Trihydroxy-methoxyflavanone

Tetrahydroxy-4 -methoxyflavanone 7,3 -dihydroxy-4 -methoxyflavanone 4,2, 4 -trihydroxychalcone 4,4 -dihydroxy-2 -methoxychalcone naringenin liquiritigenin 7,4 -dihydroxy-3 -methoxyflavanone 5,7,4 -trihydroxy-3 -methoxyflavanone 5,7,3 -trihydroxy-4 -methoxyflavanone... 

In Table 15.8, the configurations of the sugars are assumed to be (S-d for glucose and glucuronic acid, and a-L for rhamnose, but the 7-(S-L-rhamnosyl(l 6)glucoside of 5,7,4 -trihydroxy-3 -methoxyflavanone (310) has been reported from Clematis armandi (Ranuncu-laceae). The (3-configuration of the rhamnose is not supported by NMR data, which indicates that the a-rhamnosyl sugar is present as expected. 

Only 15 newly reported simple dihydroflavonols are listed in Table 15.9. Several of the compounds are just simply the C-3 epimers of known (2i ,3i )-dihydroflavonols, e.g., (2R,3S)-3-hydroxy-5,7-dimethoxyflavanone (329) from the fern Woodsia scopulina (Dryopterida-ceae), (2i ,3S)-3,5,3, 4 -tetrahydroxy-7-methoxyflavanone (3-epipadmatin, 333) from Inula graveolens (Asteraceae),(2i ,3S)-3,5,3 -trihydroxy-7,4 -dimethoxyflavanone (337) from Lannea coromandelica (Anacardiaceae), and (2i ,3S)-3,5,7,3, 4, 5 -hexahydroxyflavanone (hovenitin III, 338) from the seeds and fruits of Hovenia dulcis (Rhamnaceae). The previously known (2i ,3i )-stereoisomer of hovenitin III has the trivial name ampelopsin. The same plant source has yielded the (27 ,37 )- and (27 ,3S)-epimers of 3,5,7,4, 5 -pentahydroxy-3 -methoxyflavanone, which are known as hovenitins I (340) and II (341), respectively. ... 

Hesperidin (= 3, 5,7-Trihydroxy-4 -methoxyflavanone-7-rutinoside) (flavanone-O-glycoside) Hyssopus, Mentha (Lamiaceae), Citrus spp., Poncirus trifoliata (Rutaceae) ACE (23% inhibition at 300 pM) [76]... 

Hydroxyflavanone represents the simplest compound of this class and is found in many legumes.9 2-Hydroxyflavanones, which are expected to be quite labile and converted to their corresponding flavones, have also been identified. These include the 2,5,7-trihydroxyflavanone 7-0-glucoside (8) in Malus spp.,80 2,5-dihydroxy-7-methoxyflavanone in Populus nigra, 1 6,7,8-trihydroxy-5-methoxyflavanone (9) in Isodon oresbius,82 and 2,5-dihydroxy-7-methoxyflavanone and its 6-C- and 8-C-methyl isomers (10) in Friesodielsia enghiana.83 All of these exhibit a lack of B-ring hydroxylation. 

Pisutthanan et al. (27) isolated six flavonoids out of which three were reported in this plant for the first time. They include 3,5,4 -trihydroxy-7-methoxyflavanone 5,7,3 -trihydroxy-5 -methoxyflavanone and 3,5,7-trihydroxy-4 -methoxyflavanone. Ling et al. (28) also isolated a total of eleven flavonoids from the leaf extract and identified them as eriodictyol 7,4 -dimethyl ether, quercetin 7,4 -dimethyl ether, naringenin 4 -methyl ether, kaempferol 4 -methyl ether, kaempferol 3-0-mtinoside, taxifolin 4 -methyl ether, taxifolin 7-methyl ether and quercetin 4 -methyl ether. Suksamram et al. (23) isolated the flavanones, isosakuranetin (5,7-dihydroxy-4 -methoxyflavanone), persicogenin (5,3 -dihydroxy-7,4 -dimethoxyflavanone), 5,6,7,4 -tetramethoxyflavanone and 4 -hydroxy-5,6,7-trimethoxyflavanone, the chalcones, 2 -hydroxy-4,4, 5, 6 -tetramethoxychalcone and 4,2 -dihydroxy-4, 5, 6 -trimethoxychalcone, and the flavones, acacetin (5,7-dihydroxy-4 -methoxyflavone) and luteolin (5,7,3, 4 -tetrahydroxyflavone) from the flowers. 

Hesperetin (3, 5,7-trihydroxy-4 -methoxyflavanone) [520-33-2] M 3023, (R,S) m 227-228 , pKEst 83-10.5 (phenolic). Crystallise it from EtOAc or ethanol. The natural 5(-) form crystallises from... 

Some cytotoxic flavonoids were isolated from Scutellaria indica [25] these were 2(S)-5,7-dihydroxy-8,2 -dimethoxyflavanone (50), 2(S)-5,7,2 -trihydroxy-8-methoxyflavanone (51), 2(S)-5,2 ,5 -trihydroxy-7,8-dimethoxyflavanone (52) and wogonin (5,7-dihydroxy-8-methoxy-flavone) (53), 5,7-dihydroxy-8,2 -dimethoxyflavone (54). 

S. baicalensis is used against various sicknesses in China and Japan. A number of flavonoids have been isolated from this plant, including viscidulin III (64), oroxylin A (57), wogonin (53), baicalein (55),viscidulin II (108), scullcapflavone II (62), chrysin (90), 5,7,2 -trihydroxy-8,6 -dimethoxyflavone (109) and (2R, 3R) - 3,5,7,2 ,6 -penta-methoxyflavanone (110) and a new flavone viscidulin III 2 -0-p-D-glucopyranoside (111) as well as eriodictyol (112) and rivularin (113) [43]. 

Figure 6.1. Flavonoids shown to be of nutritional significance are, for the most part, derivatives of either flavone or flavanone, e.g. quercetin (3,3,4,5,7-pentahydroxyflavone), rutin (quercetin-3-rutinoside), naringenin (4,5,7-trihydroxy flavanone), hesperetin (3,5,7-tri-hydroxy-4-methoxyflavanone) and hesperidin (hesperetin-7-rutinoside)...

Although appropriate incorporation studies have yet to be reported, the co-occurrence of a,2, 3,4,4 -pentahydroxychalcone (119), 2-methoxy-3, 4, 6-trihydroxy-2-benzylcoumaranone (120 R = Me), 2,3, 4, 6-tetrahydroxy-2-benzylcoumaranone (120 R = H), 3-0-methyl-2,3-rrans-fustin (121), and 3-0-methyl-2,3-cis-fustin (122) with mopanol (123) and peltogynol (124) in the heartwood of Tlrachylobium verrucosum lends credence to the proposal that the extra skeletal carbon atom in ring d of the latter compounds is derived from a 3-methoxyflavanone intermediate (121). 

Dihydro-5J-dihydroxy-2 3 hydroxy-4-methoxyphenyl)-4H-l-benzopyran-4-one, 9CI. 5JJ -Trihydroxy-4 -methoxyflavanone. Hesperetin. Hesperitin... 

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