442 MISSOURI AGRICULTURAL EXP. STA. RESEARCH BULLETIN NO. 12 



THE ACTION OF DIGESTIVE JUICES 



The following solutions were added to equal portions of carotin 

 and xanthophylls * in test tubes, and the tubes plugged with cotton 

 and set aside at 40 C. Observations for signs of decomposition were 

 made every day for five days. 



Tube i. Five cc. of 0.25 per cent HC1 solution of pepsin. 



Tube 2. Five cc. of 0.25 per cent HC1 solution of filtered gastric 

 juice from the fourth stomach of a Jersey cow. 



Tube 3. Five cc. of 0.25 per cent Na 2 CO 3 solution of trypsin. 



Tube 4. Five cc. of 0.25 per cent Na 2 CO 3 solution of extract 

 from pancreas of a Jersey cow. 



Tube 5. Five cc. of 0.25 per cent Na 2 CO 3 solution of trypsin 

 plus 5 cc. of fresh bile from a Jersey cow. 



Tube 6. Five cc. of 0.25 per cent NaCO solution of pan- 

 creatic extract 2 plus 5 cc. of fresh bile. 



1. The carotin and xanthophylls were isolated as follows: 200 grams of 

 air-dried, powdered, green alfalfa leaves were shaken with three litres of 10 

 per cent alcoholic petroleum ether for two days, and then with 1 litre of 

 CS 2 , until the solvent had taken up as much pigment as possible. The carotin 

 and xanthophylls were isolated from each extract and combined. Each 

 solution was now concentrated to 50 cc. and divided into ten parts. These 

 were put into test tubes and the solvent driven off at a low temperature. 

 The residues were used for the studies reported above. 



The carotin and xanthophylls were isolated from the alcoholic petroleum 

 ether extract as follows: The xanthophylls were removed from the extract 

 by shaking with an equal volume of 80 per cent alcohol. The carotin in 

 the petroleum ether was now freed from chlorophyll by shaking with an 

 excess of CaCO 3 , the solution was now evaporated into alcohol and trans- 

 ferred to ether by diluting with much water after the addition of ether. 

 The solution was freed from traces of chlorophyll that had escaped absorp- 

 tion by the CaCO 3 by shaking with 30 per cent alcoholic potash. The ether 

 was then freed from alkali with distilled water. This ether solution of 

 carotin was combined with the similar solution obtained from the CS 2 , ex- 

 tract as described below. The 80 per cent alcohol, containing the xantho- 

 phylls, was partially freed from chlorophyll by shaking with moist animal 

 charcoal for one hour. The pigments were then transferred to ether, the 

 remainder of the chlorophyll being removed by 30 per cent alcoholic potash 

 as in the case of the carotin. The ether solution was then washed free 

 from alkali and added to the xanthophylls obtained from the CS 2 extract 

 as described below. 



The carotin and xanthophylls were isolated from the CS 2 extract as follows: 

 The extract was concentrated into 95 per cent alcohol and after filtering was 

 saponified with KOH. The pigments were extracted from the soap with 

 ether. The ether was washed free from alkali and evaporated into alcohol. 

 The carotin and xanthophylls were separated by differentiation between 

 petroleum ether (b. p. 30-50 C.) and the alcohol. 



2. The pancreatic extract was prepared by extracting a freshly ground 

 cow's pancreas with 150 cc. of 30 per cent alcohol for 24 hours, straining 

 off the extract, filtering and neutralizing with KOH and 0.5 per cent 

 Na CO 3 . To prepare the above solution an equal volume of 0.5 per cent 

 Na 2 CO 3 was added. 



