SEARCH Articles Figures Tables 17a -hopanes 21a-H-Hopanes Hopan Hopan-28,22-olide Hopan-7/?,22-diol Hopane Hopane Hopane Group Hopane epoxide Hopane rearrangement Hopane triterpene Hopane triterpenes Hopanes and Neohopanes Hopanes isomerization Hopanes methylated Hopanes rearranged Hopanes structure Hopanes, Fernanes, Adinanes, and Filicanes Migrated hopanes Pentacyclic Triterpenes, Hopane Type Pentacyclic triterpenoids hopane Relative abundance of C35 hopanes