CHLOROPHYLLASE 233 



On the other hand, working with methyl alcohol and 

 chlorophyllase, it has been found possible to replace the phytyl 

 group by methyl, forming methylchlorophyllide, which is the 

 methyl analogue of ethylchlorophyllide or crystalline chloro- 

 phyll ; it is best obtained by treating fresh leaves with 50-60 

 per - cent methyl alcohol; if prepared from Heracleum it is 

 sparingly soluble in ether and crystallizes from that solvent 

 in steel-blue glistening prisms ; that prepared from stinging 

 nettles is slightly less soluble in ether and crystallizes in 

 triangular and hexagonal plates. 



By acting in moist ethereal solution in the absence of 

 alcohol, ordinary hydrolysis was effected with the formation 

 of the monomethyl ester of the chlorophyllin, namely, chloro- 

 phyllide 



/COOCH 3 

 C 31 H 29 N 3 Mg<-cOOH 



!> 

 NH 



this is an extremely unstable substance which forms green plates. 



The enzyme is sensitive to high temperatures, and when 

 boiled with alcohol it is gradually destroyed ; its activity is 

 greater at 25 than at 30. 



Chlorophyll appears to be always accompanied by the 

 enzyme, the amount increasing with the amount of chlorophyll, 

 and hence young leaves appear to contain less enzyme than 

 the older ones. In Pyrus Aucuparia, Mellitis Melissophyllum, 

 Stachys silvatica, Lamium maculatum, and Heracleum the 

 amount of enzyme is comparatively large. Urtica, Avena, 

 ordinary grasses, Sambucus, Platanus, Aspidium, Equisetum, 

 and Taxus may be conveniently employed for demonstrating 

 the effect of the enzyme by leaving the tissues in contact with 

 an alcoholic extract of amorphous chlorophyll ; practically all 

 the phytol is thereby removed. 



The enzyme is also able to effect the synthesis of phytyl 

 chlorophyllide (amorphous chlorophyll) from chlorophyllide 

 and phytol. 



The constitution of this alcohol phytol has been studied by 

 Willstatter and his pupils,* who find it to be an unsaturated 

 compound with a highly branched chain and a double bond 

 between the third and fourth carbon atoms of the chain. 



* Willstatter, Schuppli, and Mayer : " Annalen," 1919, 418, 121. 



