CXXXVI.—The absorption spectra of cinchonine, quinine, and their isomerides

Abstract

THE investigation described in this paper was undertaken originally with the object of ascertaining whether the absorption spectra of cinchonine and its isomerides a-, p-, and allocinchonine differ from one another in such a way as to imply differences,in the structure of these alkaloids, or are identical, as one would expect them to be if the alkaloids possessed the same structure. We found the spectra to be indistinguishable, but, for reasons to be explained hereafter, it is impossible to infer from their identity that the alkaloids in question are stereoisomerides. The investigation, however, has yielded results of considerable interest in other directions. The absorption spectra of cinchonine and quinine were first examined by Hartley (Phil. Trans., 1885, 175, 471)) and afterwards by ourselves (Trans, 1903, 83, 605). In the course of the present investigation we had occasion to

Chinin, ein legendäres Alkaloid

“…Chinin zeigt zwei sehr starke UV‐Absorptionen (Abbildung ) zwischen 210 und 240 nm mit ε‐Werten bis zu 60.000 cm 2 × mmol –1 . Zusätzlich findet man zwei schwache Banden bei 275 nm und 340 nm . Letztere sind wohl bedingt durch die auxochrome Wirkung der Methoxygruppe am 10 π‐Elektronensystem des Chinolins.…”

THE INHIBITION OF THE PHOTOCHEMICAL DECOMPOSITION OF HYDROGEN PEROXIDE SOLUTIONS. I1

“…Assuming, therefore, that the absorption of quinine salicylate is approximately the sum of the absorptions of quinine and salicylic acid we should expect continuous absorption below 3400 A. 75 The salicylic acid should eliminate the diactinic portion of the region of wave length noted under quinine hydrochloride. There is no evidence in the case of either quinine salt of any decomposition during illumination.…”