Chemical Constituents From Two Medicinal Plants Of Compositae And Their Cytotoxicities Against Human Breast Cancer MCF-7 Cells

Two medicinal plants (Compositae), Saussurea cordifolia (Hemsl.) and Carpesium faberi (Winkl.) have been chemically and biologically investigated for the first time.Nine new and forty-six known compounds were isolated by using column chromatography (CC) over silica gel, RP-C18,MCI gel, Sephadex LH-20, PTLC and semipreparative HPLC. Their structures, especially the stereochemistry of the new compounds, were characterized on the basis of extensive spectroscopic methods (IR, UV,1D-/2D-NMR,LR-/HR-ESIMS,Circular Dichroism)and some chemical transformations.Thirty-six naturally occurring compounds, including five C10-acetylenic glycosides (1-4,6), one lignan (5), six phenylpropanoids (7-12), eight megastigmenes (13-20), two sesquiterpenes (21,22), four monoterpenes (23-26), two coumarins (27,28), three sterols (29-31), one triterpene (32) and a few miscellaneous constituents (33-36), were isolated from the whole plant of Saussurea cordifolia. Compounds 1-5 were elucidated as new natural products. Selected compounds were evaluated for their cytotoxicity against human breast cancer(MCF-7)cells using the MTT assay, and (8E)-decaene-4,6-diyn-1-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (3) and 5a,6β-dihydroxystigmastane-3-O-β-D-glucopyranoside (31) were found to show moderate cytotoxic effects, with IC50 values of 29.7 and 23.0μg/mL, respectively.Nineteen secondary metabolites, including seventeen sesquiterpene lactones (37-53) and two diterpenoids (54,55), were isolated from the whole plant of Carpesium faberi. Compounds 37-40 were determined to be new stuctures.All isolated compounds (37-55) were tested for their cytotoxicity against human breast cancer (MCF-7) cells using the MTT assay, and 2,3-dihydroaromaticin (47) and telekin (49) were found to show significant cytotoxic effects, with IC50 values of 3.9 and 3.0μg/mL, respectively.