44 FEMALE BITTERLING I 



purification and under control of elementary analysis. 



Pregnanediol glucuronide was precipitated, by means of 

 acetone, from the extract purified by shaking out with 

 alkaline, according to the method of VENNING; as a matter 

 of fact we had already found out during these investigations 

 that acetone precipitates the luteidin. In this way a brown- 

 coloured crystalline substance was obtained from the 75 1 

 urine, in a quantity of 67 mg/1, a value which is normal for 

 the urine of a pregnant woman. The melting point was about 

 220° C, and the substance disintegrated. Purification did not 

 go smoothly; only with much difficulty did we succeed in 

 obtaining a few fractions of low weight, and coloured almost 

 white. These crystals did actually contain glucuronic acid, as 

 was proved by the colour-reaction of TOLLENS. With naph- 

 toresorcinol and concentrated HCl, a bluish-violet colour 

 appeared, which could be shaken out with ether. The colour 

 reaction, however, turned out to be unsuited to quantitative 

 determinations, so that the presence of any foreign substance 

 could not be ascertained in this way. For, the curious thing 

 is that these thoroughly purified crystalline fractions, too, 

 are. still highly active; here, moreover, we can observe the 

 characteristic property of luteidin, i.e., reduction of the latent 

 period, although, as is known, the necessary condition for the 

 hydrolysis of pregnanediol is that it is acidified and boiled. 



The crystals obtained from the 25 1 extract were darker 

 in colour than those from the 75 1 extract, and yet they had 

 a higher melting point. The melting points were 260 — 263° 

 C and 240 — 246° C, respectively. 



Part of the, still impure, fraction was hydrolised by boil- 

 ing with HCl; from this white crystals were obtained, with 

 a melting point of 222° C, after it had been noticed that, at 

 180° C, the material began to sublimate, and redeposit itself 

 in another form of crystal. In the case of pregnanediol, 225° 

 C is usually found, whilst the value for the pure substance is 

 235° C. When, however, 16 mg of the substance obtained 

 was acetylised with acetic acid anhydride and some pyridine, 

 an acetate was obtained with a sharp melting point of 161,5— 

 162° C; a value lying exactly between that of the ordinary. 



