BIOCHEMICALLY IMPORTANT COMPOUNDS 207 



in the primaeval atmosphere) and ammonium phosphite, 

 Gulick postulates the following series of reactions 



H H 



HgNC^N -}- H4N — O — P — OH »■ HgN C NH — O — P — OH 



O NH O 



cyanamide ammonium guanidine 



phosphite phosphite 



OH 



I 



I 



-^ HgN — C NH P — OH 



II II 



NH O 



phosphoguanidine 



Thus there are obtained high-energy compounds which 

 could have arisen under the conditions of the primaeval 

 ocean. These compounds are similar to phosphocreatine, 

 which plays an important part as a reservoir of free energy 

 in muscle metabolism. 



Unfortunately Gulick's paper does not give any experi- 

 mental support for the possibility of the transformation 

 of guanidine phosphite with an energy of phosphorylation 

 of about 2000 - 3000 cal. into phosphoguanidine with an 

 energy of phosphorylation of about 12,000 cal. The author 

 only points out in a very general way that photochemical 

 energy or the energy of concurrent exothermic reactions could 

 serve for the carrying out of these reactions. But this is just 

 what needs to be proved. It would therefore be very desirable 

 to have direct experiments to substantiate the possibility that 

 phosphoguanidine or some other high-energy compound 

 could be formed under the conditions which existed on the 

 surface of the primaeval Earth, for the formation of sub- 

 stances of this sort in the primitive ocean would have been 

 an extremely important event. 



In his well-known book Time's arrow and evolutiorf°^ H. 

 Blum states explicitly that in his opinion the appearance 

 within the complicated mixture of primary organic sub- 



