C(14a)-homo-26-nor-17α-hopanes, a novel and unexpected series of molecular fossils in biodegraded petroleum
Abstract
A series (C27–C35) of pentacyclic triterpene hydrocarbons, the C(14a)-homo-26-nor-17α-hopanes, has been characterized in a biodegraded petroleum by gas chromatography–mass spectrometry and NMR structural determination of the C29 and C30 members; these biological markers reveal an as yet unknown transposition of the hopane skeleton.