— 134 — 
Piperonal, also called heliotropin: 
fO- 
*--8 Hg O3 — Cg Hg 
0-^ 
CHO 
is methylene ether of protocatechuic aldehyde. It is found regularly 
in oil of spiraea, i. e. the oil of Spiraea Uimaria, and in many kinds 
of vanilla. 
Piperonal is produced on a large scale by treating piperic acid, 
or — and now almost exclusively — safrol and isosafrol with oxi- 
dising agents. It forms inch-long lustrous crystals (from water), is so- 
luble in 500 to 600 parts cold water, readily in alcohol, in every 
proportion in ether and hot alcohol. The melting point lies at 37°, 
the boiling point at 263°. It behaves generally as benzaldehyde. It 
is a remarkable fact that it does not give the characteristic reduction 
of salts of copper, gold, etc. by aldehydes. On oxidation it forms 
the corresponding piperonylic acid. 
Piperonal plays an important part in the perfumery industry. It 
possesses a penetrating, coumarin-like odour, which strongly reminds of 
the actual perfume of the heliotrope flower. It is used in the manu- 
facture of extraits, sachets, and soaps. When exposed to the sun, 
the crystals acquire a yellowish -brown colour, and lose the perfume 
completely. 
According to the experiments made by Dr. Ricardo Frignani 
(comp. New York Medical Record), heliotropin possesses antipyretic 
and antiseptic properties. The antipyretic action is not very energetic, 
but in many cases sufficient. It is best administered in doses of 
15 grains 3 to 4 times daily, but larger doses are also tolerated quite 
well. Its antiseptic action is stronger, and as it is harmless even in 
doses of Y2 I drachm, it deserves a high place among similar remedies. 
According to O. Wimmer, "Further experimental examinations re- 
specting piperonal. Thesis (Liebreich) Berlin", piperonal checks the 
action of pepsin and pancreas, the fermentation of lactic acid, putres- 
cence, but not the action of yeast. It reduces the temperature of 
animals in a normal or feverish condition (also clinical observation). 
More detailed examinations of the behaviour of piperonal in the 
animal body have been made by Dr. A. Heffter. In the organism 
of the rabbit (4,0 g were injected), piperonal was converted into the 
allied piperonylic acid, which could be precipitated from the alcoholic 
extract of the urine be means of hydrochloric acid. It was remark- 
able that here no combination had taken place with glycocoll, as this 
is the case with all aromatic monocarboxylic acids, if they contain not 
more than one hydroxyl-group. 
