86 KARL FOLKERS 



this residue between petroleum ether and 90% methanol showed that 

 the activity remained in the petroleum ether solution. Distillation of the 

 petroleum ether phase left a residue showing one and one-half million 

 u./g. When this residue was dissolved in a petroleum ether-benzene 

 mixture and treated with magnesia, it was found that many impurities 

 were selectively adsorbed. Removal of the solvent left a residue show- 

 ing ten million u./g., and two molecular sublimations and many re- 

 crystallizations of this material gave a crystalline product which melted 

 constantly at 81.5-82°. It was effective in the biological test at a dosage 

 of o.oo2y and showed 500 million u./g. One hundred milligrams of 

 this crystalline compound was obtained from 55 gallons of crude cane 

 juice. 



We may look forward to learning more about the chemistry of this 

 antistiffness factor, 



Woolley demonstrated in 1941 the existence of a new growth factor 

 for the multiplication of certain organisms of Lancefield's group A 

 hemolytic streptococci (strains X40, S43, C203 and 594) on a chemi- 

 cally defined medium. It appeared that this factor was required for the 

 growth of other species of bacteria such as pneumococcus D39R. The 

 rate of growth of yeast on the Eastcott medium was also markedly 

 increased (Table XVIII). 



TABLE XVIII 

 A New Growth Factor Required by Certain Hemolytic Streptococci 



Growth factor (Woolley, 1941) for: a) Lancefield's group A hemolytic streptococci 



strains X40, S43, C203 and 594 



b) pneumococcus D39R 



c) yeast on Eastcott medium 



Sources : Liver "Fraction A," yeast and rice bran extracts 



Dialyzability : Liver "Fraction A" purification steps concentrates 



> (dialyzable form) 



(non-dialyzable form)- 



C^H^OH— H^O— HCl 



material 

 -> (dialyzable form) 



"Maximal unit" : Material/cc. to produce maximal growth and acidity 



Purification: Concentrates showed i m.u./iOy 



Properties : Not soluble in acetone, chloroform or ethyl acetate 



Not readily adsorbed by norite (non-dialyzable form) 



