RETRORSINE ( -Longiboline)

Description

A hepatotoxic alkaloid present in several Senecio species including S. isatideus, S. longibolus and S. retrorsus and also in Erechtites quadridentata DC. The base yields colourless crystals from EtOH and has [α]¹⁸_D - 17.6° (EtOH) or - 62.4° (c 1.0, CHC13). The ultraviolet spectrum has a single absorption maximum at 217.5 ITlJ.1. It yields crystalline salts and derivatives, e.g. the nitrate hemihydrate, m.p. 145°C; 'perchlorate, m.p. 250°C; picrate, m.p. 197°C; methiodide, m.p. 266°C (dec.); [α]²⁸_D - 23.8° (H20); monophenylcarbamate, m.p. 200-2°C and a perbromide hydrobrornide. On alkaline hydrolysis it forms retronecine, m.p. 121-2°C; [α]_D + 50.2° (EtOH) and isatinecic acid, m.p. 148.5°C; [α]²⁰_D + 86° (H20).

References

Manske., Can. J. Res., 5,651 (1931)
Barger et al., J. Chern. Soc., 11 (1935)
Blackie., Pharrn. J., 138,84 (1937)
de Waal., Onderstepoort J., 12, 155 (1939)
de Waal., ibid, 14,445 (1940)
Adams, Govindachari.,J. Arner. Chern. Soc., 71, 1180, 1956 (1949)
Warren etal., ibid, 72, 1421 (1950)
Leisegang.,J. S. Afr. Chern. Inst., 3,73 (1950)