title: Cytotoxic phenanthrenequinones and 9,10-dihydrophenanthrenes from Calanthe arisanensis.
abstract: Two new phenanthrenequinones, calanquinones B and C (2 and 3) and four new 9,10-dihydrophenanthrenes, calanhydroquinones A-C (4-6) and calanphenanthrene A (7), along with five known compounds (1 and 8-11), were isolated from an EtOAc-soluble extract of Calanthe arisanensis through bioassay-guided fractionation. Their structures were identified from spectroscopic data, and the compounds were tested for in vitro cytotoxic activity against human lung (A549), prostate (PC-3 and DU145), colon (HCT-8), breast (MCF-7), nasopharyngeal (KB), and vincristine-resistant nasopharyngeal (KBVIN) cancer cell lines. Compound 1 showed the highest potency (EC(50) < 0.5 microg/mL) against all seven cancer cell lines, with the greatest activity against breast cancer MCF-7 cells (EC(50) < 0.02 microg/mL). Generally, except for 7, compounds 2-11 also showed significant cytotoxic activity (EC(50) < 4 microg/mL) against some cell lines (especially PC-3 and MCF-7) in the panel.
authors.affiliation: Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: Chia-Lin
authors.initials: CL
authors.lastname: Lee
authors.forename: Fang-Rong
authors.initials: FR
authors.lastname: Chang
authors.forename: Ming-Hon
authors.initials: MH
authors.lastname: Yen
authors.forename: Donglei
authors.initials: D
authors.lastname: Yu
authors.forename: Yi-Nan
authors.initials: YN
authors.lastname: Liu
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Bastow
authors.forename: Susan L
authors.initials: SL
authors.lastname: Morris-Natschke
authors.forename: Yang-Chang
authors.initials: YC
authors.lastname: Wu
authors.forename: Kuo-Hsiung
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D008297:Male; D015394:Molecular Structure; D029595:Orchidaceae / Q000737:chemistry*; D010616:Phenanthrenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014750:Vincristine / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010616:Phenanthrenes; D011809:Quinones; D014750:Vincristine