Isolation, modification and cytotoxic evaluation of stilbenoids from Acanthopanax leucorrhizus.

Twenty natural stilbenoids (1-20), including seven new stilbenoids (2, 4-7, 19, 20) and thirteen known stilbenoids (1, 3, 8-18), were isolated from the stem barks of Acanthopanax leucorrhizus, and six modified stilbenoid derivatives (1a, 2a, 4a, 4b, 7a and 17a) were obtained via methylation, demethylation and isopentenylation of the corresponding isolates (1, 2, 4, 7 and 17). These stilbenoids were structurally characterized by comprehensive analysis of their spectroscopic data and comparison with literature information, and evaluated for their cytotoxic activities against three human tumor cell lines (leukemia HL-60, hepatoma SMMC-7721 and breast carcinoma MCF-7) in vitro by MTT assay. The results showed that compounds 1a, 4a and 4b showed potent selective cytotoxicity against SMMC-7721 (IC=10.

Structural Modification of Stilbenoids from Acanthopanax leucorrhizus and Their Cytotoxic Activity.

A new cis-stilbenoid, 1,9-dihydroxy-10-methoxy-6H-dibenzo[b,f]oxocin-6-one (2) was isolated from the AcOEt extract of the stem barks of Acanthopanax leucorrhizus, along with three known stilbenoids, 9-hydroxy-10-methoxy-6H-dibenzo[b,f]oxocin-6-one (1), 5-O-methyl-(E)-resveratrol 3-O-β-d-glucopyranoside (3), and (E)-resveratrol 3-O-β-d-xylopyranoside (4). Two derivatives (2a and 2b) were synthesized by the structural modification of compound 2, which exhibited certain cytotoxic activities against HT-29 and HeLa cell lines in vitro. All compounds were structurally characterized by comprehensive analysis of their spectroscopic data and comparison with literature information, and evaluated for their cytotoxic activities against three human tumor cell lines (HL-60, HT-29, and HeLa) by the standard MTT assay in vitro.