THE CHEMISTRY OF CHOLESTERINE 97 



The Oxidation of Cholesterine 



With chromic acid, permanganate, etc., under ordinary con- 

 ditions, no breaking down of the cholesterine molecule takes 

 place, but various neutral and acid bodies are formed still 

 containing the same number of carbon atoms as the original 

 substance. Mauthner and Suida accordingly (1903) investigated 

 the action of strong nitric acid and of concentrated perman- 

 ganate solution both in the cold and at ioo°. In each case 

 they obtained among other products two homologous acids 

 C 13 H 18 8 and C 12 H 10 O 8 , of which the last appears to be the end 

 product of the action, since further oxidation led to its recovery 

 unchanged. They are both tetrabasic. Their calcium salts 

 contain eight molecules of water of crystallisation, and though 

 soluble in cold water are thrown out of solution on heating. 

 By the loss of a molecule of water or carbon dioxide the acids 

 yield new compounds which, according to Mauthner and Suida, 

 would greatly simplify the work on cholesterine. The authors, 

 however, were not able to connect these products with any 

 known substances, and so far as we know, have not continued 

 their investigations on the subject. Windaus also in 1903 found 

 that by prolonged boiling with highly concentrated nitric acid 

 acetic acid was formed in some quantity, together with a small 

 amount of dinitro-isopropane (CH 3 ) 2 . C . (N0 2 )] — results which 

 led him to infer the presence of the methyl and isopropyl 

 groups in cholesterine. 



The above results represent, we believe, the only resolu- 

 tions of the cholesterine molecule so far achieved. Ordinary 

 oxidising agents give rise to a number of twenty-seven carbon 

 derivatives, important from a chemical standpoint, but whose 

 study is somewhat difficult as they are described in the litera- 

 ture under varying names, and their empirical formulae, differing 

 only by one or two atoms of oxygen and hydrogen, give no 

 clue to their connection with cholesterine and with one another. 

 The following structural formulae (after Windaus), even if they 

 are not accurate representations of the molecular portions 

 considered, will be found most useful in bringing out these 

 relations. It will be noticed that chromic acid and perman- 

 ganate seem to attack first the unsaturated side chain of the 

 cholesterine, which then undergoes condensation with the pro- 

 duction of a new ring, and that, starting from cholesterine, 



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