title: Cytotoxic withanolides from the flowers of Datura metel.
abstract: Chemical investigation of a methanol extract of the flowers of Datura metel has led to the isolation of 10 new withanolides, withametelins I-P (1-8), 1,10-seco-withametelin B (9), and 12beta-hydroxy-1,10-seco-withametelin B (10), together with seven known withanolides. The structures of 1-10 were elucidated by means of spectroscopic methods, and the absolute stereochemistry of 1 was confirmed by single-crystal X-ray analysis. Compounds 1, 3, 4, and 6 exhibited cytotoxic activities against A549 (lung), BGC-823 (gastric), and K562 (leukemia) cancer cell lines, with IC50 values ranging from 0.05 to 3.5 microM.
authors.affiliation: State Key Laboratory of Virology, College of Pharmacy, Wuhan University, Wuhan 430072, People's Republic of China.
authors.forename: Yuanhu
authors.initials: Y
authors.lastname: Pan
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Wang
authors.forename: Xianming
authors.initials: X
authors.lastname: Hu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D032302:Datura / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004875:Ergosterol / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D008968:Molecular Conformation; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D004875:Ergosterol