Note 545 — PART VI.—ALKALOIDS AND POISONOUS VEGETABLE PRINCIPLES SEPARATED FOR THE MOST PART BY ALCOHOLIC SOLVENTS. (continued 5)
Reading edition
A constituent of the Borneo arrow poison is “derrid,” a toxic principle obtained from a leguminous plant, the Derris elliptica; it is a resinous substance, which has not yet been obtained in the pure state. It is said not to be a glucoside, nor to contain any nitrogen (Greshoff, Ber., xxiii. 3537-3550).
The Comalis on the east coast of Africa prepare an arrow poison from the aqueous extract of the root of Oubaion, a tree closely related to Carissa Schimperii.
Oubain is prepared by treating the aqueous extract with lead acetate, getting rid of excess of lead by SH2, and concentrating in a vacuum. The syrup is boiled with six times its volume of alcohol of 85°, and allowed to cool in shallow vessels; crystals are obtained which are recrystallised, first from alcohol, and afterwards from water.
Oubain, C30H46O12, forms thin white nacreous lamellæ. It is tasteless, odourless, and neutral, almost insoluble in cold water, and soluble in boiling water; it dissolves readily in moderately concentrated alcohol, is almost insoluble in absolute alcohol, and insoluble in ether and chloroform. Its melting-point is 200°. The solution of oubain in water is lævorotatory [α]D = -340. It is a glucoside, yielding on boiling with dilute acids a sugar. It is very poisonous; 2 mgrms. will kill a dog of 12 kilos. weight in a few minutes, if subcutaneously injected; but, taken by the stomach, it produces no effect.—Arnaud, Compt. Rend., cvi. 1011-1014.