title: Structure and stereochemistry of new cytotoxic clerodane diterpenoids from the bark of Casearia lucida from the Madagascar rainforest.
abstract: Bioassay-guided fractionation of a CH(2)Cl(2)/MeOH extract of the bark of Casearia lucida resulted in the isolation of 11 new clerodane diterpenes, namely, casearlucins A-K (1-11), and three known clerodane diterpenoids, rel-(2S,5R,6R,8S,9S,10R,18S,19R)-diacetoxy-18,19-epoxy-6-hydroxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (12), rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-methoxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (13), and rel-(2S,5R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-2-(2xi-methylbutanoyloxy)cleroda-3,13(16),14-triene (14). The structures of compounds 1-11 were established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. All compounds exhibited cytotoxicity activity against the A2780 ovarian cancer cell line, but none of the six compounds selected for testing in multiple cell lines showed significant selectivity.
authors.affiliation: Department of Chemistry, M/C 0212, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212, USA.
authors.forename: Chaturvedula V
authors.initials: CV
authors.lastname: Sai Prakash
authors.forename: Jeannine M
authors.initials: JM
authors.lastname: Hoch
authors.forename: David G I
authors.initials: DG
authors.lastname: Kingston
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001013:Aorta, Thoracic; D001943:Breast Neoplasms; D002417:Cattle; D002478:Cells, Cultured / Q000187:drug effects; D003110:Colonic Neoplasms; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D005260:Female; D019073:HT29 Cells / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D007938:Leukemia; D008175:Lung Neoplasms; D008270:Madagascar; D019684:Magnoliopsida / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010051:Ovarian Neoplasms; D024301:Plant Bark / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes