title: Four new 6-nor5(6-->7)abeo-abietane type diterpenes and antitumoral cytotoxic diterpene constituents from the bark of Taiwania cryptomerioides.
abstract: Four new 6-nor-5(6-->7) abeo-abietane type diterpenes designated as taiwaniaquinone G, taiwaniaquinone H, taiwaniaquinol E and taiwaniaquinol F and eight known diterpenes, taiwaniaquinones A (5), D (6), E, F (8), and taiwaniaquinols A (9), B, C (11), D (12) were isolated from the bark of Taiwania cryptomerioides. Their structures were elucidated on the basis of spectroscopic studies. These twelve diterpenes were evaluated for in vitro antitumoral cytotoxic activity. The result demonstrated that compounds 5, 6, 8, 9, 11, and 12 bearing an aldehyde group possessed potent cytotoxic activity against KB epidermoid carcinoma cancer cell lines with IC50 values of 6.9, 7.2, 4.4, 8.3, 8.1, and 3.5 microM, respectively.
authors.affiliation: Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, Pingtung, Taiwan.
authors.forename: Chi-I
authors.initials: CI
authors.lastname: Chang
authors.forename: Jang-Yang
authors.initials: JY
authors.lastname: Chang
authors.forename: Ching-Chuan
authors.initials: CC
authors.lastname: Kuo
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Pan
authors.forename: Yueh-Hsiung
authors.initials: YH
authors.lastname: Kuo
mesh_terms: D045784:Abietanes / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor / Q000187:drug effects; D029779:Cupressaceae; D006801:Humans; D020128:Inhibitory Concentration 50; D007624:KB Cells / Q000187:drug effects; D008517:Phytotherapy; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D045784:Abietanes; D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts