VOL. 12 (1953) PRECIPITABILITY OF CELL CONSTITUENTS AND MET.'^BOI ITES 27I 



La-salt of fructosc-i,b-diphosphatc 



Prepared from the pure Mg salt of fructose-i,6-diphosphate with LaClg and dried 

 in vacuo to Constance of weight shows the composition [C6H^Q04(POH)2]3La. This 

 corresponds to the otherwise^^ known type of acid salts of the sugar phosphate. 



La-salt of D-{ — ■)yphosphoglyceric acid 



Airdried'it shows the composition (C3H507P)3La2. 3H2O. The crystal water is com- 

 pletely lost at 105 °C. 



La-salt of fumaric acid 



After drying in vacuo it has the following composition (C4H204)3La2. 



Condensed inorganic phosphates such as pyro- and triphosphates will yield precipitates 

 with La-, Th- and uranyl-salts. These precipitates are soluble in meta- and pyro-phos- 

 phates. The ortho phosphates of the above 3 metals especially on slight warming are 

 soluble in Na-salts of pyro- and triphosphoric acid, as well as in NH4-citrate. 



Some useful effects have also been obtained with other metal salts e.g. Y(N03)3, 

 Zr(N03)4, Ino(S04)3, Ce(N03)3, PrCl3, NdCl3. 



Fructose-diphosphate is precipitated with these salts. Its yttrium salt is soluble in an 

 excess of Y(N03)3, but is reprecipitated on warming. The Zr-fructose-diphosphate is 

 soluble in monoethanolamine metaphosphate. 



Adenosinediphosphate yields a precipitate with PrCl3 which is soluble in an excess of 

 PrCl3. The same result is obtained with NdClg. 



Na-isocitrate yields precipitations with Y(N03)3, In 2(20)4)3, Ce(N03)3, PrCl3, NdClg. 



Some of the precipitations will appear on warming only. If the precipitating metal 

 salts are very acid, they will dissolve the resulting precipitates; the latter are also soluble 

 in an excess of the used organic reactants. 



Other metal compounds may possibly also be used for purposes of identification. 

 It was found that ferric, cupric, silver- and lead-salts of fumaric acid are precipitated 

 to a great extent, in some instances even quantitatively by means of Na-fumarate. Fe- 

 and Ag-nitrate are in praxi completely precipitated by sodium fumarate. 



We gratefully acknowledge the helpful assistance of Dr. Marianne Kreidl. 

 We thank Prof. Dr. F. Scheminsky (Innsbruck) for laboratory facilities at the 

 radiology station at his Forschungsinstitut in Gastein (Austria). 



SUMMARY 



The reported data show that many metabohtes and cell constituents even in considerable dilu- 

 tion may be precipitated by soluble salts of thorium, lanthanum and uranium. Characterization of 

 the resulting compounds is facilitated if the precipitants and possibly also the substances to be pre- 

 cipitated are radioactive. 



RESUME 



Les resultats exposes montrent que de nombreux metabolites et constituants cellulaires peuvent 

 etre precipites, meme a des dilutions considerables, par des sels solubles de thorium, de lanthane ou 

 d'uranium. La caracterisation des composes formes est facilitee si les reactifs precipitants et si possible 

 egalement les substances a precipiter sont radioactives. 



References p. 2^2. 



