Macrocyclic sesquiterpene alkaloids

Fig. (12). Basic sesquiterpene cores of the macrocyclic sesquiterpenes alkaloids...

Fig. (13). Macrocyclic sesquiterpene alkaloids from Catha edulis...

Members of the Celastraceae family produce a wide variety of macrocyclic sesquiterpene pyridine alkaloids, which will be discussed below. In addition, various nicotinoyl esters of the base sesquiterpene structure p-dihydroagarofuran are produced, such as in the cangorins [160], wilforcidine [161], triptofordinines [162], and related compounds [163]. 

Khat, a drug produced from leaves and shoots of Catha edulis, is used as a stimulant, primarily in East Africa and Southern Arabia [167]. Interest in this drug led to investigation of the components of C. edulis, which included a number of macrocyclic sesquiterpene pyridine alkaloids, the cathedulins. 

Celastraceae also elaborate other, more complex, alkaloids, also polyester sesquiterpenes, incorporating a macrocycle derived from an evonic, wilfordic, cassinic or other type pyridine dicarboxylic acid with an additional alkyl chain of the basic eudesmane cycle at C-3 and C-7 (Table III). Celastraceae alkaloids are well-documented for the European and Asian genera, particularly Catha, Celastrus, Euonymus and Trypterigium but are relatively rare among the Latin... 

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