448 THE LIVER. 



LiFSCHUTz's 1 Reaction. Dissolve a few milligrams of cholesterin 

 in 2-3 cc. glacial acetic acid, add a little benzoylsuperoxide thereto, and 

 boil once or twice. On adding 4 drops concentrated sulphuric acid to 

 the cooled solution and shaking, a pure green coloration is obtained, 

 which changes immediately into blue or with violet-red as an intermediary 

 color. An absorption-band is formed between C and d, and a broad band 

 at D. In this reaction an oxidation of the cholesterin occurs, and LIF- 

 SCHUTZ 2 therefore uses the glacial acetic acid-sulphuric acid reaction 

 (color and spectrum) for the detection of oxidation products of choles- 

 terin in blood and tissues. 



Pure, dry cholesterin when fused in a test-tube over a low flame with two or 

 three drops of propionic anhydride yields a mass which on cooling is first violet, 

 then blue, green, orange, carmine-red, and finally copper-red. It is best to re-fuse 

 the mass on a glass rod and then to observe the rod on cooling, holding it against 

 a dark background (OBERMULLER). S 



SCHIIT'S Reaction. If a little cholesterin is placed in a porcelain dish with 

 the addition of a few drops of a mixture of 2 or 3 vols. of concentrated hydrochloric 

 acid or sulphuric acid and 1 vol. of a rather dilute solution of ferric chloride, and 

 carefully evaporated to dryness over a small flame, a reddish-violet residue is 

 first obtained and then a bluish-violet. 



If a small quantity of cholesterin is evaporated to dryness with a drop of 

 concentrated nitric acid, one obtains a yellow spot which becomes deep orange-red 

 with ammonia or caustic soda (not a characteristic reaction). 



Cholesterin combines with saponin (WINDAUS, YAGI) and when a solution 

 of cholesterin in boiling 95 per cent alcohol is treated with a warm 1 per cent 

 solution of digitonin in 90 per cent alcohol, a precipitate of digitonin-cholesteride 

 is obtained. If the amount of the washed and dried digitonin-cholesteride is 

 multiplied by 0.25 the quantity of cholesterin is obtained (WINDAUS 4 ). The 

 cholesterin esters are not precipitated by digitonin. 



Koprosterin is the name given by BONDZYNSKI to the cholesterin which was 

 isolated by him from human feces, although it was prepared earlier by FLINT 

 and designated as stercorin. It dissolves in cold, absolute alcohol and very readily 

 in ether, chloroform, and benzene. It crystallizes in fine needles which melt at 

 95-96 C. (89-90 according to HAUSMANN), and is dextrorotatory () D = +24. 

 It gives the same color reactions as cholesterin, with the exception that it does 

 not give a reaction with propionic anhydride. According to BONDZYNSKI and 

 HUMNICKI it is a dihydrocholesterin, with the formula CarH^O, which is formed 

 in the human intestine by the reduction of ordinary cholesterin. According to 

 KUSUMOTO as well as DOREE and GARDNER, koprosterin also occurs in the intes- 

 tine of dogs. The koprosterin prepared by H. FISCHER from human feces seems 

 to be identical with that prepared by BONDZYNSKI. It is remarkable that BOEHM 5 



1 Ber. d. d. chem. Gesellsch., 41. 



2 Zeitschr. f. physiol. Chem., 50, 53, 58, and Ber. d. d. chem. Gesellsch., 41. 

 8 Zeitschr. f . physiol. Chem., 15. 



4 Windaus, Zeitschr. f. physiol. Chem., 65; Yagi, Arch. f. exp. Path. u. Pharm., 64. 



6 Bondzynski, Ber. d. deutsch. chem. Gesellsch., 29; Bondzynski and Humnicki, 

 Zeitschr. f. physiol. Chem., 22; Flint, ibid., 23, and Amer. Journ. Med. Sciences, 

 1862; Miiller, Zeitschr. f. physiol. Chem., 29; Hausmann, Hofmeister's Beitrage, 6; 

 Kusumoto, Bioch. Zeitschr., 14; Dore"e and Gardner, Proc. Roy. Soc. London, 80, 

 Ser. B.; H. Fischer, Zeitschr. f. physiol. Chem., 73; Boehm, Bioch. Zeitschr., 33. 



