Flavonoids from Ziziphus jujuba Mill var. Spinosa

Eight flavonoid compounds were isolated from the seeds of Ziziphus jujuba Mill var. Spinosa. On the basis of chemical and spectral analyses their structures were elucidated as swertish (1), puerarin (2), 6‴-feruloylspinosin (3), apigenin-6-C-β-d-glucopyranoside (4), spinosin (5), 6‴-feruloylisospinosin (6), isospinosin (7), and isovitexin-2″-O-β-d-glucopyranoside (8). Flavonoids 6 and 7 are novel compounds. Rotamers exist for compounds 1, 3 and 5, which are reported for the first time. Compounds 2, 4 and 8 were isolated from this plant for the first time. Spinosin and swertish possess significant sedative activity.