CHONDROITIN-SULPHURIC ACID. 523 



acid and glucosamine. This assumption does not seem to have sufficient 

 foundation. According to ORGLER and XEUBERG, chondrosin does not 

 give the orcin test nor does it yield furfurol. They claim that on 

 cleavage with baryta it yields, besides a carbohydrate complex which 

 has not been studied, an oxyamino-acid having the formula C 6 Hi 3 O 6 N 

 and also a hexosamine acid or tetraoxyaminocaproic acid. In opposition 

 to this S. FRANKEL l has found that the chondrosin gives the orcin as 

 well as the phloroglucin test with hydrochloric acid, and he has prepared 

 an acid with the formula C 6 H n NO 6 , which he calls aminoglucuronic 

 acid, which gives the above .tests and also reduces. 



Chondroitin-sulphuric acid appears as a white amorphous powder 

 which dissolves very easily in water, forming an acid solution and, when 

 sufficiently concentrated, a sticky liquid similar to a solution of gum 

 arabic. Nearly all of its salts are soluble in water. The neutralized solu- 

 tion is precipitated by stannous chloride, basic lead acetate, neutral ferric 

 chloride, and by alcohol in the presence of. a little neutral salt. The 

 solution, on the other hand, is not precipitated by acetic acid, tannic 

 acid, potassium ferrocyanide and acid, sugar of lead, mercuric chloride, 

 or silver nitrate. Acidified solutions of alkali chondroitin-sulphates 

 cause a precipitation when added to solutions of gelatin or proteid. 



The preparation of chondromucoid and its separation from chondroit in- 

 sulphuric acid can be accomplished after the method of C. MORNER, but for 

 details we refer to the original work. 



The pre-existing chondroitin-sulphuric acid, or that formed by the 

 decomposition of chondromucoid, is obtained by lixiviating the cartilage 

 with a 5-per cent caustic-alkali solution. The alkali albuminate formed 

 by the decomposition of the chondromucoid can be removed from the 

 solution by neutralization, then the peptone precipitated by tannic acid, 

 the excess of this acid removed with sugar of lead, and the lead removed 

 from the filtrate by H 2 S. If further purification is necessary, the acid is 

 precipitated with alcohol, the precipitate dissolved in water, this solu- 

 tion dialyzed and precipitated again with alcohol, this solution in water 

 and precipitation with alcohol being repeated a few times, and lastly 

 the acid is treated with alcohol and ether. 



SCHIMIEDEBERG prepared the acid from the septum narium of the pig 

 according to the following method: The finely divided cartilage is 

 first exposed to artificial peptic digestion, then carefully washed with 

 water and the insoluble residue treated with 2-3 per cent hydrochloric 

 acid. This cloudy liquid containing hydrochloric acid is precipitated with 

 alcohol (about one-quarter vol.) and the clear filtrate treated with absolute 

 alcohol and some ether. The precipitate, consisting chiefly of a com- 

 bination or a mixture of chondroitin-sulphuric acid and gelatin pep- 

 tone (peptochondrin), is first washed with alcohol and then with water. 



1 Orgler and Neuberg, Zeitschr. f. physiol. Chem., 37; Frankel, Annal. d. Chem. u. 

 Pharm., 351. 



