CHLOROPHYLLASE 235 



For the monomethyl ester of chlorophyllin a Willstatter has 

 proposed the name chlorophyllide a, 



xCOOCH 



NH 



and adopting this nomenclature, amorphous chlorophyll would 

 be termed phytylchlorophyllide, while crystalline chlorophyll 

 would be ethylchlorophyllide. 



Chlorophyllase belongs to the same class of enzymes as 

 lipase ; the latter substance, however, is only able to hydrolyse 

 amorphous chlorophyll, replacing the phytoxyl group by 

 hydroxyl ; it cannot effect alcoholysis. 



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 



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 Melissopkyllum, 

 Stachys silvatica y Lamium maculatum, and Heracleum the 



