Cytotoxic activity of flavonoids from the flowers of Chrysanthemum morifolium on human colon cancer Colon205 cells

A new p-hydroxyphenylacetyl flavonoid, diosmetin 7-(6 ''-O-p-hydroxyphenylacetyl)O-beta-D-glucopyranoside (1), was isolated from the flowers of Chrysanthemum morifolium Ramat. 'huaiju' cv. nov. (Compositae), together with five known flavonoids, luteolin (2), diosmetin (3), diosmetin 7-O-beta-D-glucopyranoside (4), diosmin (5), and scolimoside (6), and four known caffeoylquinic acid derivatives, macranthoin F (7), 3,5-dicaffeoylquinic acid (8), 1,3-dicaffeoyl-epi-quinic acid (9), and chlorogenic acid (10). The structure of 1 was elucidated by UV, IR, ESI-TOF-MS, 1D, and 2D NMR spectroscopic methods. Cytotoxic activity of compounds 1-5 against human colon cancer cell Colon205 was investigated using MTT assays. Compounds 2 and 3 showed significant cytotoxicities against Colon205, with their IC50 values being 96.9 and 82.9 mu M, respectively. However, compounds 1, 4, and 5 showed little cytotoxic activity.