4 MYXOXANTHOPHYLL 227 



partition between methanol and petroleum ether it is entirely epiphasic. 

 Myxoxanthin is adsorbed on calcium hydroxide and magnesium hydroxide, 

 but not on calcium carbonate, from petroleum ether solution. 



Spectral -properties: 



Solvent Absorption maxima 



Carbon disulphide 488 m^ 



Chloroform 473 m/x 



Ethanol 470 m^ 



Petroleum ether 465 m^ 



Colour reactions: On adding concentrated sulphuric acid to a chloroform 

 solution of myxoxanthin, the latter is coloured deep blue. Concentrated hydro- 

 chloric acid produces no colour change in chloroform. Addition of hydrochloric 

 acid to an ethereal solution produces a greenish-blue colouration. 



Myxoxanthin oxime C40H55ON: 



Brilliant, cinnabar-red plates, m.p. 195-196°. 



Solvent Absorption maxima 

 Chloroform 463 m// 



Myxoxanthol C40H56O : 



Deep red crystals, m.p. 169-172°. 



Solvent Absorption maxima 



Carbon disulphide 529 494 464 m/n 



Chloroform 508 474 441 mjj, 



Petroleum ether 495 465 431 m/n 



\V \V 



/\ I I I I \ 



CHg C-CH=CH-C=CHCH=CH-C=CHCH=CHCH=C-CH=CHCH=C-CH=CH-CH CH 



CH2 C-CHa HsC-C CH 



\ y Myxoxanthol ( ?) ' \ y" 



CHj ' CH 



I 

 OH 



4. MYXOXANTHOPHYLL C40H56O7 



In the course of investigations on Oscillatoria rubescens, Heilbron and 

 Lythgoe^^ discovered a new hypophasic pigment for which they proposed the 

 name myxoxanthophyll. The pigment occurs together with myxoxanthin, 

 xanthophyll and /3-carotene. In recent times myxoxanthophyll has been in- 

 vestigated by Karrer and Rutschmann^^. 

 References p. 25J-255. 



