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Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries
Published on: January 22, 2019
Cytotoxic principles from the formosan milkweed, Asclepias curassavica
Michael C Roy1, Fang-Rong Chang, Hsiao-Chu Huang
1Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan, Republic of China.
Abstract:
A series of cardenolides and related compounds have been isolated from the aerial parts and roots of the ornamental milkweed, Asclepias curassavica. Their structures were determined by spectroscopic and chemical methods. Among them, three derivatives of calactinic acid methyl ester (13-15), 19-nor-16 alpha-acetoxy-10 beta-hydroxyasclepin (16), 20 beta,21-dihydroxypregna-4,6-dien-3-one (19), and 3,4-seco-urs-20(30)-en-3-oic acid (22) are new compounds. The relative configuration of calactinic acid methyl ester (12) has been confirmed by X-ray diffraction analysis on its derivative 13. Most of the cardenolides obtained showed pronounced cytotoxicity against four cancer cell lines (IC(50) 0.01 to 2.0 microg/mL).
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