A new acylated flavonoid glycoside from the flowers of Camellia nitidissima and its effect on the induction of apoptosis in human lymphoma U937 cells.

From the EtOH extract of the flowers of Camellia nitidissima Chi, a new acylated flavonoid glycoside, quercetin 7-O-(6"-O-E-caffeoyl)-ß-D-glucopyranoside (1), has been isolated, together with three known flavonoids: quercetin (2), quercetin 3-O-ß-D-glucopyranoside (3), and quercetin 7-O-ß-D-glucopyranoside (4). Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 was shown to inhibit proliferation and to induce apoptosis of human lymphoma U937 cells.