THE INFLUENCE OF CHEMICAL CONSTITUTION ON THE LIPOLYTIC 
HYDROLYSIS OF ETHEREAL SALTS. 
Several years ago it was shown by Loevenhart and myself a that . 
active extracts of the pancreas and liver of the hog have the power of 
hydrolyzing various ethereal salts. In this connection it occurred to 
us to undertake a comparative study of the hydrolysis of various 
ethereal salts by lipase with the view of determining, if possible, the 
influence of their chemical constitution on the rate of the lipolytic 
hydrolysis. On account of the lack of material in the way of pure 
esters, however, and for other reasons, it was possible at the time to 
make only a few observations on the rate of hydrolysis of the eth\T 
esters of formic, acetic, propionic, and butyric acids. These, however, 
were sufficient to indicate that, leaving ethyl formate out of considera- 
tion, the rate of hydrolysis of ethereal salts by both pancreatic and 
hepatic lipase increases with increase in molecular weight of the 
ethereal salt and with increase in molecular complexity of the acid 
radical thereof. As originally carried out, however, our experiments 
were open to the objection that neither the ferment nor the ethereal 
salt was entirely in solution. 
With the view of remedying this experimental defect in the method, 
these experiments have been repeated, using perfectly clear solutions 
of liver lipase and aqueous solutions of the ethereal salts containing 
equivalent quantities of the various esters employed. The very spar- 
ing solubility of many of the ethereal salts in water has rendered it 
necessary to work with very dilute solutions of these substances, 
thereby greatly increasing the possibility of experimental error. Up 
to this time this has been the chief experimental difficulty encountered, 
but it is by no means the only one. The results herein presented are 
therefore given tentatively in the hope that the method of investiga- 
tion may be still further improved upon. With the exception of the 
work of Fischer , * 6 Armstrong, c and others on the selective action of 
certain enzymes on certain glucosides, and of the work of Fischer and 
Abderhalden^ on the conduct of various polypeptides toward the pan- 
creatic ferment, these results are of interest as being the first attempt 
a Am. Chem. Jour. XXIV, 491-525. 
& Berichte der deutschen chemischen Gesellschaft, 1894, pp. 1429, 2071, 2985, 3479. 
c Proe. Physiol. Soc., 1905, iv; J. Physiol., 33. 
Sitzungsber, K, Akad. Wiss. Berlin, 1905, 290-300, 
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