200 VITAMIN D GROUP 



vitamin D, a "product which is essentially characterized l)y its increasing 

 action on the level of blood calcium." According to the example, crystal- 

 line vitamin D, made from ergosterol, is irradiated in heptane in the ab- 

 sence of oxygen until its absorption maximum at 265 m/x substantially 

 disappears. The product is converted into the 3,5-dinitrobenzoate, which 

 is crystallized free of the suprasterols. Saponification of the dinitrobenzoate, 

 which is dextrorotatory, [oi]f = +33° in acetone, m.p. 130°, gives the free 

 drug as a whitish powder which is levorotatory, [af^ = —10° in chloroform. 

 (A similar anomalous difference in sign of rotation between dinitrobenzoate 

 and free sterol is noted in tachysterols^'^). 



The exceptionally low melting point, about 50°, casts some doubt on the 

 purity of the preparation, but the product is stated to be "practically 

 antirachitically inactive." It is worth noting that the patent description of 

 this drug, which was one of a series of blood calcium raising substances 

 then under investigation by the I.G. (following the Vigantol episode), 

 makes no mention of the term toxisterol and no reference to the absorption 

 spectrum of the product by which it could be identified as substance 248. 

 Although the isolation of toxisterol has never been described elsewhere 

 than in this patent and its European counterparts, the German workers 

 appear to have been familiar with toxisterol to the extent of publishing its 

 absorption spectrum showing the extinction coefficient."*^ 



h. Suprasterol I 



C28H44O. Three double bonds. General absorption below 250 m^u. [a] if = 

 -76° in chloroform. Melting point 104°. 



Suprasterol II 



C28H44O. Three double bonds. General absorption below 250 m/z. [a] if = 

 + 63° in chloroform. Melting point 110°. 



The products of extreme overirradiation, the end products of the series, 

 were designated Suprasterine by Windaus et al}^'^ in 1930. They recognized 

 two isomers, suprasterol I and suprasterol II, which they separated by 

 taking advantage of differences in the solubility of the allophanic acid esters. 

 The designations I and II do not refer to sequence of formation, but to the 

 order in which the two allophanates crystallize out of solution. The su- 

 prasterols, especially suprasterol II, are much more soluble in organic sol- 

 vents than ergosterol. They are unaffected by irradiation. They can be 

 distilled unchanged at 190° in vacuo. They do not precipitate with digitonin. 

 Of their color reactions, the most conspicuous is the intense red violet which 

 they give with chloral hydrate. They show no antiricketic activity at dosage 



313 A. Windaus, M. Deppe, and W. Wunderlich, Ann. 533, 118 (1937). 



314 A. Windaus, J. Gaede, J. Koser, and G. Stein, Ann. 483, 17 (1930). 



