92 



BIOCHEMICAL SYSTEMATICS 



70 



60 



50 



40 



30 



*S 20 



10 



1910 



1920 



1930 



1940 



1950 



1960 



Date 



Fig. 6-1. The effect of paper chromatography on the rate of 

 identification of new non-protein amino acids (Fowden, 1962). 



often of somewhat more limited distribution and therefore may be 

 effectively used as systematic characters. 



Since the vast majority of the non-protein amino acids are 

 probably not basic metabolites in the strict usage of the term, there is 

 some question as to the appropriateness of including amino acids along 

 with carbohydrates and lipids among basic metabolites. Whatever 

 group of substances to which the amino acids may be more appropri- 

 ately related, there are at least some historical reasons for beginning 

 the treatment of specific classes of compounds with a chapter on amino 

 acids. 



The technique of paper chromatography, which has been 

 primarily responsible for renewed interest in biochemical systematics, 

 had its origin in studies of amino acids (Consden et al, 1944). Partly 

 because development of new techniques in chromatography and re- 

 finements of older methods proceeded most rapidly in amino acid 



