370 



Studies l\on Enzyme Action. XVIII. — Enzymes of the Emulsin 

 Type. (Ill) Linase and other Enzymes in Linacece. 

 By H. E. Armstrong, F.E.S., and J. Vargas Eyre, M.A., Ph.D. 



(Received April 3,— Eead May 16, 1912.) 

 [International Catalogue of Scientific Literature. 

 Author's title slip : — D. K. M. 

 Subject slips : — 



D 8014 Enzymes of the emulsin type — linase. 



D 8030 Variations of glucoside and enzyme in linseed. 



K <j120\ g n z „ meg j n Linaceae.l 



D 6525 J J J 



In No. XIII of these studies, communicated to the Society early in 1910, 

 a long series of observations was recorded from which the conclusion was 

 deduced that the glucoside extracted from the seeds of the wild variety of 

 Phaseolus lunatus and the enzyme associated with the glucoside both belong 

 to the /3-series, a conclusion not in harmony with that arrived at previously 

 by Dunstan, Henry and Auld.* 



The glucoside termed by Dunstan and Henry Phaseolunatin was first 

 isolated from young flax plants in 1891 by Jorissen and Hairs,t by whom it 

 was named IAnamarin. Jorissen had previously found that " emulsin " had 

 no action on the cyanophoric constituent of flax, though the glucoside was 

 readily attacked by the enzyme occurring in the seed. 



Jorissen's discovery was confirmed in 1903 by Dunstan, Henry and Auld. 

 The flax enzyme, according to their statement, has a range of activities 

 similar to that of almond-emulsin, readily hydrolysing amygdalin and salicin.j 

 There is nothing to show, however, that their conclusion was based on 

 quantitative determinations. On account of this statement and on various 

 other grounds, it appeared to us that it was desirable to study the " enzyme " 

 in flax more thoroughly : one reason in particular was our desire to discover 

 a material from which we could obtain the enzyme whenever necessary, for 

 assuming that the two plants yield the same enzyme, as linseed is so 

 easily procured, it obviously is a far more convenient source of the enzyme 

 than is Phaseolus lunatus, a seed which is no longer on sale in this country. 



* ' Eoy. Soc. Proc.,' 1906, B, vol. 78, p. 145 ; 1907, B, vol. 79, p. 315. 

 t ' Bull. Acad. Eoy. Belg.,' 1891, vol. 21, p. 529. 



\ It is asserted by Dunstan, Henry and Auld that — "In subsequent papers, Jorissen 

 stated that both Linv.m t'sitatissimvm and Linum perenne contain amygdalin in the leaves 

 and stems." This is incorrect. Jorissen speaks of " an amygdalin," not of actual 

 amygdalin, using the term in a generic sense as meaning a substance which behaves like 

 amygdalin on hydrolysis. 



