First isolated by Tuson from the seeds of Ricinus communis (castor-oil seed),
the alkaloid was subsequently examined by Soave, Schultze and Evans. The base
crystallizes from H20 in colourless prisms or leaflets and sublimes at 170-lS0°C/
20 mm. It is soluble in hot H20 or CHCI3, only sparingly so in EtOH and insoluble in petroleum ether, is neutral in reaction, optically inactive and forms no
normal salts although the mercurichloride, m.p. 204°C has been prepared. The
alkaloid reduces KMn04 and may be hydrolyzed by alkalies to MeOH and
ricininic acid which forms brilliant, slender needles, m.p. 296-8°C (dec.). The
structure of ricinine has been confirmed by synthesis from 4-chloroquinoline.
Other syntheses have also been achieved. The base is not particularly toxic and
the poisonous character of castor-oil seeds has been shown to be due to a more
complex substance, ricin, the toxicity of which may be destroyed by heating.
