title: A novel cytotoxic C-methylated biflavone, taiwanhomoflavone-B from the twigs of Cephalotaxus wilsoniana.
abstract: A novel C-methylated biflavone, taiwanhomoflavone-B (1), together with known compounds, 7,4',7"-tri-O-methylamentoflavone, 6-C-methylnaringenin and apigenin-7-O-beta-glucoside were isolated from an ethanolic extract of Cephalotaxus wilsoniana. The structure of 1 was elucidated on the basis of spectroscopic analysis. Taiwanhomoflavone-B is cytotoxic with ED(50) values of 3.8 and 3.5 microg/ml, against KB oral epidermoid carcinoma and Hepa-3B hepatoma cells, respectively.
authors.affiliation: National Research Institute of Chinese Medicine, Taipei, Taiwan, R.O.C. kuoyh@cma23.nricm.edu.tw
authors.forename: Yao-Haur
authors.initials: YH
authors.lastname: Kuo
authors.forename: Shy-Yuan
authors.initials: SY
authors.lastname: Hwang
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Yang Kuo
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Lee
authors.forename: Shyh-Yuan
authors.initials: SY
authors.lastname: Li
authors.forename: Ya-Ching
authors.initials: YC
authors.lastname: Shen
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D032483:Cephalotaxus / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D015394:Molecular Structure; D018520:Plant Shoots / Q000737:chemistry; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D005419:Flavonoids; C474093:taiwanhomoflavone-B