256 



BIOCHEMICAL SYSTEMATICS 



Table 13-3. {Continued) 



Neoraimondia 



eichlamii 



grandiareolatus 

 macrostibas 



oleanolic acid, cochalic acid, chichipegenin, 



myrtillogenic acid, longispinogenin, maniladiol, 

 (y8-sitosterol) 



oleanolic acid, chichipegenin 



none 



Lemaireocereus (L. hollianus, L. laetus, and L. aragonii) lack triter- 

 penes, and two of these, laetus and aragonii, reputedly are doubtfully 

 included within the genus on botanical grounds. 



In the genus Myrtillocactus the chief triterpene is chichi- 

 pegenin (in every species except M. schenckii). Conversely, chichi- 

 pegenin occurs elsewhere only in Lemaireocereus chichipe. Djerassi 

 (1957) suggests that the two species may possibly have their generic 

 assignments interchanged. While it is evident that the cactus triter- 

 penes have provided very httle insight into cactus phylogeny at the 

 present time, the occurrence of a wide assortment of complex and 

 somewhat characteristic components within the family suggests that 

 an intensive chemosystematic study would be rewarding. 



Another class of sapogenins or steroid glycosides (including 

 the so-called "cardiac poisons") has been found to be of unusual sys- 

 tematic interest and will be discussed in some detail. The character- 

 istic structure of these compounds may be represented by the 

 cardinolid structure which follows: 



