Cytotoxic Clerodane Diterpenoids and Their Hydrolysis Products from Casearia nigrescens from the Rainforest of Madagascar

• Published in: Journal of natural products (Washington, D.C.) Vol. 70; no. 2; pp. 206 - 209
• Main Authors: Williams, Russell B, Norris, Andrew, Miller, James S, Birkinshaw, Chris, Ratovoson, Fidy, Andriantsiferana, Rabodo, Rasamison, Vincent E, Kingston, David G. I
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.02.2007; Amer Chemical Soc; American Society of Pharmacognosy
• Subjects: anticarcinogenic activity; Antineoplastic Agents, Phytogenic; Antineoplastic Agents, Phytogenic - chemistry; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - pharmacology; Biological and medical sciences; caseanigrescen; Casearia; Casearia - chemistry; Casearia nigrescens; chemical structure; chemistry; Chemistry, Medicinal; clerodane diterpene; cultured cells; cytotoxicity; Diterpenes, Clerodane; Diterpenes, Clerodane - chemistry; Diterpenes, Clerodane - isolation & purification; Diterpenes, Clerodane - pharmacology; diterpenoids; Drug Screening Assays, Antitumor; Female; Flowers; Flowers - chemistry; General pharmacology; Humans; hydrolysis; Inhibitory Concentration 50; isolation & purification; Life Sciences & Biomedicine; Madagascar; Medical sciences; Molecular Structure; nuclear magnetic resonance spectroscopy; Pharmacognosy. Homeopathy. Health food; pharmacology; Pharmacology & Pharmacy; Pharmacology. Drug treatments; Plant Leaves; Plant Leaves - chemistry; Plant Sciences; Plants, Medicinal; Plants, Medicinal - chemistry; rain forests; Salicaceae; Science & Technology; spectral analysis; stereochemistry; Madagascar; Malagasy Republic; Africa; BARK; TWIGS; LEAVES; Rain forest; Cytotoxicity; Extract; NMR spectrometry; Medicinal plant; Acetal; Ovary; Dicotyledones; Acylal; Angiospermae; Flacourtiaceae; Tumor cell; Human; Terpenoid; Flower; Pharmacognosy; Plant leaf; In vitro; Biological activity; Two dimension spectrometry; Hydrolysis; Cell line; Plant origin; Diterpene; Isolation; Spermatophyta; Degradation product; Structural analysis
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np0605034

Bioassay-guided fractionation of the cytotoxic leaf and flower extract of Casearia nigrescens led to the isolation of four new clerodane diterpenoids, designated caseanigrescens A−D (1−4). These compounds were subject to hydrolysis to dialdehydes when stored in CDCl3. The structures of compounds 1−4 were determined using 1D and 2D NMR spectroscopy. All four compounds showed moderate cytotoxicity to the A2780 human ovarian cancer cell line, with an IC50 range of 0.83−1.4 μM.