10 



VITAMINS A AND CAROTENES 



a- or 7 -carotene. Lycopene, which is a straight-chain carotenoid, shows no 

 orovitamin A activity. 



TABLE III 

 Degradation Products of Lycopene and a-, /3-, and 7-Carotenes 



The formation of acetic acid as one of the degradation products indi- 



H 



cates^^*^ • ^2 the presence of unsaturated groupings of the type =C — C=. 



I 

 CH3 



21 P. Karrer and coworkers, Helv. Chim. Acta 11, (a) 751, (1)) 1201 (1928); 12, (c) 



285 (1929); 13, (d) 1084 (1930); 14, (e) 43 (1931). 

 " R. Pummerer, L. Rebmann and W. Reindel, Ber. 62, 1411 (1929). 

 23 R. Kuhn and A. Winterstein, Ber. 65, 1873 (1932). 

 2^ P. Karrer and coworkers, Helv. Chim. Acta 14, (a) 614, (b) 833, (c) 1033 (1931); 15, 



(d) 490, (e) 1158 (1932); 16, (f) 975 (1933); 17, (g) 417, (h) 1169 (1934); 18, (i) 25 



(1933). 

 25 R. Kuhn and E. Lederer, Ber. 64, 1349 (1931). 

 28 R. Pummerer and L. Rebmann, Ber. 61, 1099 (1928). 



27 P. Karrer and coworkers, Helv. Chim. Acta 12, 1142 (1929) ; 13, 1084 (1930) ; 14, 1033 

 (1931). 



28 R. Kuhn, A. Winterstein, and L. Karlovitz, Helv. Chim. Acta 12, 64, 904 (1929); 

 Ber. 64, 1732 (1931). 



29 H. H. Strain, J. Biol. Chem. 102, 137 (1931). 



»« R. Kuhn and A. Winterstein, Ber. 65, 1873 (1932); 66, 429, 1733 (1933). 

 8' G. MacKinnoy, ./. Biol. Chem. 112, 421 (1935). 

 32 R. Kuhn and H. Roth, Ber. 66, 1274 (1933). 



