The Original Formation of Amino Acids 



under the Action of Uhra violet Rays 



and Electric Discharges 



T. E. PAVLOVSKAYA & A. G. PASYNSKIÏ 



A. N. Bakh Institute of Biochemistry of the Academy of Sciences 

 of the U.S.S.R. 3 Moscow 



In the history of the formation of organic compounds on the Earth, special 

 significance is attached to the appearance of amino acids, since they are the start- 

 ing materials for the formation of peptides and protein-like compounds without 

 which life, in its turn, could not have come into being. The original formation 

 of amino acids from simpler compounds required an expenditure of energy to 

 activate the starting molecules. According to Oparin [i] the most significant of 

 the various sources of energy available in the prebiological history of the Earth 

 was ultraviolet irradiation from the Sun, which in regard to the Earth amounted 

 to about lo^o kcal/yr, a high proportion of which reached the surface of the Earth 

 at that time. Of lesser importance (probably not more than o-i-i-o% of this 

 value) were electrical discharges in the atmosphere, though these were also an 

 important factor in activating chemical reactions. 



As early as 1913, Loeb [2] observed the formation of glycine when silent 

 electric discharges were passed through mixtures of carbon monoxide, ammonia 

 (both obtained by the decomposition of formamide) and water vapour. In recent 

 years the formation of amino acids by passing electrical discharges through 

 mixtures of methane, ammonia, hydrogen and water vapour, imitating the 

 possible composition of the primaeval reducing atmosphere of the Earth, has 

 been studied in detail in Miller's [3] interesting work. In his experiments he 

 obtained glycine, a-alanine, /S-alanine, sarcosine, a-aminobutyric acid and 

 other compounds. 



K. Bahadur [4] has also published some interesting data concerning the 

 production of serine, aspartic acid, valine, lysine and other amino acids by the 

 prolonged action of sunlight on solutions of mixtures of paraformaldehyde, 

 KNO3 and FeClg. 



In the present work, we have studied the action of ultraviolet rays, as an im- 

 portant source of energy under the primaeval conditions of the Earth, on 

 solutions of mixtures of formaldehyde and ammonium chloride or nitrate, and 

 we have demonstrated the formation of amino acids under these conditions. We 

 have also repeated Miller's experiments using gaseous mixtures of somewhat 

 different composition. 



151 



