491-51-0

Basic information

• Product Name: (2R,3R)-(+)-7-O-methyldihydroquercetin
• CAS NO: 491-51-0
• Molecular Weight: 318.283
• Mol File: 491-51-0.mol
• Article Data: 3

Chemical Properties

• CAS DataBase Reference: (2R,3R)-(+)-7-O-methyldihydroquercetin(CAS DataBase Reference)
• NIST Chemistry Reference: (2R,3R)-(+)-7-O-methyldihydroquercetin(491-51-0)
• EPA Substance Registry System: (2R,3R)-(+)-7-O-methyldihydroquercetin(491-51-0)

Safety Data

• Hazardous Substances Data: 491-51-0(Hazardous Substances Data)

Upstream product

• 186581-53-3 diazomethane 
• 480-18-2 taxifolin 
• 17654-26-1 trans-dihydroquercetin 
• 215257-15-1 3,3',4',5,7-pentahydroxy flavanone 

Relevant articles and documents

Methylation of Dihydroquercetin Acetates: Synthesis of 5-O-Methyldihydroquercetin

The major products of methylation of dihydroquercetin (1, dhq) with diazomethane have been identified as 7-O-methyldhq (9), 7,3′ -di-O-methyldhq (10), 7,4′-di-O-methyldhq (11), and 7,3′,4′ -tri-O-methyldhq (2). With dhq 3,7,3′,4′-tetraacetate (6), dhq 3,5,3′,4′-tetraacetate (5), dhq 3,3′,4′-triacetate (7), dhq 7,3′,4′-triacetate (8), and dhq 3-acetate (4) the same reaction affords mainly 5-O-methyldhq 3,7,3′,4′-tetraacetate (15), 7-O-methyldhq 3,5,3′,4′-tetraacetate (13), 7-O-methyldhq 3,3′,4′-triacetate (14), 5-O-methyldhq 7,3′,4′ -triacetate (25), and 7-O-methyldhq 3-acetate (12), respectively. The methylation of 8 is accompanied by intermolecular acetyl migration from phenolic oxygen to the hydroxy group of the heterocyclic ring. 5-O-Methyldhq (28) is accessible by deacetylation of 25. 5,7-Di-O-methyldhq (29), four known methyl ethers, 13 new and three known methyl ether acetates of dhq, and six new isomers with 2,3-cis stereochemistry were spectroscopically identified.

7-O-METHYL-(2R:3R)-DIHYDROQUERCETIN 5-O-β-D-GLUCOSIDE AND OTHER FLAVONOIDS FROM PODOCARPUS NIVALIS

In the course of a chemotaxonomic survey of New Zealand Podocarpus species, a number of new flavonoid glycosides have been isolated from P. nivalis.These are: luteolin 3'-O-β-D-xyloside, luteolin 7-O-β-D-glucoside-3'-O-β-D-xyloside, dihydroquercetin 7-O-β-D-glucoside, 7-O-methyl-(2R:3R)-dihydrokaempferol 5-O-β-D-glucopyranoside, 7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucopyranoside, 7-O-methylkaempferol 5-O-β-D-glucopyranoside and 7-O-methylquercetin 5-O-β-D-glucopyranoside.Diagnostically useful physical techniques for distinguishing substitution patterns in dihydroflavonols are discussed and summarized.Glucosylation of the 5-hydroxyl group in (+)-dihydroflavonols is shown to reverse the sign of rotation at 589 nm.Key Word Index- Podocarpus nivalis; Podocarpaceae; snow totara; gymnosperm; flavonoid glycosides; 7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucoside; 7-O-methylquercetin 5-O-β-D-glucoside; luteolin 3'-O-β-D-xyloside; luteolin 7-O-β-D-glucoside-3'-O-β-D-xyloside; FAB-MS; 13C NMR.