Scientific Proceedings. 



145 



100 (243) 



Alkaloidal compounds of mucoids, nucleoproteins and 

 other proteins. 



By WALTER H. EDDY and WILLIAM J. GlES. 



\_From the Laboratory of Biological Chemistry of Columbia Uni- 

 versity, at the College of Physicians and Surgeons?^ 



In continuation of our studies of protein compounds we have 

 observed that nucleoprotein, mucoid, caseinogen and alkali albumi- 

 nate form water-soluble products with alkaloids. By intimately 

 mixing samples of the purified moist protein and the pure alkaloid, 

 especially with the latter in considerable excess, soluble products 

 are formed, which may be precipitated by alcohol or alcohol-ether, 

 and which, after purification and drying, readily dissolve in water. 

 Such aqueous solutions are neutral to litmus, and the proteins may 

 be readily precipitated from the solutions by slightly acidifying 

 them. 



Many such protein-alkaloid products have been made. The 

 purest thus far obtained was prepared from mucoid and strychnin 

 by the following general process : After thoroughly mixing moist 

 mucoid with an excess of strychnin, the viscid mass was extracted 

 several times with water and the centrifuged extracts were filtered 

 and combined. The filtrates were faintly opalescent and neutral 

 to litmus. They were evaporated nearly to dryness at 40 0 C. in 

 shallow dishes in the presence of toluol, which was frequently 

 renewed in small amounts. The protein-alkaloid product was pre- 

 cipitated from the concentrated solution by alcohol-ether added in 

 large excess. The resultant precipitate was dissolved in water and 

 the solution subjected to the previous evaporation process. The 

 abundant dry residue thus obtained was finely pulverized and re- 

 peatedly extracted with large proportions of chloroform until no 

 more strychnin could be removed, even after exposure to fresh 

 chloroform for several days. 



The resultant product possessed a very bitter taste, gave the 

 common color reactions for protein, responded sharply to the 

 oxidation test (with sulfuric acid and dichromate) for strychnin and 

 dissolved readily in water, forming a clear solution. The aqueous 



