DESOXYCHOLIC ACID. 403 



dissolves in water with difficulty and is also relatively difficultly soluble 

 in alcohol. It has an intensely bitter taste and gives the MYLIUS iodine 

 reaction for cholic acid, and also the color reaction of cholic acid with 

 hydrochloric acid. The specific rotation is (a) D = +48.87 (VAHLEN). 

 The barium salt which crystallizes from the hot alcoholic solution as 

 spherical aggregations of radial needles is more difficultly soluble in 

 water than the corresponding cholate. 



Desoxycholic Acid, C^H^O^ is the name given by MYLIUS to a 

 cholic acid isolated by him from putrid ox-bile, and which is formed from 

 the cholic acid (on the putrefaction of the bile) by reduction. This last 

 is still veiy improbable, and the investigations of EKBOM do not support 

 such an assumption. On using perfectly pure cholic acid he was able 

 to regain it almost quantitatively after the action of metallic sodium on 

 the alcoholic solution of the acid or of zinc and alkali. By treatment with 

 zinc and glacial acetic acid a reaction took place, but the product was a 

 mixture of mono- and diacetyl derivatives. The observation of PREGL 

 that desoxycholic acid, like choleic acid, yields dehydrocholeic acid and 

 cholanic acid as oxidation products, makes the formation of desoxycholic 

 acid from cholic acid by reduction very improbable. The conclusion 

 of LATSCHINOFF that both choleic and desoxycholic acids are identi- 

 cal, is not to be accepted on account of the different properties of 

 the two acids, and what is more probable is that we have two different 

 acids which are probably isomeric with each other. Both acids can also 

 be detected in perfectly fresh ox-bile as shown by LANGHELD, and also 

 by HAMMARSTEN. 1 According to PREGL and to HAMMARSTEN, desoxy- 

 cholic acid is a preformed acid of the fresh bile. 



The acid crystallizes from glacial acetic acid in needles with 1 mole- 

 cule acetic acid, having a melting-point of 144-145. The melting-point 

 of the acid crystallized from alcohol-ether is 135-1 55 ; 2 and for the 

 anhydrous acid or crystallized from acetone it is 172173. It is soluble 

 with difficulty in water, more readily soluble in alcohol, but somewhat 

 less soluble in glacial acetic acid than choleic acid. It has an intensely 

 bitter taste. The acid does not give a blue iodine compound, and no 

 color reaction with hydrochloric acid. Its barium salt is soluble with 

 difficulty in cold water, but dissolves in boiling alcohol and crys- 

 tallizes on cooling. 



The cholic acids are best prepared from ox bile, which is boiled for 

 24 hours with 5-10-per cent caustic soda. The crude acid is precipitated 



1 Mylius, Ber. d d. chem. Gesellsch., 19 and 20; Ekbom, Zeitschr. f. physiol. Chem., 

 50; Pregl, Wien. Sitz.-Ber., Ill Math. Naturw. Kl., 9102; Latschinoff, Ber. d. d. 

 chem. Gesellsch., 20; Langheld, ibid., 41; Hammarsten, unpublished investigations. 



2 See Pregl, I.e. 



