23 TORULIN 329 



ether by dilution with water and the petroleum ether solution is extracted with 

 90 % methanol. a-Carotene, /5-carotene and esterified astacene (astaxanthin ?) remain 

 in the petroleum ether layer. The hypophasic pigments are taken up in benzene 

 and chrbmatographed on calcium carbonate. Two main zones are formed, the upper 

 yielding astacene after saponification, while the lower contains the new pigment, 

 cynthiaxanthin. By elution with aqueous methanol and crystallisation from the 

 same solvent under petroleum ether, the pigment was obtained in small, yellow- 

 orange needles. After recrystallisation from aqueous ethanol the m.p. was 188-190°. 

 The yield was 1 mg. The pigment does not give a blue colouration with concentrated 

 aqueous hydrochloric acid. 



Solvent: Absorption maxima: 



Carbon disulphide 517 483 451 rrifi 



Petroleum ether 482 452 m/i 



23. TORULIN 



During investigations of the carotenoids of Torula rubra, Lederer'^- '^ 

 found besides ^-carotene and two unknown pigments present in very small 

 amounts, another new carotenoid for which he proposed the term torulin. 

 Later Karrer and Rutschmann'^ also isolated torulin besides torularhodin 

 (p. 330) from the same source. Torulin appears to be fairly widely distributed 

 in nature. Besides Torula rubra, it has been found in Sporobolomyces roseus, 

 Sporobolomyces salmonicolor , Lycogala epidendron^^ and Rhodotorula Sanniei'^'^. 



For the isolation of torulin, red yeast is extracted with acetone, the mixture of 

 pigments is extracted with petroleum ether after addition of water, and the petro- 

 leum ether solution is extracted with ethanoland saponified with ethanolic potassium 

 hydroxide. After working up in the usual way the epiphasic pigments are dissolved 

 in a little petroleum ether and the solution is allowed to stand in the cold to allow 

 considerable quantities of steroids to crystallise out. The mother liquors are then 

 chromatographed on alumina, the ^-carotene in the lower portion of the chromato- 

 gram is separated, andthetorulin, which is adsorbed above ^-carotene, is crystallised 

 from petroleum ether in the cold. The pigment is further purified by crystallisation 

 from benzene and methanol. 



Torulin melts at 185°. 



Solvent: Absorption maxima:''^ 



Carbon disulphide ..... 565 525 491 m/i* 



Pyridine 545 508 475 m^M 



Benzene 541 503 470 m/i 



Ethanol 520 486 456 m^ 



Chloroform 539 501 469 m/x 



Nothing definite is known at the present time concerning the chemical 

 constitution of the pigment. Lederer'^^ found a certain similarity between 



E. Lederer records absorption maxima at 563, 520 and 488 m^ in carbon di- 

 sulphide. 



References p. 341-343. 



