5.8- Dihydroxy-7-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... 

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. 

The seeds of Aframomum hanburyi K. Schum. (Zingiberaceae) are used as an antidote and ingredient in certain medicinal preparations in Cameroon [93]. From an acetone extract of the seeds of this plant, two sweet dihydroflavonols, 3-acetoxy-5,7-dihydroxy-4 -methoxyflavanone (68) and 2/ ,3/ -(+)-3-acetoxy-5,7,4 -trihydroxyflavanone (69), were isolated [93]. 3-Acetoxy-5,7-dihydroxy-4 -methoxyflavanone (68) was previously isolated from a different species, Aframomum pruinosum Gagnepain [112]. However, the sweetness intensities of these compounds were not indicated [93,112]. The previously known 2R,2>R)-dihydroquercetin 3-0-acetate (71) which was rated as 80 times sweeter than sucrose, was isolated from Tessaria dodoneifolia (Hook. Am.)... 

Acetoxy-5,7-dihydroxy-4 -methoxyflavanone (68) Aframomum hanburyi K. Schum. (Zingiberaceae) N.S. 93... 

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. 

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). 

Two 3-acetylated 3-hydroxyflavanones, 2i ,3-/ -3-acetoxy-4, 5-dihydroxy-7-methoxyflavanone (5) and 2, 3 -3-acetoxy-4, 5,7-trihydroxyflavanone (6) were isolated together with 4, 7-di-O-methylaromadendrin (7) and nerolidol (8) from the seeds of A. pruinosum [6],... 

A compound of this structure was first isolated from Matteucia orientalis by Munesada (12) and was named (-)-matteucinol. Later the isolation of matteucinol was reported from two species of Rhododendron, by Arthur and Hui (13) and by Tanabe, Kondo and Takahashi (14) however, the structuri assignments were not unequivocal since no spectral data was reported. Thus, this paper provides the first report of the spectral data of (-)-matteucinol and confirms the structure assignment as 5,7-dihydroxy-a,5-dimethyM -methoxyflavanone. 

Also obtained by peroxidatic degradation of 7,4 -dihydroxyflavanone or 7,4 -dihydroxy-3 -methoxyflavanone [5078],... 

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

Dihydroxy-4 -methoxyflavanone (Naringenin 4 -methyl ether = Iso-sakuranetin) Notholaena fendleri Kze. C16H14O5 124, 125... 

Dihydroxy-7-methoxyflavanone 121 (Naringenin 7-methyl ether = Sakuranetin) (230) ... 

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