Cytotoxic cardenolide glycoside from the seeds of Cerbera odollam.
ABSTRACT A cardenolide glycoside, 3 beta-O-(2'-O-acetyl-l- thevetosyl)-15(14-->8)-abeo-5 beta-(8R)-14-oxo-card-20(22)-enolide (2'-O-acetyl cerleaside A), was isolated from a methylene chloride extract of the seeds of Cerbera odollam, together with four known compounds: cerleaside A, 17 alpha-neriifolin, 17 beta- neriifolin and cerberin. Their structures were elucidated by spectroscopic methods. All compounds except cerleaside A exhibited cytotoxic activities against oral human epidermoid carcinoma (KB), human breast cancer cell (BC) and human small cell lung cancer (NCI-H187).
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ABSTRACT: Two new cardenolides, 3 beta-O-(D-2-O-methyldigitalosyl)-14 beta-hydroxy-5 beta-carda-16,20(22)-dienolide (1) and 3 beta-hydroxy-8,14-epoxy-5 beta-carda-16,20(22)-dienolide (2), and two known cardenolides, 3 beta-O-(D-digitalosyl)-14 beta-hydroxy-16 beta-acetoxy-5 beta-card-20(22)-enolide (3) and 3 beta-O-(D-digitalosyl)-14 beta-hydroxy-5 beta-card-20(22)-enolide (4), have been isolated from the leaves of Nerium oleander following a bioactivity-directed isolation of the MeOH extract, which showed central nervous system (CNS) depressant activity in mice at a dosage of 50 mg/kg i.p. Their structures were established on the basis of chemical and spectral data. Compounds 1, 3, and 4 were found to exhibit sedation in mice at a dosage of 25 mg/kg, although 2 had no effect on the CNS of mice at a dosage of up to 50 mg/kg.Journal of Natural Products 07/1997; 60(6):540-4. · 3.29 Impact Factor
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ABSTRACT: We have developed a rapid, sensitive, and inexpensive method for measuring the cellular protein content of adherent and suspension cultures in 96-well microtiter plates. The method is suitable for ordinary laboratory purposes and for very large-scale applications, such as the National Cancer Institute's disease-oriented in vitro anticancer-drug discovery screen, which requires the use of several million culture wells per year. Cultures fixed with trichloroacetic acid were stained for 30 minutes with 0.4% (wt/vol) sulforhodamine B (SRB) dissolved in 1% acetic acid. Unbound dye was removed by four washes with 1% acetic acid, and protein-bound dye was extracted with 10 mM unbuffered Tris base [tris (hydroxymethyl)aminomethane] for determination of optical density in a computer-interfaced, 96-well microtiter plate reader. The SRB assay results were linear with the number of cells and with values for cellular protein measured by both the Lowry and Bradford assays at densities ranging from sparse subconfluence to multilayered supraconfluence. The signal-to-noise ratio at 564 nm was approximately 1.5 with 1,000 cells per well. The sensitivity of the SRB assay compared favorably with sensitivities of several fluorescence assays and was superior to those of both the Lowry and Bradford assays and to those of 20 other visible dyes. The SRB assay provides a colorimetric end point that is nondestructive, indefinitely stable, and visible to the naked eye. It provides a sensitive measure of drug-induced cytotoxicity, is useful in quantitating clonogenicity, and is well suited to high-volume, automated drug screening. SRB fluoresces strongly with laser excitation at 488 nm and can be measured quantitatively at the single-cell level by static fluorescence cytometry.JNCI Journal of the National Cancer Institute 08/1990; 82(13):1107-12. · 14.34 Impact Factor
- Phytochemistry 01/1988; 27(11):3627-3631. · 3.05 Impact Factor