456 poisons : their effects and detection. [§ 569 . 
Theoetia neriifolia, and perhaps also from the Cerbera Odallam. It is soluble in 124 
parts of water at 14°, and is easily soluble in spirit, but not in ether. It is coloured 
by sulphuric acid red-brown, passing into cherry-red, and, then, in a few hours, into 
violet. On boiling with diluted acids, it splits up into sugar and theveresin. Both 
thevetin and theveresin are powerful heart poisons . 1 2 
§ 569. Strophantin. —The seeds of Strophanthus gratus, hispidus, and kombe contain 
a poisonous glucoside, or mixture of glucosides, known under the name of strophantin. 
The strophantins appear to differ chemically according to the particular plant 
from which they have been derived, and are designated by the letters g, h, and k :— 
.(/-Strophantin, crystalline, from Strophanthus gratus. 
A-Strophantin, amorphous, from Strophanthus hispidus. 
^-Strophantin, crystalline, from Strophanthus kombe. 
Whether the three chief strophantins are isomerides, or whether they are slightly 
impure substances, is doubtful; for, although much chemical work has been done, 
the results are neither concordant nor satisfactory. They all act as cardiac stimulants 
and diuretics, and have a digitalis effect on the heart. The strophantins are believed 
to have a less cumulative effect than digitalis, and not to constrict the blood-vessels 
so markedly. 
&-Strophantin, from the kombe plant, according to Braund and Closson ( Journ . 
Amer. Assoc., May 1913), has the formula C 40 H 56 O 16 + 3H 2 O, is in needles or rhombic 
plates; m.p. 158-165°, or anhydrous 178-179°; a 4 per cent, solution in alcohol 
rotates [a] D = -f-3T6°. Concentrated sulphuric acid produces a green colour. 
Hefter and F. Saches ( Biochem. Zeitsch., 1912), from Strophanthus hispidus and 
Strophanthus kombe, have isolated amorphous strophantin, by taking up the residue 
from an alcohol extract by water, clarifying by lead acetate, filtering, freeing the filtrate 
from excess of lead, and evaporating down with calcium carbonate in excess to a 
syrup. The calcium carbonate was then filtered off, and an excess of ammonium 
sulphate added. The glucoside is precipitated, and purified by several times dis¬ 
solving in alcohol and precipitating by ether ; the glucoside from hispidus had the 
rotation [«]d+ 13-9°, from the kombe [a] D -|-ll-87 0 , but on hydrolysis they both gave 
the same strophanthidin, with a rotation [a] D of about 41°. 
The same authors isolated a crystalline glucoside, yielding a strophanthidin on 
hydrolysis which has a slight haemolytic action. 
All the above give a green colour with concentrated sulphuric acid. 
Ernst Gieburg (Ber., 1913) has separated from the seeds of Strophanthus gratus a 
saponin (G 21 H 34 O 10 ) 4 . It is said to be contained in the different varieties of Stroph¬ 
anthus up to 0-2 per cent. The saponin was obtained by operating on the mother- 
liquors in the manufacture of ( 7 -strophanthin; from these liquors, made fat-free and 
neutral by hydrochloric acid, the saponin was purified ultimately by solution in 
isobutylic acid and precipitation by ether. On hydrolysis it yields dextrose and 
strophanthigenin, (C 12 H 18 0 2 ) 2 3iH 2 0, white needles, m.p. 294°. 
(/-Strophanthic acid and strophanthigenin give various colour reactions. An alco¬ 
holic solution of benzaldehyde mixed with a dilute alcoholic solution of either of the 
substances gives a bright red colour with sulphuric acid. A saturated alcoholic 
solution of rhamnose with a trace of the substance produces a permanent cherry-red 
colour. 
Fromme’s method of estimating strophantin appears to be the best. 7 grms. 
of seeds are crushed and boiled for an hour with 70 grms. of absolute alcohol; 
on cooling, any loss of weight is made good by the further addition of alcohol. The 
liquid is now filtered, and 50-5 grms., equal to 5 grms. of the seeds, are freed from the 
solvent by evaporation. This residue is treated with petroleum and again filtered 
The insoluble portion contains the strophantin. This is boiled with 5 to 8 c.c. of water, 
treated with a little lead acetate solution and about 0-2 grm. kieselguhr, and filtered 
into a 100 -c.c. flask, the filter being well washed with small quantities of boiling water. 
The filtrate is now acidified by 5 drops of hydrochloric acid, and boiled for two hours 
1 Husemann, Archivf. exper. Path. u. Pharmakol., v. 228, 1876. 
2 Digitoxin (see ante, p. 442) belongs to this group. 
