Chemical analysis of flavonoid constituents of the seagrass Halophila stipulacea: First finding of malonylated derivatives in marine phanerogams

Abstract

The flavonoid fraction from the butanol extract of a Mediterranean sample of the seagrass Halophila stipulacea was chemically analyzed. A new malonylated flavone glucoside, genkwanin-4′- O-(6“-malonyl-glucopyranoside) ( 3), was isolated together with known flavone glucosides 4- 9, previously reported only from terrestrial sources. The structure of 3 was established by means of spectroscopic techniques, mainly NMR methods.