166 



REPORT — 1903. 



The Absorption SjiecAra of Laudanine and Laudanosine in Relation to 

 their Co7istitutionJ By James J. Dobbie, Z).»Vc., 21. A., a?icZ Alexander 

 Lauder, B.Sc. 



It has been shown that alkaloids which only differ from one another 

 in minor details of structure give similar absorption curves, whilst those 

 which differ widely in structure give coi'respondingly different series of 

 spectra. So far, no case has yet been encountered in which two substances 



Fig. 2;5.— Laudauosine, 



C,,H,,O^N. 



{In alcoholic solution.) 



*^i-ifle of vsfiUtttitiii'fri'qiii'iHif^. 



Fig. 24. — Laudanine, 

 {Ill alcoholic solidion.) 



Smli' iif oscillntioii-firqiieinifS. 



■~ A 



i o 



~ rH 



t 



I- 



known to differ substantially in structui'e give an identical or nearly iden- 

 tical series of spectra. 



This principle finds an interesting application in the case of laudanine, 

 C.2nH2,p,0<N, and laudanosine, C.^iH.jjOjN, two rare alkaloids separated 

 by Hesse - from opium. These differ from one another by CH.;, and since 

 the former contains three, and the latter four methoxyl groups, it has 

 been assumed that the substances are homologous, although the conversion 

 of laudanine into laudanosine has not yet been accorapli.shed. If this 

 view of their relation is correct, they should give practically identical 

 absorption curves, and this we have found to be actually the case, the 



' Cfiem. Soc. Trans., 1903, 83, 62G. 



= Anuulen, 1870, 77, 47; Sll2>^)l., 1872, 8, 261, 



1 



