A New Flavonoid from Carrichtera annua

Three flavonoid glycosides, $kaempferol-3-O-{\alpha}-L-rhamnopyranosyl-(1\;{\rightarrow}\;6)-{\beta}$-D-glucopyranoside$ or kaempferol-3-O-rutinoside (1), $isorhamnetic-3-O-{\alpha}-L-rhamnopyranosyl-(16)-{\beta}-D-glucopyranoside$ or isorhamnetin-3-O-rutinoside (2), and $quercetin-3-O-{\beta}-D-glucopyranosyl-(1 ${\rightarrow}\;2)-{\beta}-L-arabinopyranoside$ 3, the latter one being a new compound, were isolated from the methanolic extract of the aerial parts of Carrichtera annua. Mass spectrometry and 1D and 2D NMR spectroscopy allowed establishing the structure of these compounds.