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Among the extended cyclic terpenoid biomarkers reported in literature thus far,the C-3 and/or C-2 methyl-substituted counterparts have been found either in bicyclic drimane series,or in pentacyclic hopane series. Even though the extended tri- and tetracyclic terpane series have been known over two decades,and their
Among the extended cyclic terpenoid biomarkers reported in literature thus far, the C-3 and / or C-2 methyl-substituted counterparts have been found either in bicyclic drimane series, or in pentacyclic hopane series. Even though the extended tri- and tetracyclic terpane series have been known over two decades, and their