240 Willstätfer's Researches on Chlorophyll [Jan. 



crystalline form of Chlorophyll. Monteverde,^^ observing the same 

 in 1893, considered it pure Chlorophyll, regarding the amorphous 

 form as the decomposition product of the crystalline form. The 

 true relation was first shown by Willstätter. As mentioned above, 

 amorphous Chlorophyll is changed into the crystalline form by re- 

 placing the phytyl group with an ethyl or methyl group, and while 

 amorphous Chlorophyll is phytyl chlorophyllide, crystalline Chloro- 

 phyll is ethyl or methyl chlorophyllide. 



The preparation of crystalline Chlorophyll is carried out as fol- 

 lows : The dry meal is allowed to stand with 90 percent alcohol f or 

 12 hours (2 liters of alcohol for i kilo of leaf meal), the meal fil- 

 tered off with suction and washed with 2.5 liters of acetone, which 

 dissolves out the crystalline Chlorophyll that remains in the leaf 

 cells. The two extracts are combined, shaken with 150 gm. of talc 

 and during the course of an hour diluted with 4.5 liters of water. 

 The chlorophyllide separates in large glistening crystals, which are 

 filtered off with the talc, washed with 55 percent acetone and alco- 

 hol, then with petroleum ether and ether, taken up in alcohol, poured 

 into ether, the alcohol washed out with water and the ether dried. 

 After conc, the chlorophyllide crystallizes as three-sided tables. 



Decomposition products of Chlorophyll. The decomposition 

 products of Chlorophyll a and b are shown in the table on page 241. 

 From this table may also be seen the relations between the successive 

 stages in the degradation of the complex molecule, which may be 

 brought about by the consecutive application of acid and alkaline 

 hydrolyses. These relations will be indicated more fully in the dis- 

 cussion of the various substances named in the table. In the ma- 

 jority of cases it has been found easier to carry out the reaction on 

 the Chlorophyll mixture and then separate the new mixture into its 

 components. 



Decomposition with chlorophyllase, Chlorophyllase, act- 

 ing upon Chlorophyll in methyl alcohol sol. or, better, in a Solution 

 made up of 78 parts of acetone, 15 parts of methyl alcohol and 7 

 parts of water, for 40 hours, splits off the phytol residue and replaces 

 it by a methyl group, forming methyl chlorophyllide,^^ 



(CssHooON.Mg) (COOCHs)^ + 0.5H2O, 



20 Monteverde : Acta Horti Petropolitani, 13, 123 (1893). 



21 Willstätter and Stoll: Ann. d. Chem., 387, 351, 355 (1912). 



