Antineoplastic agents. 398. Isolation and structure elucidation of cephalostatins 18 and 19.
Continued investigation of murine leukemia (P-388) active fractions from the African marine worm Cephalodiscus gilchristi has resulted in the discovery of cephalostatins 18 (1b) and 19 (1c). The structures were determined by interpretation of their highfield (500 MHz) 1H, 13C, and 2D NMR and HRMS. Both of these new methoxy steroidal alkaloids exhibited strong activity against the murine P-388 lymphocytic leukemia cell line (ED50 ca. 10(-3) microg/mL), a mini panel of human cancer cell lines (GI50 <10(-3) microg/mL), and the U.S. National Cancer Institute's 60 human cancer cell line panel (mean panel GI50 ca. 10(-9) M).
Cancer Research Institute and Department of Chemistry, Arizona State University, Tempe, Arizona 85287-2404, USA. bpettit@asu.edu
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D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000494:pharmacology; D002240:Carbohydrate Sequence; D002816:Chordata, Nonvertebrate / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010619:Phenazines / Q000302:isolation & purification* / Q000494:pharmacology; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013141:Spiro Compounds / Q000302:isolation & purification* / Q000494:pharmacology; D013256:Steroids; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D010619:Phenazines; D013141:Spiro Compounds; D013256:Steroids; C113744:cephalostatin 18; C113745:cephalostatin 19