Isolation and Characterization of an Unknown Flavonoid in Dry Extracts from Passiflora Incarnata

HPLC analyses of dry extracts obtained from Passiflora incamata revealed the presence of ten known flavonoids whose structures were characterised by ionspray ionization tandem mass spectrometry; in addition, three unidentified peaks, F l, F2, and F3 appeared in the flavonoid region of the chromatogram. Two components were detected in F3 by on-line HPLC-ISI-MS analysis, named F3a and! F3b. F2 was demonstrated to be a structural isomer of schaftoside (1 ), and F3a of isoschaftoside (2), with apigenin as the common aglycone and molecular weight 564. Mass spectra and 2D-NMR experiments allowed us to assign the structure of 6-J3-D-glucopyranosyl-8-J3-D-ribopyranosyl apigenin to the new di-C-glycosylflavonoid F2.