188 



VITAMIN D GROUP 



a commercial sample of hydrated ergosterol, are shown in Table VI. From 

 the table it appears that the ratio [a] 5461* [^Id is 1.27 at 20° and is prac- 

 tically independent of the solvent. The specific rotations, however, vary 



TABLE V 

 Solubilities of Ergosterol 



A. Data from Tanret^^^ 



widely with the solvent, being highest in chloroform, [afj' = —125.25°, 

 and lowest in acetone, [a ]d° = —92.0°. From the data of Bills and Honey- 

 well,^''^ it appears that the ratio is only slightly influenced by temperature, 

 being 1.30 at 20° and 1.27 at 25°. The values themselves, however, showed 

 considerable temperature effect. From the data of Callow, ^^ it appears that 



26oa E. M. Honeywell and C. E. Bills, J. Biol. Chem. 99, 71 (1932). 



