The Nature and Origin of the Poison of Lotus arabicus. 377 



action on amygdalin, the glucoside of bitter almonds. Lotase is much 

 more readily injured and deprived of its hydrolytic power than 

 emulsin. On this account it is difficult to isolate in the solid state. 

 Its power is not only rapidly abolished by heat, but is also gradually 

 destroyed by contact with alcohol or glycerine. Besides lotase, the 

 plant contains an amylolytic and a proteolytic enzyme. 



Constitution of Lotoflavin and Lotusin, 



Having regard to its reactions and especially to the production,, 

 by the action of fused alkali, of /3-resorcylic acid and phloroglucin,, 

 the authors conclude that lotoflavin should be represented by tha 

 formula : 



OH 



OH CO 



which is that of a compound belonging to the same class, of phenylated 

 pheno-y-pyrones, as its isomerides luteolin and fisetin". The peculiarity 

 shown by lotoflavin of containing four hydroxyl groups, but furnishing 

 only a £nmethyl ether, is accounted for by one of the hydroxyl groups 

 being in the ortho position to a carbonyl group. 



The reactions of lotusin are best represented by the formula : 



O OH 



CN 



e n H 21 o 10 — ch— o r Y / 0H 



OH CO 



which is that of a lotoflavin ether of maltose-cyanhydrin. 



This formula satisfactorily accounts for the partial hydrolysis of the 

 glucoside by alkalis giving lotusinic acid and ammonia, and for the 

 decomposition of the substance by acids giving lotoflavin and maltose- 

 carboxylic acid which is immediately decomposed into dextrose and 

 heptogluconic acid. It also accounts for the hydrolysis of lotusin, 

 by acids, into lotoflavin and maltose, which is further changed to 

 dextrose. 



In order to definitely localise the position of the cyanogen group in 

 lotusin, the behaviour of several cyanhydrins of known constitution 

 have been examined with reference to the question as to whether 

 they would furnish hydrocyanic acid when acted on by dilute hydro- 

 chloric acid. It was found that mandelic nitrile, lsevulose cyanhydrin 

 and pentacetyl gluconitrile, in which the cyanogen group is known to 

 occupy a position similar to that assumed for it in the formula sug- 



2 D 2 



