PICROTOXIN. 
477 
§§ 608, 609.] 
Picrotin (C 15 H 18 0 7 ) separates out on cooling the filtrate from the 
bromopicrotoxinin ; it may be purified by washing with small quantities 
of hot chloroform and recrystallising from water. It forms small 
needles or rhombic prisms melting at 248°-250° ; it is soluble in absolute 
alcohol or acetic acid, and only slightly in ether, chloroform, and benzene. 
It reduces Fehling’s solution and has [u] D =* —64-70° ; it forms a number 
of derivatives, such as benzoylpicrotin (C 15 H 17 0 7 Bz), crystallising from 
absolute alcohol in colourless crystals—m.p. 236° ; acetylpicrotin 
(C 15 H 17 0 7 Ac), m.p. 244°-245° ; anhydrodiacetylpicrotin (C 15 H 14 0 6 Ac 2 ) ; 
and diacetylpicrotin (C 15 H 16 0 7 Ac 2 ), an oil. 1 
Paul Horrmann ( Annalen , 1916) considers picrotoxinin and picrotin 
dilactones. Excess of aqueous alkali ruptures both lactone rings into 
picrotoxinin dicarboxylic acids, C 15 H 20 O 8 , decomposing at 163°, [a] D 
17-5+31-27° in alcohol; and picrotin dicarboxylic acid, C 15 H 22 0 9 , de¬ 
composing at 271°, [a] D 17-5 + 61-53° in alcohol. 
Picrotin on oxidation gives only one acid, C 15 H 20 O 8 ; this acid 
is the a acid. 
§ 608. Tests for Picrotoxin. —(1) The fact that one of the decom¬ 
position products of picrotoxin is acetone may be utilised as a test. A 
few milligrammes of the supposed picrotoxin are placed in a very small 
flask, 5 to 10 c.c. of N. soda solution added, and distilled. The distillate 
is alkalised by normal soda, and iodine solution added carefully until 
there is a permanent very slight yellow colour. Should acetone be 
present, an immediate very fine precipitate results. The precipitate is 
separated by a micro-filter and dissolved in a c.c. of warm 90 per cent, 
alcohol, and the solution allowed to evaporate at ordinary temperature. 
In this way characteristic iodoform crystals will be obtained. 
(2) If pure, dry picrotoxin be mixed with three times its volume of 
potassic nitrate, a drop of strong sulphuric acid added, and then super¬ 
saturated with soda lye, a brick-red colour results. Colchicin and some 
other aromatic bodies give a similar reaction. 
(3) Picrotoxin boiled with vanilla hydrochloric acid gives after a few 
minutes a green colour. 
(4) On heating an ethereal extract containing picrotoxin in a sublim¬ 
ing cell there is a sublimate at about 215°, of drops. These drops give 
crystals on being treated with hydrochloric acid ; according to 0. Tun- 
mann ( Apoth . Zeit., 1917), it is preferable to use 5 per cent, ferric chloride 
solution. The sublimate is treated with a drop of this solution and 
heated under a cover-glass until bubbles appear ; on cooling, typical pen¬ 
tagonal tablets can be observed. A drop of bromine water added to a 
sublimate and heated produces on cooling prisms of bromo-picrotoxinin. 
§ 609. Fatal Dose. —Yossler killed a cat in two hours with a dose of 
•12 grm. (1-8 grain) ; and another cat, with the same dose, died in 45 
1 R. J. Meyer and P. Benger, Ber., xxxi., 1898. 
