ABSTRACT
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-ß-d-glucopyranoside (3), and (E)-resveratrol 3-O-ß-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. The results showed that derivatives 2a and 2b exhibited strong activities than compounds 2 against HT-29 and HeLa cell lines.
Subject(s)
Eleutherococcus/chemistry , Stilbenes/chemistry , Cell Survival/drug effects , Eleutherococcus/metabolism , HL-60 Cells , HT29 Cells , HeLa Cells , Humans , Magnetic Resonance Spectroscopy , Molecular Conformation , Plant Bark/chemistry , Plant Bark/metabolism , Plant Extracts/chemistry , Plant Stems/chemistry , Plant Stems/metabolism , Stilbenes/isolation & purification , Stilbenes/toxicityABSTRACT
A novel water-soluble polysaccharide (named ALP-1) was successfully isolated from the stem barks of Acanthopanax leucorrhizus by hot-water extraction, and further purified by Cellulose DEAE-52 and Sephadex G-100 chromatography. The structure of ALP-1 was characterized by HPLC, HPGPC, partial acid hydrolysis, periodate oxidation, Smith degradation, methylation, together with UV, IR and NMR spectral analysis. The antioxidant activities also were evaluated in vitro. Structural analysis revealed that ALP-1 was a homogeneous galactan with the average molecular weight of 169â¯kDa, composed of galactose, glucose, mannose and arabinose in a molar ratio of 6.1:2.1:1.1:1.0, owning a backbone structure of 1,6-linked α-d-Galp residues with some branches of α-d-Manp-(1â¯ââ¯3)-α-l-Araf residues at O-3 and α-d-Galp residues at O-4 of 1,6-linked α-d-Galp. Antioxidant assay showed that ALP-1 exhibited strong DPPH and HO scavenging activities, as well as ferric-reducing antioxidant power. These results provide a scientific basis for the further use of polysaccharides from A. leucorrhizus.
ABSTRACT
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 (IC50=10.16±1.95µM and 9.76±1.32µM) and MCF-7 (IC50=10.72±2.78µM) cell lines. The cytotoxic evaluation of these structurally modified stilbenoid derivatives have led to the establishment of a structure-activity relationship.