. 



FAT-SPLITTING ENZYMES 173 



of esters both of mono-basic and of di-basic acids. They 

 proposed a provisional hypothesis, according to which the 

 hydrolysis of ethereal salts by lipase involves the direct 

 association of the enzyme with the carboxyl group. Hydro- 

 lysis appears to take place more readily when OH groups 



are absent ; thus ethyl succinate, | , is more 



CR^0 2 C^i 5 



CHOHC0 2 C2H 5 



readily broken up than ethyl tartrate, | , while 



ethyl malate, | , occupies an intermediate 



position. 



They concluded that the difference between animal and 

 vegetable lipase is one of degree, and if sufficient enzyme 

 is used almost all esters are more or less attacked. 



Kastel and Loevenhart made use of animal lipase in the 

 following way : they macerated fresh pancreas with coarse 

 sand, extracted the enzyme with water or glycerine, 1 c.c. 

 of the extract from either 10, 20 or 50 grams of tissue 

 was diluted to 100 c.c. and allowed to act for forty minutes 

 on a mixture of 4 c.c. of water, O'Ol c.c. toluene, and 0*25 c.c. 

 of ethyl butyrate at 40C., the mixture being afterwards 

 titrated with ^ potash solution. They found that the 

 enzyme was destroyed at a temperature of 60 to 70 C., 

 and that most antiseptics had an injurious effect on it, 

 especially sodium fluoride and mineral acids. 



By titrating the solutions at definite intervals of time they 

 obtained results which led them to the following conclusions : 



