THE CHEMISTRY OF THE MORPHINE 

 GROUP OF ALKALOIDS 



By H. E. WATT, D.Sc. (Dunelm.), F.I.C. 

 Scientific and Technical Department, Imperial Institute 



Up to the beginning of the nineteenth century it was not known 

 that basic substances could exist in plants, for it was not until 

 the year 1803 that Derosne isolated from opium an impure 

 crystalline substance (probably narcotine) which he named 

 " opium salt." He did not, however, carry his investigations 

 very far, since he ascribed such basic properties as he had 

 observed to an impurity arising from the alkali used in the 

 purification of the " salt," and was therefore quite unaware 

 of the important chemical properties which the new substance 

 possessed. Three years later Sertiirner l also obtained a 

 crystalline product in a pure state from opium, and recognised 

 that it exhibited undoubted basic properties. 



The latter substance — morphine — was the first of that large 

 and important class of compounds now known as alkaloids 

 to be definitely recognised, and was assigned the formula 

 C 17 H 19 3 N + H 2 by Laurent 2 ; it is present in opium to the 

 extent of 3 to 23 per cent. Owing to the labours of a 

 large number of chemists, whose energies were directed to 

 this special field of work, it soon became apparent that in 

 opium morphine was associated with several other alkaloids, 

 and of these, two bases, codeine and thebaine, now known to 

 be closely related to morphine, were subsequently isolated. 

 The former, discovered by Robiquet 3 in 1832, occurs in 

 proportions varying from o - 3 to 2 per cent., and its formula 

 was found by Gerhardt 4 to be C ls H 21 3 N + H 2 0, whilst 

 thebaine, of which opium contains 0*2 to 1 per cent., was 

 isolated three years later by Thiboumery, and, being thought 



1 Tromsdorjps Journ. d. Pharm. 13, i. 234. 3 Ann. chint, phys. (2), 51, 259. 



2 Journ. de pharmacie (3), 14, 302. * Ibid. (3), 7, 253. 



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