Sweet chalcone

Figure 5. Conversion of bitter flavanone neohesperidosides to the corresponding intensely sweet chalcones and dihydrochalcones...

A number of neutral or bitter flavanone glycosides can be converted through ring opening to sweet chalcones (11) which, by additional hydrogenation, can be stabilized as sweet dihydrochal-cones (III) ... 

N.A. Triterpene saponins, chalcones flavonoids, isoflavonoids.99 312-511 Sweet-tasting tonic, treat sore throats, wheezing, coughs, canker sores, peptic ulcer, and gastritis. 

Influence of Sweeteners on Bitterness. In model system studies, natural fruit juice sugars were observed to raise the limonin threshold (24). An expanded study of natural and artificial sweeteners (26) demonstrated that sucrose, neohesperidin dihydro-chalcone (NHD), hesperetin dihydrochalcone glucoside (HDG) and aspartylphenylalanine methyl ester (AP) all raise the limonin threshold. At low sweetness levels HDG was the most effective followed by AP and NHD. Sucrose was without effect up to the 2% level. At sweetness levels equivalent to 1% sucrose, HDG, AP and NHD raised the limonin threshold in water from 1.0 ppm to 3.2, 2.5 and 1.3 ppm, respectively. Because of its high sweetness intensity, the concentration of NHD (16 ppm) was considerably lower than HDG (80 ppm) and AP (90 ppm). At 3-10% sucrose sweetness equivalency, the effectiveness of NHD increased substantially, sucrose moderately and HDG slightly, while that of AP decreased. Therefore, the sweeteners HDG, AP and NHD can effectively suppress limonin bitterness at low concentrations. 

Chalcones and Pihydrochalcones. Chalcones and dihydro-chalcones are Intensely sweet compounds (39) that are effective in raising the threshold at which the bitterness of naringin and limonin is perceived (46). As illustrated in Figure 5, chalcones are easily formed fromTlavanone glycosides by the addition of alkali and dihydrochalcones are formed from hydrogenated chalcones. Like the flavanone neohesperidosides, the chalcones and dihydrochalcones vary in the intensity of their taste response. 

This intense sweetener is made from grapefruit skins and it has a liquorice-like sweet taste. NHDC (9) has long been suggested as a potential intense sweetener but has only recently received legislative approvals. It is 900 times sweeter than sucrose, and chemically NHDC is the open chain analogue of neohesperedin a flavonone which occurs in Seville (bitter) oranges (Citrus aurantum). The dihydrochalcones are flavonoids which are ubiquitous in plants flavonones, chalcones and anthocyanins are also flavonoids. 

Ruscus aculeatus (butcher s broom, knee holy, knee holly, knee holm, Jew s myrtle, sweet broom, pettigree) has been used topically for vasoconstrictor treatment of varicose veins and hemorrhoids (15), and for chronic venous insufficiency, both alone (16,17) and in the combination known as Cyclo 3 fort, marketed in France, which contains an extract of R. aculeatus 150 mg, hesperi-din methyl chalcone 150 mg, ascorbic acid 100 mg, and metesculetol. 

Neohesperidin and naringin from bitter orange peel could serve as starting materials for the production of neohesperidin dihydro-chalcone (NHDHC) and naringin dihydro-chalcone (NDHC) both are sweeteners, with NDHC being as sweet as saccharin and NHDHC 20 times more so. 

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