1. Cytotoxic Constituents from the Fruiting Branches of Callicarpa Americana Collected in Southern Florida⊥
- Author
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Jones, William P., Lobo-Echeverri, Tatiana, Mi, Qiuwen, Chai, Hyee-Byung, Soejarto, Djaja D., Cordell, Geoffrey A., Swanson, Steven M., and Kinghorn, A. Douglas
- Subjects
Plants, Medicinal ,Molecular Structure ,Plant Stems ,Callicarpa ,Antineoplastic Agents, Phytogenic ,Article ,Diterpenes, Clerodane ,Plant Leaves ,Disease Models, Animal ,Mice ,Fruit ,Florida ,Animals ,Humans ,Drug Screening Assays, Antitumor - Abstract
Bioassay-guided fractionation of the combined fruits, leaves, and twigs (fruiting branches) of Callicarpa americana, collected from a plot in a forested area in southern Florida, led to the isolation of six new clerodane diterpenes (1-6) and eight known compounds. The structures of 1-6 [12(S),16xi-dihydroxycleroda-3,13-dien-15,16-olide (1), 12(S)-hydroxy-16xi-methoxycleroda-3,13-dien-15,16-olide (2), 12(S)-hydroxycleroda-3,13-dien-15,16-olide (3), 16xi-hydroxycleroda-3,11(E),13-trien-15,16-olide (4), 3beta,12(S)-dihydroxycleroda-4(18),13-dien-15,16-olide (5), and 12(S)-hydroxycleroda-3,13-dien-16,15-olide (6)] were elucidated by interpretation of spectroscopic data and chemical methods. The absolute configuration at C-12 in 1 and 3 was ascertained using the Mosher ester technique. The cytotoxicity of all isolates was tested against a panel of human cancer cell lines, and compounds 1, 4, and 6, and the known compounds genkwanin, 16xi-hydroxycleroda-3,13-dien-15,16-olide, and 2-formyl-16xi-hydroxy-3-A-norcleroda-2,13-dien-15,16-olide were active (ED505 microg/mL). However, 1 was found to be inactive against human cancer cells implanted in mice using a hollow-fiber tumor model.
- Published
- 2007