(15E)-12,18-ジヒドロキシセネシオナン-11,16-ジオン

説明A pyrrolizidine alkaloid first isolated from Crotalaria usararnoensis E. G. Baker, this base has more recently been found in C. brevifolia and C. rnucronata. The alkaloid has [α]20D + 6.1° (c 0.38, EtOH) or + 7.1° (c 1.83, EtOH). It yields a picrate, m.p. 230- 2°C (dec.); picrolonate, m.p. 148-150°C (dec.); reineckate, m.p. 190-2°C (dec.) and methiodide, m.p. 229-230°C (dec.). Alkaline hydrolysis furnishes retronecine and retronecic acid, m.p. 177-9°C. It has been suggested that the base may be identical with Mucronatine (q.v.).