(1R)-1,2-ジヒドロ-12-ヒドロキシセネシオナン-11,16-ジオン

A hepatotoxic alkaloid, the base has been isolated from Senecio adnatus D.C., S. hygrophilus Dyer & Sm. and S. piatyphyllus D.C. The alkaloid is only sparingly soluble in petroleum ether or hot H20, more so in Me2CO, EtOH, C6H6 or Et20 and readily soluble in CHCI3. It is laevorotatory with [α]_D - 45.09° (CHCI3). The perchlorate occurs as colourless prisms from H20, m.p. 222-3°C (dec.); the picrolonate, dark yellow needles, m.p. 205-6°C (dec.); aurichloride, m.p. 200-loC (dec.) and the methiodide, m.p. 216-7°C; [α]_D - 31.27° (EtOH). The alkaloid contains one hydroxyl group but no methoxyl or methylimino groups. On hydrolysis it furnishes platynecine, CSH1S0 2N, m.p. 148°C; [α]_D - 56.8° (CHCI3) and platynecic acid, ClOH140 4 , m.p. l54-5°C which is identical with senecic acid lactone.