CAROTENOLS AND OXYCAROTENOLS OF THE C40 SERIES 585 



considerably less than that of aphanin,^** suggesting that a considerable 

 portion of the molecule is not concerned with its biological reaction. 



Little is known about the composition or structure of flavacene or 

 aphanizophyll. Flavacene has some properties in common with mutato- 

 chrome. Aphanizophyll has been crystallized from methanol in prism-like 

 ciystals which form rosettes. They melt at 172-1 73 °C. 



(19) Gazaniaxanthin 



Gazaniaxantkin was discovered by Sch6n^°^ in the red-brown treasure- 

 flower gazania {Gazania rigens R. Br.), which is an African composite. It 

 has a structure indicated by the formula C40H56O, and appears from 

 spectroscopic data to be similar to 7-carotene. However, it has only 11 

 double bonds in place of the 12 present in 7-carotene. The hydroxyl group 

 is believed to be in the intact /3-ionone ring, since it is biologically inactive. 

 Zechmeister and Schroeder^^^ believe that gazaniaxanthin may be a dehy- 

 drorubixanthin with the following structure (C40H58O). 



HjC CHj HjC CH3 



p CH3 CH3 Cnj CH3 CH 



/\ hhIhhhIhhhhIhhhIhhh \ 

 HjC c • C : C • C: C • C : C • C : C • c: C • C: C* C: C • C: C- c: C* C CH? 



H^\ II II I 



C C C CHz 



"" C CH3 H3C c 



H2 Hz 



Gazaniaxanthin (?) 



Zechmeister and Schroeder^^^ were able to isolate 1400 mg. of gazania- 

 xanthin per kilogram of gazania flowers raised in Southern California, 

 while 100 mg. of 7-carotene and 60 mg. of /3-carotene were obtained from 

 the same amount of flower material. Cryptoxanthin and lutein were also 

 found among the carotenoids in the flowers raised in this country. On the 

 other hand, rubixanthin occurred in the yellow gazania (Gazania rigens) 

 grown in Portugal, in place of the gazaniaxanthin. The other pigments 

 found in the Southern California variety were also reported in the Portu- 

 guese flowers, with the exception of ciyptoxanthin, which was replaced 

 by an unknoNvn pigment. 



(SO) Petaloxanthin 



Zechmeister, Beres, and Ujhelyi^*^ separated a carotenoid from the 

 flowers of the Cucurhita pepo (pumpkin) which was called petaloxanthin. 

 Michaud and Tristan ^^° had likewise noted the presence of this pigment 



38^ L. Zechmeister, T. B6res, arid E. Ujhelyi, Ber., 6.9, 573-574 (1936). 

 390 G. Michaud and J. F. Tristan, Arch. sci. phys. nat. [4], 37, 47 (1914). Cited by 

 r. Karrer and E. Jucker, Carolinoide, Birkhauser, Basle, 1948, p. 326. 



