Twelve 6-oxygenated flavone sulphates from Lippia nodiflora and L. canescens

Abstract

From the aerial parts of the maritime plant Lippia nodiflora, 15 flavonoids, 3 flavone aglycones and 12 new flavone sulphates, have been isolated and identified. The new flavone sulphates are mono- and disulphates of nepetin, jaceosidin, hispidulin, 6-hydroxyluteolin and nodifloretin present as the sodium salts. These sulphates are the only flavone conjugates detected in this plant. Flavone trisulphates are additionally present in populations of this species from Malaysia and Saudi Arabia, but lack of plant material prevented their complete characterization. Analysis of the closely related species Lippia canescens showed that it has the same flavonoid pattern. By contrast, a third species L. triphylla showed a flavonoid pattern lacking flavonoid sulphates, but characterized by the presence of 7-glucuronylglucosides of luteolin, diosmetin and apigenin. This is the first finding of flavonoid sulphates in the Verbenaceae.