Oxidation of Messel share kerogen using ruthenium tetroxide yielded se
veral series of hopanoid triterpenes which have been identified by syn
thesis. These compounds could originate from hopenes or hopanes of bac
terial origin linked to the kerogen; their structures indicate that in
corporation processes into macromolecular entities of their biological
precursors must occur at a rather early stage of diagenesis. (C) 1997
Elsevier Science Ltd.