CHLOROPHYLL AND THE CHLOROPLASTS 



359 



which is contained in phseophytin and consequently is also a portion of 

 the chlorophyll molecule. 



Phytol has played a very important part in the investigations of 

 chlorophyll ; phytol is a constant component of chlorophyll and comprises 

 one-third of the chlorophyll molecule. That is, the phytol content is never 

 more than 33 per cent of the chlorophyll. It has been observed that 

 some chlorophyll preparations contained very little phytol and it had 

 been reported, that from the latter preparations crystalline chlorophyll 

 was most easily obtained. It is now realized that this crystalline sub- 

 stance which was taken for chlorophyll is not chlorophyll as it exists 

 in the chloroplast, but an altered chlorophyll-like compound produced by 

 the action of an enzyme. When the chlorophyll is extracted rapidly from 

 the leaves, the phytol-content is one-third of the chlorophyll. If, how- 

 ever, the extraction is slow and the leaf powder is in contact with alco- 

 hol for a long time, the amount of phytol is low. In the leaf there 

 is an enzyme, chlorophyllase, which is capable of acting in an alcoholic 

 medium. Chlorophyllase, in alcoholic solution, produces an alcoholysis 

 of the chlorophyll with splitting out of phytol. The crystalline chlorophyll, 

 just referred to, was not true chlorophyll, but a methyl- or ethylchloro- 

 phyllid, i.e., the methyl or ethyl alcohol had replaced the phytol. These 

 methyl- and ethylchlorophyllids can be hydrolyzed to the corresponding 

 free acids. 



COO.CH3 

 Chlorophyll a C32H3oON4Mg < 



\COO.C20H39 



Chlorophyll b 

 Ethylchlorophyllid a 

 Ethylchlorophyllid b 

 M ethylchlorophyllid a 



Methylchlorophyllid b 



Chlorophyllid a 

 Chlprophyllid b 



C,,H,,0,NMg < 



C32H3oON4Mg 



COO.CH3 



COO.C20H39 

 -COO.CH3 



COO.C2H5 



/COO.CH3 

 C3.H,gOoN4Mg< 



^COO.CaHs 



C32H3oON4Mg 



COO.CHc 



C32H2802N4Mg 



COO.CH3 

 COO.CH3 



COO.CH3 

 C32H3oON4Mg(COOH) . (COO.CH3) 



C32H2802N4Mg(COOH) . (COO.CH3) 



