II. CHEMISTRY 209 



of vitamin D are destroyed by nitrites, this active substance must be differ- 

 ent from any known form of vitamin D. 



(17) The oldest of the minor forms is the antiricketic product which Bills 

 and McDonald^*" made in 1926 by treating cholesterol with fuller's earth. 

 Its potency was trivial, but interesting at the time in view of the irradiated 

 cholesterol which had been discovered the year before. The preparation was 

 repeated by Kon et al.^^^ and later the reaction was investigated by Yoder,*^^ 

 who identified the product as a sulfonated cholesteriline which resulted 

 from dehydration followed by sulfonation attributed to traces of sulfur 

 trioxide in the preheated acid clay. In a series of experiments Yoder and 

 his associates'**^ worked out the details of "antiricketic sulfonation" and 

 found that a considerable family of hydroxy steroids can be activated by 

 this means. One of the treatments was essentially the Liebermann reaction. 

 The potency attained was never high by irradiation standards, and the 

 healing action on rats was often accompanied by weight loss. Yoder and 

 Thomas'**' have reported that the product from cholesterol has an exception- 

 ally high chick-rat efficacy ratio. 



According to Raoul et a/.'*^ the action of sulfuric acid on cholesterol in the 

 Liebermann and Salkowski reactions results in the formation of an "ether- 

 oxide" of "tachysterol" (meaning ditachysteryU ether?), which, in an ioniz- 

 ing solvent, and without irradiation, transforms itself into "vitamin D." 

 The French authors state, "These experiments teach that it is not sulfo- 

 nation Avhich is the cause of the transformation of cholesterol into an anti- 

 ricketic product. There is really formed a vitamin D by the intermediary 

 of tachysterol under the sole influence of ionizations of various origins 

 (acetyl chloride, acetic anhydride, sulfuric acid) as two of us envisaged in 

 1947." The claim that vitamin D can be made from cholesterol by a simple 

 chemical treatment is most interesting, but the description of what happens 

 is unclear and lacks explanation of the required dehydrogenation step. In 

 a later paper, Raoul et a/.'*^ admit that the antiricketic compound formed 

 is not vitamin D3. It seems well established that Yoder's active preparations 

 are monosulfonated unsaturated hydrocarbons, but it may be that products 

 of the type studied by Raoul are also formed in the same reactions. 



"0 C. E. Bills and F. G. McDonald, /. Biol. Chern. 67, 753 (1926). 



3" L. Yoder, /. Biol. Chem. 116, 71 (1936). 



3J2 J. C. Eck, B. H. Thomas, and L. Yoder, /. Biol. Chem. 117, 655 (1937); J. C. Eck 



and B. H. Thomas, ibid. 119, 621, 631 (1937); 128, 257 (1939); L. Yoder and B. H. 



Thomas, ibid. 178, 363 (1949); hid. Eng. Chem. 41, 2286 (1949). 

 3" L. Yoder and B. H. Thomas, Arch. Biochem. and Biophys. 32, 14 (1951). 

 ^•'■» Y. Raoul, J. Chopin, P. Meunier, A. Gudrillot-Vinet, and N. Le Boulch, Compt. 



rend. 229, 259 (1949) ; Y. Raoul, J. Chopin, P. Meunier, N. Le Boulch, and A. Gu^- 



rillot-Vinet, ibid. 232, 1154 (1951). 

 3" Y. Raoul, N. Le Boulch, P. Meunier, J. Chopin, and A. Gu^rillot-Vinet, Comvt. 



rend. 232, 1258 (1951). 



