328 PRACTICAL ORGANIC AND BIO-CHEMISTRY 



Glycocholeic Acid. C 2< ,N 43 O 5 N or C 27 H 45 O 5 N. 



This acid accompanies glycocholic acid in bile. 



It is prepared as described under glycocholic acid. 



Glycocholeic acid crystallises in prisms or bunches of fine needles which 

 melt at 1 75-1 76. It has a bitter taste, is almost insoluble in cold and boiling 

 water, but is easily soluble in alcohol. 



Its alkaline salts are soluble in water, but not so easily as those of glyco- 

 cholic acid. They are precipitated by calcium, barium and magnesium salts. 

 The barium salt is precipitated as a sticky mass, but crystallises from water in 

 bunches of needles. 



It yields glycine and choleic acid on hydrolysis by acids or by alkalies. 



Glycocholeic acid is distinguished from glycocholic acid by melting-point, 

 rotation and insolubility, also by the insolubility of its barium salt, other- 

 wise it resembles glycocholic acid. 



Glycohyocholic Acids. 



Two acids, a-glycohyocholic acid and /?-glycohyocholic acid, have been 

 prepared from pig's bile. They differ slightly in properties from glycocholic 

 acid and have been seldom investigated. 



Fellinic Acid. C 23 H 40 O 3 . 



Fellinic acid, together with cholalic acid, has been obtained from human 

 bile. 



Chenocholic acid, C 27 H 44 O 4 , Ursocholeic acid, C l8 H 28 O 4 ? and Lithofellic 

 acid, C 20 H 36 O 4 , are other acids obtained from different biles. 



Taurocholic Acid. C 26 H 45 O 7 NS. 



C H^O CO Taurocholic acid accompanies glycocholic 



I acid in ox bile. It is present in fish bile and 



' | snake's bile. Dog's bile and the bile of car- 



,H 2 . SO 3 H. n j vora jo not contain glycocholic acid. In all 



cases it is present as the sodium salt. 



Preparation. 



Hammarsten gives the following preparation of taurocholic acid from cod's 

 bile and dog's bile. 



(a) From Cods Bile. 



The bile is precipitated with ferric chloride, the filtrate is treated with 

 sodium carbonate to remove iron, the solution from the ferric carbonate 

 is nearly neutralised and saturated with sodium chloride. The precipitate of 

 taurocholate is washed with saturated salt solution, dissolved in water and 

 again precipitated with salt. The taurocholate is dissolved in water and 

 separated from sodium chloride by repeated evaporation and solution in 

 alcohol. Taurocholic acid is obtained from the sodium salt by rubbing with 

 alcohol containing about 2 per cent, of sulphuric acid, shaking up, filter- 

 ing from sodium sulphate and adding ether. The flocculent precipitate is 

 separated, dissolved in absolute alcohol and again thrown down with ether. 

 The clear solution of the precipitate in alcohol is treated with a few drops of 

 water and then with ether till it is turbid. An amorphous precipitate, if 

 formed, is rapidly filtered off and more ether is added. The acid commences 

 to crystallise out after some time and when the amount ceases to increase 

 ether may be again added. This is continued until no further crystals are 

 obtained. 



