THE CHOLINE GROUP. 
531 
§ 7 01 -] 
All these bodies can be prepared from choline ; their relationship to 
choline can be readily gathered from the following structural formulae :— 
ch 2 oh 
ch 2 
N(CH 3 ) 3 .OH 
Choline. 
ch 2 
II 
CH 
N(CH 3 ) 3 .OH 
Neurine. 
co 2 h 
ch 2 
I 
N(CH 3 ) 3 .OH 
Betaine. 
ch 2 oh 
CHOH 
N(CH 3 ) 3 .OH 
Muscarine. 
Choline is a syrup with an alkaline reaction. On boiling with water, it 
decomposes into glycol and trimethylamine. It gives, when oxidised, 
muscarine. It forms salts. The hydrochloride is soluble in water and 
absolute alcohol; neurine hydrochloride and betaine hydrochloride are 
but little soluble in absolute alcohol, therefore this property can be 
utilised for their separation from choline. The platinochloride is in¬ 
soluble in absolute alcohol; it melts at 225° with effervescence, and 
contains 3T6 per cent, of platinum. The mercurochloride is soluble 
with difficulty even in hot water. The aurochloride (Au = 44-5 per cent.) 
is crystalline, and with difficulty soluble in cold water, but is soluble 
in hot water and in alcohol; melting-point 264°, with decomposition. 
Choline is only poisonous in large doses. 
§ 701. Neurine (Trimethyl-vinyl-ammonium hydrate), C 2 H 3 N(CH 3 ) 3 
OH.—Neurine is one of the products of decomposition of choline. It is 
poisonous, and has been separated by Brieger and others from decom¬ 
posing animal matters. In Brieger’s process, neurine, if present, will 
be for the most part in the mercuric chloride precipitate, and some 
portion will also be in the filtrate. The mercury precipitate is decom¬ 
posed by SH 2 , the mercury sulphide filtered off, and the filtrate, con¬ 
centrated, treated with absolute alcohol and then precipitated by 
platinum chloride. It is usually accompanied by choline ; the platino¬ 
chloride of choline is readily soluble in water, neurine platinochloride 
is soluble with difficulty ; this property is taken advantage of, and the 
platinochloride crystallised from water until pure. Neurine has a 
strong alkaline reaction. 
Neurine chloride, C 5 H 12 N.C1, crystallises in fine needles. The platino¬ 
chloride, (C 5 H 12 NCl) 2 PtCl 4 (Pt = 33-6 per cent.), crystallises in octahedra. 
The salt is soluble with difficulty in hot water. 
The aurochloride, C 5 H 12 NC1AuC1 3 (Au = 46-37 per cent.), forms flat 
prisms, which, according to Brieger, are soluble with difficulty in hot 
water. 
Neurine picrate, C 5 H 12 NC 6 H 2 0 7 N 3 , melting-point 263°, soluble in 
91-6 parts cold water, readily in hot alcohol. 
Neurine is intensely poisonous, the symptoms being similar to those 
produced by muscarine. 
