ALKALOIDS 1 67 



/ 1 



Fig. 9-1. Circular chromatograms showing alkaloid variation in 

 individual plants of Baptisia leucophaea from a single population. 

 Leaf samples were from plants of similar stage of development col- 

 lected at the same time. (Courtesy of B. R. Brehm) 



with amino acid metabolism, and environmental factors may have a 

 powerful effect upon free amino acid concentrations. It is therefore 

 understandable that alkaloids may in certain cases be quite sensitive 

 to environmental factors. 



If it were established that alkaloids served some important 

 role in the plants in which they occur, additional systematic signif- 

 icance might underlie their presence; for example, the alkaloids 

 would, in turn, be related to other special physiological attributes of 

 the plant. However, in general, the role of alkaloids in the plant is un- 

 known. They have been regarded as sources of protection against in- 

 sects, organic waste products (detoxification products), regulatory de- 

 vices, or even energy sources, but Httle or no direct support of any of 

 these hypothetical functions is available. It is beyond the scope of 

 this book to explore the possible roles of alkaloids in detail. The 

 possibility that alkaloids serve as detoxification mechanisms in which 

 the products are collected in vacuoles is interesting however. Alkaloids 



