124 CAROTENOID HYDROCARBONS OF KNOWN CONSTITUTION X 



Solvent: Absorption maxima: 



Carbon disulphide 517 484 453 m/z 



Petroleum ether 480 452 m/f 



With free hydroxylamine, apo-3:i2-lycopenedial forms a dioxime which 

 separates in lustrous red crystals which sinter above 210°. 



Solvent: Absorption maxima: 



Carbon disulphide 510 480 m/i 



Ethanol 481 449 m/i 



Neo-lycopene C^qH^^: 



In the presence of small quantities of iodine, on standing at elevated 

 temperatures, or merely on standing in solution at room temperature for i or 2 

 days, lycopene is partly converted into an isomer, neolycopene (Zechmeister 

 and TuzsoN*^) . It has not yet been possible to obtain this pigment in a crystal- 

 line state. During chromatography on calcium hydroxide it gives rise to a 

 brown-red loosely adsorbed zone below that of lycopene. A cis-trans change 

 appears to be involved in this isomerisation. 



Solvent: Absorption maxima: 



Carbon disulphide 536 498 466 mfx 



Benzene 512 479 450 m// 



Chloroform 512 478 447.5 m/i 



Acetone 499.5 468 439 m/i 



Petroleum ether 499.5 468 439 m/z 



Ethanol 500 469 439 m/i 



Neolycopene is more easily soluble in organic solvents than lycopene. 



Lycopersene C4QH66: 



CH, CH, CH, CH3 



C CHo CHo CHq CHo Kj 



/ I I I I V 



CH CH-CH2CH2C=CHCH2CH2C=CH-CH2CH2CH=C-CH2CH2CH=C-CH2CH2CH CH 



CH2 C-CHa HsC-C CH2 



\ / Lycopersene \^ 



CH2 ' CHj 



Lycopersene has been prepared by Karrer and Kramer*^ by reacting 

 geranyl-geranyl bromide with sodium, a method analogous to that employed 

 in the synthesis of squalene^". 



Lycopersene is a rather viscous oil, which can be distilled at 0.02 mm 

 pressure in an air bath at 225-228°. It is a colourless compound. It absorbs 8 

 molecules of hydrogen chloride, forming a crystalline octa-hydrochloride 

 C40H74CI8, which after recrystallisation from acetone melts at 126°. 

 References p. 16^-170. 



