2 -Methoxy flavone

Rhamnetin (3,3 -4, 5-tetrahydroxy-7-methoxy flavone, 7-methyl quercitin) [90-19-7] M 316.3, m >300"(dec), several phenolic pKs -7-10.5. Crystd from EtOH. 

Trimethylsilyl derivatives of ten hydroxy- and methoxyhydroxyflavonoids have been studied by the GC-FTIR technique." " The correlation found between retention and gas-phase IR data was used in structural identification of compounds having very similar chromatographic behavior. The shift of the carbonyl frequency gave information on the presence of substitution. Some hydroxy- and methoxy-substituted flavones have been studied following carbon dioxide supercritical fluid chromatography on polymethylsiloxane capillary columns using flame ionization and FTIR detection." " " ... 

Liu, Q., Sang, W., and Xu, X., Solvent effects on infrared spectra of 5-methyl-7-methoxy-iso-flavone in single solvent systems, J. Mol. Struct., 608, 253, 2002. 

In kaplanin, the p configuration of the sugar in the 5-hydroxy-7-methoxy-8-C-p-glucosyl-flavone was indicated by H NMR and supported by H- H COSY. H and C NMR and HETCOR spectra gave the precise location of the glucose moiety. 

Scutellaria baicalensis Georgi S. macrantha Fisch. China Baicalein, baicalin, wogonin, beta-sitosterol, wognoside, 7-methoxy-baicalein, 7-methoxynorwogonin, skullcap flavones.33 Antibacterial, antiviral, antipyretic, antiinflammatory, antitumor. 

Graveolbioside D chrysoeriol 4, 5,7-trihy- droxy-3 - methoxy- flavone Apium graveolens,2T Petroselinum crispum (parsley),14 Luffa echinata ... 

Isorhamnetln glycoside (3,5,7,4 -tetrahydroxy-3 -methoxy-flavone glycoside)... 

Margariten (5,7-dlhydroxy-4 -methoxy-8-C-B-neohesperidosylflavone) 2"-0-3-D-xylosylvltexin (5,7,4 -trihydroxy-8 (2"-0-3-D-xylosyl-C-3-D-glucosyl) flavone... 

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. 

Diosmin (= 3, 5,7-Trihydroxy-4 -methoxy-7 -0-rutoside) (flavone-O-glycoside) Diosma crenulata (Rutaceae) ACE (44% inhibition at 300 pM) [76]... 

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