1914] Clarence J. West 245 



pure pheophytin. By means of this process a laboratory worker is 

 able to work up 40 to 48 kilos of leaf meal a day, giving 200 to 250 

 gm. of pheophytin. When saponified it gives a mixture of phyto- 

 chlorine and phytorhodine. It is very sHghtly basic, not being ex- 

 tracted from its ether sokition with 25 percent hydrochloric acid. 

 It has no acid properties. It is waxy in nature and has not been 

 obtained in good crystalHne form. It reacts with metaUic salts to 

 form colored and very stable complexes. Thus, iron salts give a 

 greenish blue Solution; zinc acetate, bluish green; copper acetate, 

 brown Solutions which become green on dilution. When heated 

 with magnesium oxide and methyl alcoholic potash sol., magnesium 

 is introduced into the molecule, but under the influenae of the strong 

 hot alkali, the Chlorophyll which might result is decomposed. How- 

 ever, if the Grignard reagent is used, pure Chlorophyll a may be 

 obtained from pheophytin a. 



Pheophytin a is best prepared by extracting it from a mixture 

 of the two components with 30 percent hydrochloric acid. This 

 Separation must be carried out in the cold and as rapidly as possible 

 for the substance is quite easily hydrolyzed. 



The hydrolysis of pheophytin cannot be carried out with chlo- 

 rophyllase because the reaction is too slow. It is brought about by 

 heating with alcoholic hydrochloric acid for one hour, during which 

 the phytyl group is saponified off and replaced by a methyl group. 

 The mixture of methyl pheophorhidc a and h is fractionated by 

 means of 17 percent hydrochloric acid, the a form being removed.^* 



The methyl group may be removed by dissolving the ester in 

 ether (2 gm. in 4 liters) and extracting three times with one-half a 

 liter of 25 percent hydrochloric acid. The acid sol. is allowed to 

 stand at room temperature for two hours, when the saponification 

 is complete. The free pheophorbide is also obtained by the hy- 

 drolysis of pheophytin; 4 gm. of pheophytin are dissolved in 800 

 c.c. of ether and 2 liters of hydrochloric acid, and allowed to stand 

 from three-fourths to one hour, when the acid sol. is diluted and 

 extracted with 7 liters of ether. The components may be separated 

 by extracting a, using five portions of i liter each of 16 percent 

 hydrochloric acid. It may also be extracted with w/ioo ammonia 

 or potassium hydroxide sol, o.i percent sodium carbonate or i 



24 Willstätter : Afin. d. Chem., 387, 370 (1912). 



