TERPENOIDS 



A rather heterogeneous group of substances is 

 actually included under terpenoids, yet with few 

 exceptions the compounds may be conceived as 

 structural derivatives of the five-carbon compound, 



isoprene. 



CH3 



CH2=C-CH=CH2 



Isoprene 



Recently, the six-carbon compound, meval- 

 onic acid, has been found to be an important 

 precursor in cholesterol synthesis and is suspected 

 to be involved also in the synthesis of several other 

 classes of isoprenoid compounds such as terpenes^ 



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