title: Altaicalarins A-D, cytotoxic bisabolane sesquiterpenes from Ligularia altaica.
abstract: Four new bisabolane sesquiterpenes, altaicalarins A-D (1-4), and three known analogues (5-7) were isolated from the roots and rhizomes of Ligularia altaica. The structures were elucidated by spectroscopic methods including 2D NMR techniques, and the structure of 1 was confirmed by single-crystal X-ray diffraction. The isolated compounds were also evaluated for cytotoxic activity against human lung carcinoma (A-549), human breast adenocarcinoma (MCF-7), epidermoid carcinoma of the nasopharynx (KB), and vincristine-resistant nasopharyngeal (KBVIN) cell lines, and 1 was found to show significant cytotoxicity, with EC(50) values of 3.4, 0.8, 1.0, and 0.9 microg/mL, respectively.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Tzu-Hsuan
authors.initials: TH
authors.lastname: Chen
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Bastow
authors.forename: Kuo-Hsiung
authors.initials: KH
authors.lastname: Lee
authors.forename: Dao-Feng
authors.initials: DF
authors.lastname: Chen
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D006801:Humans; D008968:Molecular Conformation; D018517:Plant Roots / Q000737:chemistry; D027343:Rhizome / Q000737:chemistry; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013237:Stereoisomerism; D014750:Vincristine / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D012717:Sesquiterpenes; D014750:Vincristine