I30 CAROTENOID HYDROCARBONS OF KNOWN CONSTITUTION X 



TABLE 34 



SOURCES FOR THE PREPARATION OF |8-CAROTENE 



TABLE 35 



a-CAROTENE CONTENT OF DIFFERENT CAROTENE PREPARATIONS 

 (kuhn and lederer*', KUHN AND BROCKMANN'^) 



Palm oil 



Green chestnut leaves 



Red berries 



Large pumpkin®' 



Green stinging nettles 



Paprica 



Spinach 



Grass 



traces 

 traces 



traces * 

 None 



P. Karrer and W. Schlientz"*'. 



Preparation 



Following WiLLSTATTER and Escher''^, finely cut carrots are dried, ground and 

 continuously extracted with petroleum ether at room temperature. The combined 

 extracts are concentrated as far as possible at 30-40° under reduced pressure and 

 diluted with an equal volume of carbon disulphide. From this solution the crude 

 References p. 16^-iyo. 



