640 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



laevorotatory. CINCHONINE separate sin lustrous prisms or needle 5 

 which are nearly insoluble in water, and does not give the thalleio- 

 quin test, but forms a white precipitate upon the addition of dilute 

 sulphuric acid, bromine water and ammonia. CINCHONIDINE crys- 

 tallizes in prisms and resembles cinchonine in many of its properties. 

 Its solutions, however, are Isevorotatory, while those of cinchonine 

 are dextrorotatory. 



The other important alkaloids of Cinchona which have been 

 separated are: Quinamine, hydroquinine, hydroquinidine, hydro- 

 cinchonidine and homocinchonidine. Of the other alkaloids which 

 have been isolated the following may be mentioned : Conquinamine, 

 paranine, paracine and quinamidine. Among the other constituents 

 of Cinchona are : Kinic acid from 5 to 9 per cent, which forms color- 

 less rhombic prisms and yields a sublimate consisting of golden crys- 

 tals of kinone (quinone) on treatment with manganese peroxide and 

 sulphuric acid; kinovin (quinovin) an amorphous, bitter glucoside, 

 to the amount of 0.11 to 1.74 per cent; cinchotannic acid from 2 to 4 

 per cent, which decomposes into the nearly insoluble cinchona red, 

 occurring in red barks to the extent of 10 per cent; considerable 

 starch; calcium oxalate in the form of sphenoidal microcrystals; 

 and ash about 3 per cent. The red color in cinchona bark is due to 

 an oxydase similar to that which causes the darkening of fruits when 

 cut. If the fresh bark is heated in boiling water for 30 minutes and 

 then dried it does not become red. 



Quinine Sulphate [(CkoH^A^.^SOa-r-THzO]. 



The alkaloid quinine (C2oH 2 4N 2 O2) is the methoxy-derivative 

 of cinchonine and separates in anhydrous crystals from hot aqueous 

 solutions. If the hot solution, in dilute alcohol, is kept for some time 

 at 30 C., then on cooling long silky needles form. There is another 

 modification, occurring as a flaky powder and containing three 

 molecules of water of crystallization (C2oH24N2O2+3H2O), which is 

 official. Some authors consider, however, that there is only one 

 molecule of water of crystallization in this hydrous salt. 1 The 

 hydrous salt has a M. P. of 57 while the anhydrous crystals melt at 

 175. Quinine is a strong base, forming, with acids, basic and neutral 

 salts. The neutral sulphate is largely used and is here considered. 



There are several modifications of quinine sulphate: (1) The 

 neutral sulphate containing eight molecules of water of crystalliza- 

 tion [(C2oH24N2O2)2.H2S04+8H20], is obtained upon neutralizing 

 the base with sulphuric acid and crystallizing from hot water. (2) 

 Upon exposing the former over sulphuric acid it loses six molecules 

 1 O. A. Oesterle, Grundriss der Pharmakochemie. 



