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

Article abstract of DOI:10.1016/S0031-9422(00)84968-7

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.