46 SCIENCE PROGRESS 



Gornall from the seeds of Gynocardia odorata, an Indian plant, 

 which belongs to the natural order Bixineae and was long 

 supposed to be the source of chaulmugra oil : the production 

 of prussic acid both by the leaves and seed of this plant had 

 been previously observed by Greshoff and by Desprez. 1 The 

 glucoside was subsequently investigated by Power and Lees, 2 

 who showed that it differed from all the known cyanogenetic 

 glucosides in being decomposed by acids only with great 

 difficulty. Gynocardin is, however, readily decomposed by 

 a specific enzyme, gynocardase, occurring in the same seeds, 

 yielding one molecule each of prussic acid, dextro-glucose, and 

 a very unstable third product whose nature has not yet been 

 ascertained. 



Lotusin. — This substance was isolated by Dunstan and 

 Henry 3 from the annual leguminous plant Lotus arabicus, which 

 grows along the valley of the Nile, where it is known by the 

 vernacular name " khuther." The Arabs have long known that 

 "khuther" is poisonous in the early stages of its growth, and 

 that it becomes innocuous and, indeed, a useful and nutritive 

 fodder as it matures. The plant was a great source of trouble 

 to the Anglo-Egyptian armies during the first and second 

 Sudanese wars, owing to the fact that many of the transport 

 animals were poisoned by eating it. 



This led eventually to its investigation, and to the discovery 

 that it contained a glucoside, lotusin, which, under the influence 

 of an enzyme, lotasc, also present in the plant, underwent 

 decomposition yielding prussic acid as one product. The same 

 decomposition occurs when lotusin is treated with hot dilute 

 hydrochloric acid, and the reaction which takes place may be 

 represented by the following equation : 



C 28 H 3I 16 N + 2H 2 = C, 5 H 1( A + HCN + 2C B H 12 6 



Lotusin. Lotoflavin. Prussic acid. Dextro-glucose. 



The first of these decomposition products — viz. lotoflavin — 

 is of considerable interest, since it is a yellow dye belonging 

 to the same group as quercetin, the dyeing principle contained 

 in the well-known dyewood obtained from Quercus tindoria. 



Further investigation of the plant confirmed the accuracy 

 of the Arab belief that " khuther " is only poisonous in the early 



1 Jouck, loc. cit. 



2 Power and Lees, Jonrn. Chan. Soc. 1905, 87, 349. 



3 Phil. Trans. 1901, B. 194, 515. 



