ISOARBORINOL THROUGH GEOLOGICAL TIMES - EVIDENCE FOR ITS PRESENCE IN THE PERMIAN AND TRIASSIC

Optical rotation measurements and HPLC chiral separations using a beta -cyclodextrin phase, performed on aromatic hydrocarbons isolated from diverse geological sources, and belonging to the arborane or fernane t riterpenoid series, have shown that isoarborinol, one of the possible biological precursors, was abundantly present at the time of depositio n of Permian and Triassic sediments. This fact considerably reinforces the hypothesis that arborane derivatives in sediments, often found in abundance in lacustrine or lagoonal environments, must originate from microorganisms such as aerobic bacteria or algae rather than from ang iosperms, a group of higher plants whose evolution dates from the Cret aceous and currently believed to be the principal source of isoarborin ol.