3 CRYPTOXANTHIN 179 



Cryptoflavin crystallises from a mixture of benzene and petroleum ether in 

 beautiful lustrous plates, m.p. 171° (uncorr., in vacuum). The pigment exhibits 

 the same behaviour towards aqueous hydrochloric acid as cryptoxanthin 

 mono-epoxide. 



Solvent: Absorption maxima: 



Carbon disulphide 490 459 m/^ 



Benzene 470 439 m/x 



Chloroform 468 438 van 



Ethanol 460 430 m/z 



Cryptoxanthin di-epoxide C4QH5g03^^: This compound is formed by the 

 oxidation of cryptoxanthin acetate with monoperphthalic acid. 



CH3 CH3 CH, CH, 



\V \V 



C CHq CH« CHo CHo c 



/\ I I I I /\ 



CH2 C-CH=CH-C=CHCH=CH-C=CHCH=CHCH=C-CH=CHCH=C-CH=CH-C CH, 



)o 0( 



CH2 C C CHOH 



\ /\ Cryptoxanthin di-epoxide y^^\/^ 



CHa CH3 H3C CHj 



Cryptoxanthin di-epoxide crystallises from a mixture of benzene and petro- 

 leum ether. M.p. 194° (uncorr., in vacuum). 



Solvent: Absorption maxima: 



Carbon disulphide 503 473 m/i. 



Benzene 486 455 m/n 



Chloroform 482 453 mfi 



Ethanol 473 442 m/i 



With concentrated aqueous hydrochloric acid the di-epoxide gives a dark 

 blue colouration which is stable for several days. 



Cryptochrome C4(,H5g03 : 



CH3 CH3 CH, CH, 



C C 



CH2 C^=CH CH3 CH3 CH3 H3C CH=C CH2 



CH2 C CH-C=CHCH=CH-C=CHCH=CHCH=C-CH=CHCH=C-CH C CHOH 



CH2I Cryptochrome | CHg 



CHs CH3 



Cryptochrome is formed by the action of hydrogen chloride in chloroform 

 on cryptoxanthin di-epoxide, besides cr5rptoflavin and cryptoxanthin. Because 

 References p. 214— 2iy. 



