“…Next, we discuss in detail the biosynthesis of mangicol-type sesterterpenoids. Only a few C20/C25 terpenoids based on 5,11-bicyclic systems, such as ophiobolin, 34 , 35 cotylenin A, 36 and fusicoccadiene, 37 have been reported, 38 in contrast to those derived from 5,15-systems, such as quiannulatene, 5 , 39 sesterfisherol, 40 , 41 (+)-astellatene, 42 , 43 arathanadiene derivatives, sestermobaraenes, 44 and aspergildienes. 45 In the present study, IM8 was adopted as the simplest chemical model ( Figure 4 ).…”