive method of analysis. However, since grapefruit contains both bitter and nonbitter flavanone glycosides, Davis values are only a crude approximation of bitterness. 

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